Lets Go Green

Energy Saving Tips and Trick (newdream)

2008-12-15T21:11:00.000-08:00

Whether the outlook is for a cold winter or a tough economic forecast, it's a good idea to look for ways to conserve energy around your home. There are some simple steps (plus a few more complicated ones) that you can take around your home that can save money and carbon while keeping your family warm and toasty. Many households could save 20-30 percent on their household energy bills by implementing energy efficiency improvements.^*

Simple things you can do:

Turn your thermostat down several degrees when leaving the house for the day or extended periods of time. One easy way to do this is to purchase a programmable thermostat. You can also save by turning the thermostat down a couple of degrees all the time.
Keep your water heater temperature at temperature between 115-120 degrees. Consider getting a tankless water heater that only heats the water you need.
Limit your time spent in the shower to cut down on hot water usage. You can also install aerators to save on the amount of water you use while showering.
Wash laundry in cold as often as possible and line or rack dry your clothes.
Call your energy company to come out and check for leaks.
Call your utility company to ask about a year-round rate.
Defrost foods in the refrigerator before cooking.
Use compact fluorescent light bulbs in standard fixtures. Find out how much impact this simple step can have on Turn the Tide...
Replace or clean your furnace filters monthly. This could save up to 5% on your heating bill

Long-term energy saving investments:

Buy green appliances - many utilities offer rebates in return for purchasing efficient appliances through the Federal Government's Energy Star program.
Seal up your home. Seal air leaks and add insulation.
Weatherize your windows.
Upgrade your windows to those with multiple layers of glazing and approved by the NFRC (National Fenestration Rating Council).
When buying a new furnace or boiler, make sure you purchase one with a more efficient AFUE or adjusted fuel utilization efficiency.

Reducing your car's energy usage:

Rising gas prices at the pump are hitting all drivers in the pocketbook Below are a few tips on how to keep your car at its most energy efficient.

Go easy on the brakes and gas pedal, avoid hard accelerations, reduce idling and unload your trunk.
Get regular tuneups and scheduled maintenance to optimize efficiency.
Check tire pressure regularly. Under inflation causes increased wear and decreased gas mileage.
Take a break from driving: use mass transit; walk or bike whenever possible.

Energy Savings Benefits in Your Home
Save Money , Slow Global Warming and Do Something About Climate Change - all with one fantastic e-Manual. This e-Manual contains 120+ Tips and Secrets for Saving Money on Your Power Costs. Up to 30% of electricity used in the average home is wasted

Convert your Oil Car to Electric Car

2008-12-15T19:55:00.000-08:00

REVA Electric Cars (greenprophet)

BDO-I2I is looking to bring Indian-made electric cars onto the Israeli market. REVA Electric Car Company and consulting firm BDO-I2I are still finalizing the details, but there are reports imports could start before the end of January.

The news comes as Shai Agassi’s Project Better Place unveiled a protoype of its battery charging station earlier this week in Israel. The project aims to put electric cars on Israel’s streets en masse, but the project deployment date isn’t until 2010, a full year after REVA could be on the market.

REVA’s car is a fully-automatic battery powered hatchback that can be charged from regular 15 ampere electric outlets. A system of eight battery units form the 30 kg battery that gives the car a range of about 100 kilometers on just a six hour charge. The car is made of lightweight panels on a steel body. The manufacturer’s web site claims the cars are dent and scratch-proof, a claim Green Prophet finds a little suspicious.

In fact, TV show Top Gear filmed a segment mocking the REVA which featured a crash that is blamed for REVA’s UK G-Wiz 2008 sales figures being only about half of last year’s. Autobloggreen.com says REVA only expects to sell 750 cars this year, but hopes to introduce new larger models over the coming three to four years and boost sales to 30,000 units annually.

Currently the car is most readily available in India, but the vehicles are also available in Athens, Barcelona, London, Madrid and Oslo.

Prices for the Israeli market aren’t yet available, but the REVA G-Wiz sells for £7,995 in the UK.

REVA was started in Bangalore in 2001 after 7 years of research, and now has annual revenues of about $100 million.

Build Your Own Electric Car - Electric Car Plans - Electric Car Conversions

(build-electric-car)

Family Living Off the Grid with Renewable Energy takes Know How and Applies it to Electric Cars... Discovers the 'SECRET' to increasing the range of their Electric car up to an amazing 100 miles from a single charge with revolutionary discovery while building their own Electric Vehicle...How did they do it?

Dear Friends,

For the past 15 years our family has been living off the grid with only solar and wind power. We moved to our present location, built our own house and then we set to work to find alternative energy options that we could afford.

You see our family is no different than yours. We are just regular people who just want to make a difference in their lives. We wanted to lower our electricity costs. We wanted to lower our car expenses. It is getting very expensive out there so we figured out a way to beat it.

Today we live 100% Off-Grid and drive Electric Vehicles.

No we don't own those fancy new hybrids. We learned how to convert our cars to run on electricity at a cost we could afford. We figured out how to do it all for hundreds of dollars, not thousands of dollars. We had to.

And in so doing we figured out how to get 100 miles out of a single charge!

I would like to share with you exactly what we discovered and how we get such tremendous mileage from our revolutionary homemade electric car.

Would you like to discover:

Step by Step How To Convert a Car To Electric.

How to Cut Fuel Costs to Nearly Zero

How To Clean Up The Environment

How To Get Massive IRS Refunds

Can I tell you a secret? We're not very mechanically inclined. We needed a lot of help with this project. And we made a ton of mistakes. But, in all of those mistakes we learned something we can pass on to you so you don't have to make the same mistakes we did.

You see, this electric vehicle thing is only part of what has been a 15 year process to discover the ultimate way we can reduce expenses for living while still maintaining our present standards. We don't want to live without life's little luxuries, just like you.

In learning how to live off the grid we needed massive numbers of batteries and it was in looking for these batteries... that we stumbled onto the answer.

Our home requires a lot of batteries to store energy from our solar panels and wind generators. It was always so expensive to buy new ones, we needed an alternative. Then...

One summer a few years ago a friend of ours told us about a special kind of battery that we could get used (for free) in nearly dead condition and how he had come up with a way to recondition them to nearly new. He had been doing it for years for his RV that had a large solar array on it.

His Method worked fine if you were only going to recondition one or two batteries but we needed to recondition dozens so we had to figure out a better way to apply his process that would work for us. Using our system you can keep a whole bank of used batteries (like you need for an electric car) in nearly new condition for years.

What was so amazing was that these particular batteries had tremendous capacity. When we hooked them up it seemed like our home was always full of power to use. Where before we had to conserve our energy much more strictly to see us through especially cloudy or windless days.

I wanted to make an improvement to our property so I went to get a bunch more of these batteries. Then it hit me! As I was hauling them home in the bed of our pickup truck I thought: "Why not use these same batteries to convert our car to electric?" And that is just what we did...

Did I mention that I am no mechanic? Nearly flunked out of auto mechanics in high school. I just couldn't get it. But, electricity and batteries is somehow easier for me to understand. And it seems like everybody who has read these plans agrees.

We have done 3 conversions for friends and family so far, and decided to let the plans out to a few of our Off Grid Newsletter subscribers to see what they could do with them. And every one of them found they could do it too.

Now, these batteries are kind of heavy and we had to develop ways of mounting them in our car (and our truck) that would accomodate the weight. We found all sorts of creative ways that the average guy can do this too.

Of course we did get all sorts of people to help us when we started. The local high school shop teacher was interested in our project and offered to help, and our neighbors too... It seemed like there was always somebody here when we were working on them. Why? Because they wanted to do their own conversion and they just didn't believe me when I told them I was doing it myself. Most people just don't think it's possible.

"Well, pound nails to build your house, maybe", they would say. "But, build your own Electric Car? Doubt it."

So they would hang around and learn from watching us that even the could do it. Now they are smiling too, converting their own.

Living Off Grid means you have to be resourceful and it served us well in doing our first EV conversions. We have managed to find sources of nearly free DC motors which literally save thousands of dollars in doing a conversion to electric.

You may have heard that the cost to convert a vehicle is close to $10,000. I guess you could pay that much if you really wanted to. But with our new methods adapted from 15 years of living with renewable energy we will show you how to do an EV conversion for only a few hundred dollars... depending on your resourcefulness.

Buy The Tutorial here

Nuclear ? That's The Last Option but Not Now

2008-12-11T01:23:00.000-08:00

No Nuclear for Replacing Oil !!!
There still a lot of GREEN Technology
Nuclear is The Last Choice

Just Another comparison (nuclearpowerprocon)

2008-12-11T01:15:00.000-08:00

Comparisons

Comparing the Risks

Central to the debate about nuclear power is the question: How big of a risk do nuclear power reactors pose to power plant workers, the public, and the environment?

Advocates claim that nuclear power is one of our most benign large industrial operations,¹ it produces much less pollution relative to other fossil fuel sources,² and the public health threat posed by radiation has been greatly exaggerated by the mass media and dissident scientists.³ They also state that no member of the public has been injured or killed from a U.S. reactor accident at a commercial nuclear plant, and no plant employee has exhibited clinical evidence of serious injury from radiation.⁴

Opponents claim that the probability of a core meltdown accident occurring within the next 20 years is high,⁵ nuclear fission entails risks qualitatively different from those posed by other energy sources,⁶ and the public health threat posed by radiation has been greatly understated by nuclear power advocates.⁷ They also state that plant workers have been killed by accidents at commercial and government nuclear reactors,⁸ and that it is entirely possible that members of the public have died from cancer induced by radiation from a nuclear plant, because nuclear power's occupational hazards are manifested more in long-term cancer than in immediate lethality.⁹

All energy technologies present some level of environmental, occupational, and public health and safety risk:

Nuclear Fission

Accidents and sabotage at reactors, reprocessing plants, and waste repositories, and in waste transport, can release large quantities of radioactivity.

Routine emissions and exposures affect uranium miners, workers at reactors, reprocessing plants, and fuel-fabrication plants, and members of the public.

Fossil Fuels

Air pollution in the form of sulfur, oxides of nitrogen, photochemical oxidants, and particulate matter can cause and/or aggravate disease.

Water pollution from coal mines, oil refineries, drilling platforms, tanker accidents, and synfuel plants can damage wildlife recreation areas, commercial fisheries and domestic water supplies.

Acid rain can damage plants, kill aquatic life, accelerate leaching of nutrients, mobilize toxic metals, and alter microbial populations.

Carbon dioxide from combustion, accumulating in the atmosphere, can alter climate.

Accidents can injure and kill workers in coal mines, on drilling platforms, and at oil refineries, and can injure and kill workers and members of the public in gas explosions, and train and truck collisions.

Hydropower

Dam collapse through miscalculation, earthquake, or sabotage can kill thousands.

Lake filling destroys river ecosystems and fertile bottom land; dams block migratory fish and alter downstream ecological conditions.

Biomass

Deforestation from over-harvesting fuel wood accelerates erosion, increases flooding, and reduces land productivity.

Soil depletion from removal of crop and forest residues reduces fertility and water-holding capacity.

Air pollution results from biomass combustion.

Water pollution from synfuel plants and pesticide and fertilizer runoff from biomass plantations has effects as listed under fossil fuels.

Accidents injure workers in harvesting, and the public in biomass transport.

Photovoltaics

Toxic substances used in cell manufacture are occupational hazards, can contaminate water in manufacturing areas, and can be released from overheated or burning cells.

Wind

Accident possibilities include toppling towers, flying blades, and falls during construction and maintenance.

Aesthetic intrusion on mountain ridges, passes, and coastlines is feared by some.

Geothermal

Water pollution by dissolved salts and toxic elements in geothermal water can affect streams, lakes, and domestic water supplies.

Hydrogen sulfide gas is a toxic and odoriferous air pollutant.

Energy Efficiency

Indoor air pollution can be caused by chemicals in insulation or aggravated by reduced ventilation, increasing concentrations of radon, tobacco smoke, and other toxic substances.¹⁰

Numerous studies have been undertaken to determine and compare the quantitative risks of energy sources.¹¹ However, comparative assessments of the relative magnitudes of these risks is difficult both conceptually and analytically. Assessments of the expected damage to public health from fossil-fuel produced air pollution, for example, differ drastically as to the number of premature deaths that can be expected. A huge range of possibilities is also revealed in assessments of the impact nuclear-generated electricity can have on public health.¹²

Two important messages emerge from the above. First, one cannot conclude with any confidence either that the direct damages to public health from coal-fired and nuclear electricity generation are very large or very small. Second, the enormous ranges of uncertainty concerning the expected public health damages from the two energy sources mean that there is little basis for preferring one technology over the other on these grounds.¹³

Although scientists can provide information on the potential impacts of energy-source risks, in the end it is the public that will determine which risks are preferable, from which energy sources, and at what cost.¹⁴

¹ Manning Muntzing, editorial, "There are Good Reasons to Defend Nuclear Power," Los Angeles Times, June 15, 1984, 11:7.
² Ibid.
³ Bernard L. Cohen, "Exaggerating the Risks," in Nuclear Power: Both Sides, Michia Kaku and Jennifer Trainer (Eds.), op. cit., pp. 69-79.
⁴ Atomic Industrial Forum, Inc., "Nuclear Reactor Safety," information sheet, April 1983.
⁵ Commissioner James K. Asselstine, U.S. Nuclear Regulatory Commission, statement before the Subcommittee on Energy Conservation and Power, Committee on Energy and Commerce, op. cit., p. 2.
⁶ Denis Hayes, Nuclear Power: The Fifth Horseman, (Washington, D.C.: Worldwatch Institute, May 1976), No. 6, p. 29.
⁷ Fenn, op. cit., p. 172.
⁸ Wood, op. cit., p. 51.
⁹ Nader and Abbotts, op. cit., p. 165.
¹⁰ Holdren, op. cit., p. 141.
¹¹ For example, see Herbert Inhaber, Energy Risk Assessment, (New York: Gordon and Breach, 1982); International Atomic Energy Agency, "Risks and Benefits of Energy Systems," Vienna, 1984; and Nuclear Regulatory Commission, "Reactor Risk Reference Document," NUREG-1150, February 1987.
¹² Holdren, op. cit., pp. 142-143.
¹³ Ibid., pp. 144-145.
¹⁴ League of Women Voters, A Nuclear Power Primer, op. cit., p. 23.

More Deep about NUCLEAR

2008-12-11T01:02:00.000-08:00

1. The Dangers of Nuclear Power

An Open Letter to Physicists

Biological Ignorance

Some Biological Effects

Nuclear Power Plants

A Rational Energy Policy

Footnotes

Biological Ignorance

The history of atomic energy is one of repeated over-optimism, especially with regard to biological effects. Part of the reason for this, no doubt, is that physicists don't generally know very much biology. Nuclear physicists, for example, rarely spend a significant portion of their careers in the study of the biological effects of radiation.

One of the factors that is often ignored in talking about the release of low-level radioactive wastes into the environment is the fact that biological organisms can concentrate those wastes to a dangerous level. During the atmospheric testing of the 1950's, the Atomic Energy Commission predicted (correctly) that much less fallout would reach the ground in arctic regions than in temperate regions of the United States. They concluded (incorrectly) that Eskimos would not be in danger of accumulating dangerous amounts of fallout. They didn't know that food chains can behave in peculiar ways.

Lichens (a groups of composite organisms, each of which consists of an alga and a fungus living together) have no functional roots, and often grow on rocks rather than soil. They absorb their mineral nutrition in the form of dust taken directly from the air. As a result they absorb radioactive fallout directly, without the dilution and discrimination processes which operate when fallout is absorbed through roots. Caribou eat great quantities of lichen (many times their own body weight) and therefore take up excessive amounts of radiation from fallout. At the end of the food chain, caribou meat makes up a substantial portion of the Eskimo's diet, producing the unexpectedly large amounts of fallout radiation in their bodies. [1]

Another well-documented case of "biological magnification" occurred in Utah. During a series of tests in Nevada, fallout clouds passing over Utah (which the Atomic Energy Commission had said couldn't happen) deposited a scattering of iodine-131 on the grass. Being widely spread, this caused no alarming readings on outdoor radiation meters. But dairy cows grazed these fields, passing the radioactive iodine on to local children through their milk. Like ordinary iodine, it concentrated in the thyroid glands of these children, leading to abnormal growths in the thyroids of nine of these children almost 15 years later. The Atomic Energy Commission, which had completely ignored the danger of radioactive iodine as a hazard to man, finally admitted that in fact iodine-131 was responsible for the heaviest doses of radiation to man in the entire atmospheric testing program. [2]

Biological magnification is based on the principle that predators always consume many times their own body weight of their prey. If the prey happens to contain some substance that is stored in the body without being excreted (such as DDT), it follows that the predator will end up with a much higher concentration of this substance than can be found in the prey. Thus the substance appears in ever-increasing concentrations as you go up the food chain, and the full extent of this process may not become apparent for many years.

It is important to note that once such a substance is widely disseminated in the environment, even at low concentrations, it will continue to accumulate and concentrate as it goes up the food chain long after the substance has been discontinued in use.

One of the organisms that concentrates radioactivity is seaweed -- and in Wales and the Canadian Maritimes, people eat food made of seaweed. Oysters and shellfish also concentrate radiation. Algae concentrate radioactive phosphorus from the water 200,000 times; this substance also concentrates in the bones and scales of fish. In a river in which the concentration of phosphorus-32 is well below the level demanded for drinking water, fish may eventually become too radioactive for human consumption.

In Par Pond, where the Oak Ridge Laboratory dumped some of its low-level wastes, it was found that even when the concentration of cesium-137 was only 3 hundredths of a millionth of a millionth of a curie, the flesh of the bass caught in the pond contained 100 times this amount. Similarly, strontium-90 in the bones of bluegill was 1,000 times the level in the water, and radioactive zinc was 8,720 times the level in the water.

Caddis fly larvae in the Columbia River (where the Hanford nuclear plant discharges) achieved concentrations 150,000 times that in the water. Birds also concentrate radioactivity, and being higher up in the food chain, they end up with correspondingly higher concentrations. Thus swallows may carry 75,000 times the ambient level, because they feed on insects which in turn have concentrated it from algae which in turn have concentrated it 2,000 times above the level in the water. [3]

Since many of the radionuclides released from nuclear plants have long half-lives, their presence in the environment will be essentially cumulative. It is therefore most important to ask what the long-term of small doses of radiation may be.

Some Biological Effects

Time-lag factors are something which physicists are just not used to taking into account, and -- quite frankly -- they have very little experience to draw on in their particular field of study. It may take twenty years or more before the biological effects of exposure to radiation become known. Studies of the, survivors of Hiroshima and Nagasaki showed that all kinds of cancer had a very much higher incidence among those who had been exposed to radiation, but that these cancers did not develop until 5, 10, 15, or 20 years after the event.

There is a "latency period" during which no increase in the incidence of cancer is observed -- and then comes a whopping big increase. For leukemia, the latency period is about 5 years, whereas for other types of cancer it can be much longer -- for thyroid cancer (as hinted above) the latency period is about 13-15 years. Studies of uranium miners as well as silver and cobalt miners (all of whom were exposed to radon gas in the mines) confirm these latency periods. [4]

Before stating Gofman's conclusions with regard to low-level radiation, it might be worthwhile to briefly state who he is, since he seems to be held in considerable scorn by some of the physicists around. He is a full professor in the Department of Medical Physics at Berkeley. Besides being an M.D., he also has a Ph.D. in nuclear physics from Berkeley. He is a co-discoverer of U-232, Pa-232, U-233, Pa-233, and of slow and fast neutron fissionability of U-233. He is also co-inventor of the uranyl acetate and columbium oxide separation processes for plutonium. He has taught in the radioisotope and radiobiology field for over 20 years, and has done research in radiochemistry, macromolecules, lipoproteins, coronary heart disease, arteriosclerosis, trace element determination, and x-ray spectroscopy -- as well as radiation hazards.

In 1963, responding to growing criticism and recognizing that it had made many serious errors in the past, the Atomic Energy Commission asked Dr. Gofman to become an Associate Director of the Lawrence Radiation Laboratory and conduct a thorough long-term investigation into the biological effects of radiation. This investigation took more than six years, and it included careful correlation of studies which had already been done on miners, survivors of Hiroshima-Nagasaki, people exposed to diagnostic medical and dental x-rays, radiation technicians, and even large populations living in different locations where the background radiation levels showed significant differences.

Incidentally, just recently (October 1972) Dr. Gofman was awarded the Stouffer Prize "for pioneering work on the isolation, characterization, and measurement of plasma lipoproteins, and on their relationship to arteriosclerosis. His methods and concepts have profoundly stimulated and influenced further research on the cause, treatment, and prevention of arteriosclerosis." (Quotation from the citation accompanying the award.) The Stouffer prize, which carries a $50,000 cash award, is one of the highest existing honours in the field of heart research.

The purpose of reciting these credentials is not to make Dr. Gofman seem an infallible godlike expert, but to indicate how absurd it is for any physicist to make light of his work without ever having studied it or the data on which it is based in any great detail. After all, physicists are not biologists -- and it would be surprising indeed if a physical knowledge of nuclear processes should make one an expert on the biological effects of such processes. How much weight, I wonder, would physicists give to a community of biologists who scornfully rejected the theory of relativity as ludicrous and patently absurd, because it didn't fit with their biological intuitions?

What exactly was Gofman's "controversial" conclusion? Simply this: that the biological effects of radiation (in terms of increased occurrences of cancer, leukemia, and genetic damage) are linearly related to the accumulated dose of radiation received, regardless of whether it's a big dose administered all at once or a small dose administered over a long period of time. (Even before his work, the International Commission on Radiological Protection and the U.S. Federal Radiation Council had stated clearly that it is unsound to count on any protection against cancer and leukemia from slow delivery of radiation.)

This observation agrees with the theoretical supposition, that if a cell is alive and able to reproduce after exposure to radiation, but with damaged DNA or RNA instructions, its descendants may become manifested as cancerous growths many years after the original exposure. The probability of a cell being damaged in such a way is presumably proportional to the dose of radiation, regardless of how it is delivered. Thus uranium miners have consistently displayed almost three times the incidence of lung cancer than the rest of the population, although the onset of cancer may be delayed from 10 to 20 years after initial exposure -- often, indeed, after the men have retired or taken up some other form of employment. [5]

If Gofman is right, then there is no such thing as a "safe" threshold level below which no damage is done, To argue that there's a "background level" of radiation anyway, so it's all right to expose people to radiation as long as it doesn't exceed the background level, is sheer sophistry of the worst kind. It amounts to saying that it is "acceptable" to have twice as many people die from cancer, leukemia, and genetically-related diseases than would have died from natural irradiation. Gofman figured that if the U.S. population were exposed to this dose (the dose the Atomic Energy Control Board considers "acceptable" here in Canada is three times larger!) there would be at least 32,000 additional deaths every year from cancers and leukemias, over and above the spontaneous rate of incidence of these illnesses, and a much higher number of deaths from genetic causes. [6]

The extent of genetic damage as a result of radiation exposure, though known to be great, is still a mystery. Since the defective genes will be passed on through successive generations, the full effects will not be known for a long time -- another "time-lag" effect, but on an even larger scale. Even such non-cumulative radionuclides as carbon-14 and tritium are potentially very dangerous in this respect. Being chemically identical to ordinary carbon and hydrogen , these isotopes can be built right into any type of living tissue, including DNA molecules, where they can wreak genetic havoc. Tritium may prove to be a major biological hazard. The advent of thermonuclear plants would make the tritium problem very severe indeed.

One of the problems with tritium is that it is very hard to control -- it leaks out of aluminum and stainless steel fuel canisters, and it passes most valves and seals. Incidentally, the Canadian reactor produces not only more high-level waste than its U.S, counterpart, but also very much more tritium. It is well known, of course, that the traditional radioactive pollutants are genetically very dangerous too. Strontium-90 (a chemical relative of calcium) accumulates in bone tissue, for example; but when it disintegrates it produces yttrium-90, which tends to lodge in the gonads, where it can cause damage to eggs or spermatozoa. [7]

Nuclear Power Plants

It is true that, under "normal" operating conditions, the amount of radioactive material released from a reactor through exhaust stacks or effluent water is very small in comparison with background levels. Nevertheless, the chemical properties of these substances may result in biological magnification, producing doses very much larger than anticipated. Moreover, these substances may tend to concentrate in one part of the body (iodine-131 in the thyroid, strontium-90 in bone, cesium-137 in muscle tissue) creating specialized hazards.

Professor Pendleton has shown that cattle thyroids in Utah were still displaying radioactive iodine in 1962; in view of the ban on atmospheric testing and the short half-life of iodine-131 (8 days), this could only come from reactors and reprocessing plants. In 1968 the U.S. Public Health Service confirmed the presence of radioactive iodine in cattle thyroids in Georgia, Iowa, Kansas, Louisiana, both Carolinas, Oklahoma, S. Dakota, Tennessee, and Texas.

The longer half-lives of other radionuclides (e.g. 28 years for strontium-90 , 33 years for cesium-137 , and 6000 years for carbon-14) makes it impossible to say for certain whether increased levels of these radionuclides are due to recent additions to the environment or have simply worked their way up through the food chain. For a long-lived substance, a thousand emissions of one curie each amounts to much the same thing as one emission of 1000 curies. Also, in times of abnormal functioning, sizable amounts of radioactivity may be released from nuclear power plants, and there are plenty of documented instances of this. [8]

But the really crucial consideration is the possibility of a major accident at a nuclear plant. A single 200 megawatt reactor, after one year of operation, contains more radioactive cesium, strontium, and iodine than the amounts produced in all the nuclear weapons tests ever conducted. These high-level wastes have to be perfectly separated from the environment, not just for 600 years, but for over 1,000,000 years -- far longer than any political entity has existed in the whole of human history.

Long term management of high-level radioactive waste is an extremely difficult problem, and any attempts to minimize it are in vain.

And what about accidents? In its famous Brookhaven Report of 1957, the Atomic Energy Commission indicated what the results of a single major accident at a relatively small reactor 40 miles from a city might be:

3,000 to 4,000 deaths immediately from radiation poisoning,

50,000 deaths later on from radiation-induced injuries;

up to 150,000 square miles of land contaminated,

not to mention

contamination of water supplies and

evacuation of half a million people.

The Report goes on to say that the probability of such an accident occurring is so low as to be almost inconceivable. But this is a very unscientific statement, as the probability of most major accidents is so low as to be almost zero. No doubt the probability of the Titanic sinking on its maiden voyage was very small.

Anyway, how do you compute the probability of an accident? Do you count on the possibility of sabotage? (It would make an even bigger splash than kidnapping Pierre Laporte). Or the possibility of war? (What would happen if an old-fashioned conventional bomb were dropped on such a reactor?) What about the possibility of an airplane crashing into a reactor? (Remember, Pickering is also going to be the site of a huge airport. Only last month we witnessed the spectacle of a band of hijackers threatening to crash the plane they had hijacked into a nuclear installation. It could happen accidentally too.)

All of this doesn't begin to consider the very real possibility of a large industrial accident occurring within the plant as a result of mechanical and/or human failure. Accidents have occurred at Chalk River (resulting in the release of 10,000 curies of fission products), the Enrico Fermi plant outside Detroit (leading to a partial meltdown of the core and fears of explosion), the Windscale plant in Great Britain (which spewed vast quantities of radioactive debris into the environment), and others. In 1970 there was a close call at the huge Hanford reactor and a failure at the Oak Ridge Research Reactor, the later involving an "almost unbelievable" combination of 3 separate human errors, 2 installation errors, and 3 design errors. [9]

There are many other reasons why nuclear reactors are considered unsafe. One is the very serious problem of waste disposal. Another is the problem of transporting high-level wastes to a proper disposal site : how do you guarantee against an accident en route? Another problem is concerned with a black market in plutonium, which is the essential ingredient for making cheap atom bombs. According to expert testimony, it is by no means inconceivable for a terrorist group of moderate means to manufacture a home-made atom bomb. (Instead of holding an airplane hostage, they could hold a city hostage!)

Another problem, often overlooked, is the mountains of radioactive uranium tailings which have been shown to be potentially dangerous sources of radioactive contamination. In the U.S. there are now 30 million tons of this sand-like stuff, generally lying in uncovered heaps, being washed into water systems by wind and rain. The water in the San Miguel River in Colorado was found to contain 30 times the "acceptable" level of radiation, while algae and alfalfa were much more heavily loaded, as a result of uranium tailings being washed into the river. There is also the matter of thermal pollution, which is again a complex biological question, not to be dismissed lightly. [10]

A Rational Energy Policy

Energy consumption has been doubling in Canada every ten years or so. In large part, this is the result of intensive advertising to "Live Better Electrically", combined with preferential rates for large users of electricity. This growth in electricity consumption is related more to the production of garbage than to the quality of life -- for example, aluminum (requiring huge amounts of electricity for smelting) is increasingly being used for disposable beer cans and TV Dinner Trays.

The first priority in any energy policy should be to reverse these trends by urging people to use less (not more) electricity, as is being done by Consolidated Edison of New York, and by eliminating preferential rates for electricity gluttons. [11] There should also be a radical new policy of honesty with the public, to find out whether they are actually willing to take the risks in order to get more electrical energy. At present, they are lulled into thinking that there are no risks associated with nuclear energy.

In the Atomic Energy of Canada Ltd. report to the Nanaimo Chamber of Commerce , entitled "Nuclear Power for Vancouver Island", it was stated that "At very low doses, radiation is harmless -- that is, physiologically tolerable." That is a lie, and the Atomic Energy of Canada Ltd. knows it -- or should know it.

To someone who dies of leukemia, it doesn't much matter whether it was caused by a large or small dose of radiation. It's a bit like the photoelectric effect: the magnitude of the effect is independent of the intensity of the dose, only the frequency of the effect is dependent on dosage. Moreover, there is reliable evidence indicating that infants and children are far more susceptible to damage from radiation than an adult, and foetuses are more sensitive still, presumably because of the much more rapid division and growth of their cells. In the vicinity of a nuclear plant, there is no way of preventing these young people from accumulating radiation internally.

It has been shown that a single diagnostic x-ray to the abdomen of a pregnant woman can increase the chance of the unborn child developing childhood cancer or leukemia by 50 percent.

X-rays can be avoided; food cannot. Thus the question of nuclear power is an ethical question of great scope, and the people who are going to take the risks should be asked whether they are willing to have a small number of human sacrifices to pay for more electricity. [12]

Small? Well, assuming, of course, that there are no major accidents.

Footnotes

See chapter 2 of Science and Survival by Barry Commoner for an account of the arctic fallout question and the iodine-131 scandal in Utah.

In 1960, Dr. Knapp (a member of the Atomic Energy Commission's Fallout Studies Branch) was asked to write a report on "The Contribution of Hot Spots and Short-Lived Activities to Radiation Exposure in the US from Nuclear Test Fallout". Just before this paper was published, he made what he called a "startling discovery". He found that the Atomic Energy Commission had totally overlooked the effects of iodine-131 during the period 1951-1953 through a total lack of any monitoring for this substance. He also found that the dosage of iodine-14 had been underestimated by as much as 1000 percent in certain parts of the USA. For instance, he reckoned that infants in the town of St. George Utah, had received doses of from 120 to 440 rads to their thyroids, as a result of the heavy fallout from the 32 kiloton shot HARRY, which was exploded 120 miles from the town on May 19, 1953.
In 1963, Drs. Pendleton and Mays testified that approximately a quarter of a million children in the state of Utah may have been exposed to average thyroid doses of 4.4 rads prior to age 2, and that in 1953, several hundred infants in St. George (Utah) received doses to the thyroid ranging from 136 to 500 times the maximum permissible dose. See Fallout, Radiation Standards, and Countermeasures, JCAE Hearings, Part I (June 1963) and Part II (August, 1963).
In late 1962, the Atomic Energy Commission admitted that radiation dosage from iodine-131 may have reached 1.5 rads/year in some parts of the country (New York Times, October 18, 1963). While still far below the estimates of Knapp, Pendleton and Mays, these doses are the largest that the Atomic Energy Commission has ever admitted to in connection with fallout in the U.S.A.

Most of these figures can be found in Sheldon Novick's book, The Careless Atom. However, any book on radioecology will provide similar information -- see for example Radioecology of Aquatic Organisms by Polykarpov (translated from Russian).

Information about latency periods can be found in any recent book on the biological effects of radiation. For some time, it was erroneously believed that leukemia was the only cancer that resulted from low-dose exposure; it is now well-established that almost all other kinds of cancer can also result. The reason these other cancers were missed before is that they have a much longer latency period. Today it appears that the risk from low-dose radiation is at least 20 times greater than was thought 20 years ago, when the radiation standards were set.

For a complete account of the callous disregard for minimal safety standards in US uranium mines until very recently, see Peter Metzger's excellent book, The Atomic Establishment.

'Population Control' through Nuclear Pollution, by Arthur Tamplin and John Gofman.

Joshua Lederberg, Nobel Prize winner in Genetics, estimates that if the entire U.S. population were exposed to the maximum permissible dose of radiation, then the extra public health burden due to genetically related diseases induced by radiation would eventually cost 10 billion dollars a year. (Washington Post, July 19, 1970). His estimate is based on a 10 percent increase in mutation rate at this dose level. Gofman and Tamplin have estimated that mutations may increase by as little as 5 percent or by as much as 50 percent at this dose level. The dangers of carbon-14 have been pointed out by Linus Pauling (winner of two Nobel prizes) among others. Useful information about tritium can be found in a 1968 Atomic Energy Commission publication by D. G. Jacobs, entitled "Sources of Tritium and its Behaviour upon Release to the Environment"

Chapter 8 of The Doomsday Book by Gordon Ratty Taylor contains much valuable information of this kind.

The 3 major accidents that are mentioned here and the Brookhaven Report are all well described in The Careless Atom by Sheldon Novick.

Waste disposal is discussed in many books. The most recent scandal, the "Salt Vault" episode, is described in The Atomic Establishment by Peter Metzger. Articles have appeared in the Wall Street Journal (June 18, 1968), Science magazine (April 1971), and many other places regarding the plutonium problem. For information on uranium tailings, see The Atomic Establishment by Peter Metzger or The Great American Bomb Machine by Roger Rapoport.

An excellent article in Science (December 8 1972) argues that we could cut our energy consumption by 1/4 without any significant changes in life-style. Consolidated Edison of New York has already begun to advertise for less rather than more electrical consumption. It has been proposed by many people that large users of electricity should be charged more per kilowatt-hour rather than less. There are also many articles dealing with alternative energy sources in the l972 issues of Science magazine and other places.

The study of the effects of radiation on foetuses was done by Dr. Alice Stewart in England. It is acknowledged to be one of the most careful studies ever done in the field of radiobiology. Her results were subsequently confirmed by Dr. Brian MacMahon of the U.S. (Harvard University) using American data.

2. Pros and Cons of Nuclear Power Plants

Whether you view nuclear power as the promise for a better tomorrow or a whopping down payment on a mutant-filled apocalypse, there's a good chance you won't be easily converted to the other side. After all, nuclear power boasts a number of advantages, as well as its share of downright depressing negatives.

Sergei Supinsky /AFP/Getty Images
This storage facility near the site of the Chernobyl Nuclear Power Plant currently houses nuclear waste.

As far as positives go, nuclear power's biggest advantages are tied to the simple fact that it doesn't depend on fossil fuels. Coal and natural gas power plants emit carbon dioxide into the atmosphere, contributing to climate change. With nuclear power plants, CO₂ emissions are minimal.

According to the Nuclear Energy Institute, the power produced by the world's nuclear plants would normally produce 2 billon metric tons of CO₂ per year if they depended on fossil fuels. In fact, a properly functioning nuclear power plant actually releases less radioactivity into the atmosphere than a coal-fired power plant [source: Hvistendahl]. By not depending on fossil fuels, the cost of nuclear power also isn't affected by fluctuations in oil and gas prices.

As for negatives, nuclear fuel may not produce CO₂, but it does provide its share of problems. Historically, mining and purifying uranium hasn't been a very clean process. Even transporting nuclear fuel to and from plants poses a contamination risk. And once the fuel is spent, you can't just throw it in the city dump. It's still radioactive and potentially deadly.

On average, a nuclear power plant annually generates 20 metric tons of used nuclear fuel, classified as high-level radioactive waste. When you take into account every nuclear plant on Earth, the combined total climbs to roughly 2,000 metric tons yearly [source: NEI]. All of this waste emits radiation and heat, meaning that it will eventually corrode any container and can prove lethal to nearby life forms. As if this weren't bad enough, nuclear power plants produce a great deal of low-level radioactive waste in the form of radiated parts and equipment.

Eventually spent nuclear fuel will decay to safe radioactive levels, but it takes tens of thousands of years. Even low-level radioactive waste requires centuries to reach acceptable levels. Currently, the nuclear industry lets waste cool for years before mixing it with glass and storing it in massive cooled, concrete structures. In the future, much of this waste may be transported deep underground. In the meantime, however, this waste has to be maintained, monitored and guarded to prevent the materials from falling into the wrong hands. All of these services and added materials cost money -- on top of the high costs required to build a plant.

Nuclear waste can pose a problem, and it's the result of properly functioning nuclear power plants. When something goes wrong, the situation can turn catastrophic. The Chernobyl disaster is a good recent example. In 1986, the Ukrainian nuclear reactor exploded, spewing 50 tons of radioactive material into the surrounding area, contaminating millions of acres of forest. The disaster forced the evacuation of at least 30,000 people, and eventually caused thousands to die from cancer and other illnesses [source: History Channel].

Chernobyl was poorly designed and improperly operated. While the plant required constant human attention to keep the reactor from malfunctioning, modern plants require constant supervision to keep from shutting down. Still, Chernobyl is a black eye for the nuclear power industry, often overshadowing some of the environmental advantages the technology has to offer.

Explore the links on the next page to learn more about nuclear energy.

3. csmonitor

In Kansas, where winds blow strong, the push for clean energy includes not only new wind turbines but also new nuclear-power plants as part of a "carbon-free" solution to climate change.

It's an idea that may be catching on. At least 11 new nuclear plants are in the design stage in nine states, including Virginia, Texas, and Florida, according to the Nuclear Energy Institute website.

But that carbon-free pitch has researchers asking anew: How carbon-free is nuclear power? And how cost-effective is it in the fight to slow global warming?

"Saying nuclear is carbon-free is not true," says Uwe Fritsche, a researcher at the Öko Institut in Darmstadt, Germany, who has conducted a life-cycle analysis of the plants. "It's less carbon-intensive than fossil fuel. But if you are honest, scientifically speaking, the truth is: There is no carbon-free energy. There's no free lunch."

Nuclear power has more than just a little greenhouse gas attached to it, when mining uranium ore, refining and enriching fuel, building the plant, and operating it are included. A big 1,250 megawatt plant produces the equivalent of 250,000 tons of carbon dioxide a year during its life, Dr. Fritsche says.

That's still much less than coal-fired power plants and natural-gas turbines. It even does better than solar power and small-scale hydro projects. However, the gap with solar is closing and emissions from manufacturing photovoltaic panels are now on par with nuclear, a new study funded by the US Energy Department finds.

Officials in the nuclear power industry say references to carbon-free energy in their promotions refer only to the power-plant operation – and are not intended to describe carbon emissions during the entire nuclear life cycle.

"Yes, absolutely there's carbon," says Paul Genoa, director of policy development for the Nuclear Energy Institute, which represents the nuclear power industry in the US. "Most studies have found life-cycle emissions of nuclear to be comparable with renewable. Some show nuclear to be extremely high, but we do not find those credible."

Neither do many researchers. A 2003 Massachusetts Institute of Technology study recommended vast expansion of nuclear power to make a dent in the climate-change problem. Princeton researchers also cited it as an option, although they acknowledged concerns about terror threats and potential accidents.

One University of Wisconsin life-cycle emissions study in 2003 found even lower carbon emissions for nuclear than for most renewables. "We found wind and nuclear fission to have the lowest greenhouse-gas emissions over their life-cycle," says Paul Meier, director of the energy institute at the university. "We didn't include biomass and some of the others now available."

Yet it's not so much nuclear's carbon emissions, which are still relatively modest, but its cost-effectiveness in reducing carbon-dioxide emissions globally that's the key question, researchers say. Few studies have addressed that question.

Long and interesting Debate between Nuclear Power vs Renewable Energy

2008-12-11T00:23:00.000-08:00

1. softpedia

The one thing both renewable energy proponents and nuclear reaction supporters agree on is that fossil fuels will be completely out of the picture in a few decades, mainly because they will have polluted the atmosphere too much by then, but also because they might run out eventually, leaving the world in a huge black-out. The race is now on to see which energy source will power up the future.

Right now, nuclear energy accounts for about 9 percent of the total electricity production worldwide, whereas renewable sources, including solar, geothermal, eolian and underwater, only generate about 6 percent. Predictions say that oil, coal and natural gases will be depleted in 50 years tops, so, by that time, technologies need to be set in place to cover the ever-increasing electrical necessities of the world.

The only chance for renewable energy to take the edge is for people to come up with new extraction methods that are not as costly as those currently available. Solar energy seems to be growing more efficient even now, with new technologies being devised to increase production, while minimizing the overall costs. Underwater turbines, which use deep-sea currents to generate electricity, have great potential, given the fact that they do not affect the environment and the animal species around them. In fact, areas where these turbines are located are banned from commercial activities.

Nuclear energy, on the other hand, is very expensive to build and production times are very extended. Crucial components are manufactured in but a few selected locations. Those factories almost never manage to cope with an ever-increasing demand in spare parts and this fact "bottlenecks" large-scale constructions. If the future of the global power grid is nuclear, then new facilities will have to be built by 2030, in order to avoid widespread, lasting black-outs.

Currently, nuclear energy has the advantage, because a small infrastructure is already built and results are visible. The International Atomic Energy Agency has announced that more than 40 nations, including Nigeria, Egypt and Turkey, have informed it of their intentions to start building their own nuclear power plants, to power up their own electrical grids. But this poses new questions, especially in regard to world security, seeing how converting a nuclear-powered electrical plant into an atomic bomb production facility is relatively easy.

2. nucpros

After a two-decade wait, a bill that aims to boost the development of renewable sources of energy is about to become law. All that the proposed Renewable Energy Act needs is the signature of President Arroyo.

In contrast to traditional energy sources like filthy fossil fuels, Renewable Energy sources are more environment friendly, can be tapped in many parts of the Philippines and help save the country billions of dollars, now spent to import petroleum and coal.

Renewable Energy sources include water, solar, wind, biomass and geothermal. The problem is that harnessing this kind of energy requires a lot of money up front in order to acquire technology as well as to undertake exploration, plant construction and other activities.

Take the case of geothermal energy-a high-fallutin' term for underground steam. In a volcanic country like ours, this resource is widely available. The problem is tapping geothermal energy sources require capital for exploring possible steam fields, usually in mountainous areas, building kilometers of winding roads to remote site, transporting tons of equipment, building work camps to house construction and operations personnel, etc.

Since the 1980s, the Philippines has gained much headway in harnessing its geothermal resources through the efforts of a subsidiary of the state-owned Philippine National Oil Company (PNOC), which last year sold off its Energy Development Corporation to a conglomerate led by the Lopezes.

Thanks to the pioneering efforts of Philippine National Oil Company and National Power Corporation, the Philippines soon became a world leader, and now second only to the United States, in geothermal power development.

Underground steam currently generates about 16 percent of the country's electricity needs. More potential geothermal fields await tapping. Enactment of the Renewable Energy Law is expected to accelerate the process.

Speaking at a recent conference in Iloilo, Sen. Edgardo Angara was reported saying that the new law would offer a range of incentives that should encourage fresh investments toward the Renewable Energy development.

Angara, who authored the Senate version of the Renewable Energy bill, was also reported saying that the growing energy needs and lack of power supply could trigger outages in the Visayas starting next year, followed by Mindanao in 2010 and Luzon in 2011.

The incentives for Renewable Energy investors include tax exemption for seven years. Afterward, the investors would be required to pay a 10 percent corporate tax, instead of the customary 30 percent.

Misguided proposal

The senators have made good on a promise made earlier this year by then-Senate President Manny Villar to expedite passage of the RE measure. Some of them, however, continue to entertain misguided ideas.

Take the case of Senate Bill 2665, which proposes the immediate re-commissioning of a mothballed nuclear power plant in Morong, Bataan. The bill ostensibly seeks "to revisit and utilize the nuclear power option" to address both global warming and the "shortfall in the electric generating capacity of the country in 2012."

SB 2665 was introduced by Sen. Miriam Defensor-Santiago on October 7. It was last reported to be undergoing deliberation by the energy and finance committees.

Environmental groups led by Greenpeace have registered their opposition to the proposal to commission the anomaly-ridden Philippine Nuclear Power Plant (PNPP), which was built at great expense by the Marcos regime. Environmentalists described the proposal as extremely dangerous and unwise.

As if the Three-Mile Island and Chernobyl accidents were not warning enough, a Greenpeace position paper contended that nuclear power has repeatedly failed to deliver on its proponents' promises and has proven to be a highly expensive and risky investment.

The construction and generating costs of nuclear power are greater than most renewable energy and energy efficiency technologies, Greenpeace stressed.

Nuclear energy further poses multiple threats to people and the environment from its operations, including the risks and environmental damage from uranium mining, processing and transport, the potential hazard of a serious accident, the unsolved problem of nuclear waste, and the risk of nuclear weapons proliferation.

Global warming

"You can't solve a problem by creating another problem," said Amalie Obusan, Greenpeace climate and energy campaigner in Southeast Asia. "To propose nuclear expansion in the name of climate change is stacking one potential catastrophe over another."

Obusan added: "Not only does it seem outrageous to dig up mistakes from the past, it is would be a complete waste of money that is much better spent on further development of the country's plentiful renewable energy sources-the real solutions to climate change."

Rehabilitating Nuclear Power Plant is projected to require about US$800 million, equivalent to the cost of a new power plant. According to Greenpeace, this amount will most likely increase, as experience with the Bataan plant showed.

Safety is also a foremost issue, Greenpeace said. Aside from the unsolved problems of nuclear waste disposal, which stays dangerously radioactive for hundreds of thousands of years, re-commissioning an outdated reactor model such as PNPP carries severe safety risks. Once a reactor has been built, improving safety features according to current standards is often an impossible task.

In contrast, Renewable Energy resources can provide as much as 57 percent of the country's energy needs by 2030, and 70 percent by 2050, with "new" renewables, such as wind, biomass, geothermal and solar energy, contributing as much as 58 percent to the energy mix, Greenpeace pointed out.

3. drunkenrantings

Hi Derek,

It's clear you hold high hopes for Nuclear Fusion, but I read the New Scientist, and the last article I read suggested that commercial fusion was probably 30-50 years away. It faces major technical hurdles... We need a solution today!

Planning on fusion being available to help with CO2 emmissions is like relying on the lottery to pay your mortgage - it's not a sensible course of action... To pay your mortgage you do work you know will pay you money, you don't play the lottery. Similarly, to provide the energy we need to live, we should be using simple, proven technologies, and we should be using them now.

You say:

Whilst I support most of your suggestions for generating renewable energy - none of these could feed energy into the national grid on a permanent basis.

But this is simply not true for: tidal, hydroelectric, methane digesters, rubbish burning... All these *will* produce a constant supply of energy to the grid. Sure, there are some which won't - notably wind (, wave) and solar, but these are in the minority.

Besides, you need to look at renewable power generation as coming from *all* these different sources. For the system to be robust and reliable we need a wide portfolio of energy generation methodologies. In combination - they *will* provide a constant input to the system. In fact, a system built from millions of small generators will inevitably provide a more constant and reliable flow of energy than a few tens of large ones.

It is true that the energy flowing into the grid will vary - and as I said before - we should be investing in the grid itself, providing it with storage (capacitance). There are many different ways of acheiving this.

You do then go on to list a wide range of viable renewable energy sources.

My main point here is this: If TAXES WERE REMOVED FROM RENEWABLES, they would become more PROFITABLE so BUSINESSES WOULD INVEST in providing a renewable energy infrastructure. This would cost the country nothing, in fact it would stimulate a whole new sector of industry, making new jobs, building expertise and IT WOULD STOP OUR CONTRIBUTION TO GLOBAL WARMING WITHIN 10 YEARS.

People underestimate the inventiveness of the British:

I would bet you that if we did stop taxing renewables, then in 15 years time, 10% of our energy will be coming from a renewable technology that doesn't even exist today. If the governmant provides the right economic climate for renewables to flourish, then they will. It really is as simple as that.

Nuclear power is a white elephant. And there's always the danger it'll go Rogue...

It seems utterly nonsensical to be building nuclear power stations for these reasons:

It's astronomically expensive. (£56Bn simply to clear up the current mess - that's before making any more of it!)
The overall reduction in CO2 emmissions is less than 5%
TERRORISM is supposed to be, alongside global warming, 'the greatest threat the world faces'. Nuclear power stations are, to a terrorist, a ready-made dirty-bomb. It is utterly INSANE to build a load of bombs around our country - ready to be set off by any slightly competant extremists. (I'd like to see them turn a tidal lagoon into a terror weapon - it can't be done!) Did you not see that documentary about security at Sellafield? (I think it was) - there was virtually *none*.
We STILL don't know how to safely dispose of the waste.
If there were no nuclear power stations in the world - there would be no way to secretly produce bomb material - like Iran is currently doing. Abolishing all commercial nuclear technology is the only way that non-proliferation will ever happen. (Nuclear research - i.e. fusion, is fine - it's just commercial scale operations that are the problem)

Nuclear power is touted to protect vested interests in this country, not because it makes sense. It provides a false hope, and diverts attention away from the one thing that actually will stop global warming - which is to *stop taxing renewables*. (The only people this policy would hurt are the oil companies, but the coutry as a whole would become richer - because we buy in most of our fossil fuels)

Government always, always comes up with overly-complicated solutions to simple problems. I think this is part due to the fact that most people in government are not trained in systems-analysis and design. They have never run their own business, and they like big schemes which make them look important.

The best solutions are always the simplest solutions. I build systems for a living... I have a rule:

If you truly understand the system, a simple elegant solution will be obvious.

The converse is:

If you don't have a simple elegant solution, then you don't understand the problem.

Nuclear power is about as far from a simple, elegant solution as it's possible to get. It creates more problems than it solves.

Reply From Derek

I never said that nuclear fusion would be producing energy for the national grid any time soon. I said that it had the highest possible potential for providing enormous electrical output for minimum material input and that research and devlopment should be funded to determine at some time in the future whether this technology had any chance of viability.

I gave no time prediction for this to be achieved, but I would be very surprised if any practical results could be achieved within several decades, if then.

However, that does not mean that we should not try to activate a system that would provide unimagineable power output from an incredible small material input. It may never happen, but we must not exclude it unless future research predicts that it is physically unatainable. Predictions in science have proved to be very unreliable. Albert Einstein said at one time that he could see no practical results from his theories on relativity, but look at how his theories on the relationship of time, mass, gravity and energy have changed the modern world - nuclear energy, space exploration, creation of artificial elements, etc.

You suggest that a multitude of small generaters would provide a more reliable output that a few tens of large generators. Well, that is what we presently have. The large coal, oil, gas, and nuclear generating stations have been producing a constant output at between 10kV and 15kV (There are some outside this range) directly from the generators and transformed to give a domestic mains supply of between 200 and 240 volts for the last half century, and earlier, supplying the current required whatever the load demanded.

( Note: In recent years the EU has determined that the domestic mains supply voltage should hover around 230V).

How would your multitude of small generators provide a synchronised ac voltage of 230V to domestic users nationwide when most of the generators you envisage using cannot generate power on an unfailing permanent basis. It might possibly work if the national grid was broken-up into a patchwork of areas of a relatively small number of consumers using a large variety of generating sources to allow for drop-out due to failure of some of the generators due to lack of input: ie, wind, wave, straw, vegetable oil, methane, etc.

Capacitance is used to balance out the masive inductance of the wires in the lines and transformers of the distribution system, but cannot help unless the output from the generators is maintained.

One natural energy source is geo-thermal and on a large enough scale could certainly provide energy on a permanent basis.

By the way, you say that taxes should be removed from renewable sources of energy. but doesn't the government subsidise many of the windfarm projects and it will take over 2000 wind generators to supply the same output as one fairly modern power station generator.

To supply anywhere near the toal output required for the nation, when the wind blows, over 30,000 wind generators have to be built - but in an anti-cyclone over the UK, the total output will be zero. Not exactly a reliable sourse of power some would say. I just do not want my country to be despoiled by an average of four wind generators for every sqare mile of the United Kingdom.

I see that ITV is frightening people into believing that global warming is upon us by showing ice-cliffs dropping into the sea in massive amounts. Well, it is Summer down there in the Antarctic, and in Summer, the ice melts, so what we need to know is the differential between normal Summer ice-melt and the actual ice-melt now occurring. Why don't ITV show the sea freezing over in the Arctic where it is Winter? We need proper information from proper scientific research, not scaremoingering non-science for vulnerable TV viewers.

Well, I'm sorry we have different views about how we should generate our country's energy, but I respect your right to hold your own opinion and I hope you respect mine. Let us hope that the right decisions will be made to ensure that future generations inherit a world where the air is clean and forests, plains and deserts provide a viable living to all the creatures that exist on our planet at the present time.

Very best regards,

Derek.

4. renewableenergyworld

Q: A senior nuclear power exec claimed at a recent seminar that the environmental footprint of a nuclear power station was 100 times smaller than an onshore windfarm. (no sizes given unfortunately). What are the comparable eco-footprints? -- Polly H., London, United Kingdom

A: According to wind energy expert Tom Gray (and Director of Communications and Outreach at the American Wind Energy Assocation), "My rule of thumb is 60 acres per megawatt (MW) for wind farms on land." According to the Energy Information Administration, The Fort Calhoun 476 MW nuclear power plant, operational since August 9, 1973, is located on 660 acres near Omaha, Nebraska and has an easement for another 580 acres, the acreage being maintained in a natural state (see Fort Calhoun link below). So on the face of it, on the same 1200+ acres, nuclear gets 480 MW versus 20 MW for wind, or 40 times more. But the capacity factor for the nuclear plant hovers above 80% and wind is approximately 30%, so clearly the '100 times more' claim seems to be 'on the mark' if you chose to forget the nuclear fuel cycle. We now have active farming onsite at large windfarms, and there is no reason to believe we could not also harvest crops between the large wind generators for biomass electric power, which could increase electrical output of the same acreage substantially. But a nuclear power generation plant is not an independent entity like wind. A number of processes are needed to keep the generation plant operational, most of which take place elsewhere or at other times than the actual production of electricity. The total package is referred to as the 'process chain,' which consists of the following steps: * mining, refining and transport of the raw materials and uranium fuels; * construction and maintenance of the power station; * conversion of fuel or uranium into electricity; * dismantlement of the power station at the end of its life span; * processing of the resulting waste during the life of the generation plant. Mining uranium takes lots of land. Uranium is widely distributed in the earth's crust but only in minute quantities, with the exception of a few places where it has accumulated in concentrations rich enough to be economically mined as an ore. The main deposits of ore, in order of size, are in Australia, Kazakhstan, Canada, South Africa, Namibia, Brazil, the Russian Federation, the USA, and Uzbekistan. Storing nuclear wastes also takes lots of land. According to EPA, in 2000, the USA had approximately 600,000 cubic meters of different types of radioactive waste were generated, and approximately 700,000 cubic meters were in storage awaiting disposal. Radioactive wastes in the form of spent nuclear fuel (2,467 metric tons of heavy metal) and high-level waste "glass logs" (1,201 canisters of vitrified high-level waste) are in storage awaiting long-term disposal (see EPA link below). In 2003, The Energy Department has asked permission to reserve use of 308,600 acres of public land across rural Nevada to develop a railroad corridor to the proposed nuclear waste repository at Yucca Mountain, located in Nye County, which has a land area of 11,560,960 acres. Nye County is larger than the total acreage of Massachusetts, Rhode Island, New Jersey, and Delaware. Of this vast land area, only 822,711 acres (or just over seven percent of the total) is private land; the majority of the county's land is owned by the federal government. In regard to nuclear, add potential land loss to human and technical error, harsh weather and earthquakes, and potentially, to terrorism -- and the land issue becomes the least of the differentiations between the technologies. -- Scott Sklar Scott Sklar is President of The Stella Group in Washington, DC, a distributed energy marketing and policy firm. Scott, co-author of "A Consumer Guide to Solar Energy," uses solar technologies for heating and power at his home in Virginia.

5. guardian

John Hutton's latest reflections on nuclear power demonstrate how rapidly British energy policy is regressing to its default mode - dig it up and burn it (Nuclear is UK's new North Sea oil - minister, March 26). At the same time as we are promised the nuclear pipe dream, we are also set to have new coal-powered power stations without carbon capture and storage. This comes at the same time as we have fought for one of the lowest renewables targets in the EU, are languishing third from bottom in current renewables provision out of 27 EU states, and are announcing yet another microgeneration review.

The message Hutton's department seems to want to promulgate in its energy policy is to reassure everybody that no serious change is needed, that we should carry on increasing our demand for energy and that climate change isn't as urgent as some people make out. One can only conclude that the Department for Business, Enterprise and Regulatory Reform is utterly unfit for purpose and should have the title Department for Fiddling While Rome Burns.
Colin Challen MP
Lab, Morley & Rothwell

The idea of reducing global warming CO2 pollutants by nuclear stations, relying on an ever-dwindling supply of finite uranium, runs diametrically counter to government commitments to embark on a programme of renewable energy resource developments.

Renewable schemes tap into infinite sources of freely available energy that can be converted into electricity at a fraction of the cost - and far more safely - than nuclear installations and with the popular support of the electorate.

This leads one to conclude that the public is once again being deceived about the true intentions behind the government's energy policies. The nuclear option conveniently maintains control of both electricity generation and its fissionable nuclear by-products, under the authority of central government, giving future ministers the power base they need to hold sway over both civilian energy needs and military policy.

The nuclear deterrent factor is carefully kept under wraps lest the public become aware that they are being asked to subsidise future generations of Trident missile war heads under the guise of civil-energy production facilities.
Julian Rose
Whitchurch-on-Thames, Reading

Given that oil is such an environmental disaster, John Hutton couldn't have come up with a more revealing metaphor. Nuclear's problems with radiation containment, waste disposal and plant decommissioning have been well-aired.

But centralised power generation, from whatever source, is massively wasteful, with high energy loss in generation and distribution. Moreover, the way we use energy is also massively wasteful. The future lies with microrenewable generation, mediated by fuel cells, set in local networks and coupled to more efficient energy use, with end-of-life reclamation and recycling. Jobs generated in this way will outnumber unsustainable ones in constructing nuclear plants that will remain as monuments to the folly of our generation.
John Stone
Thames Ditton, Surrey

This is yet another chapter in a 50-year fantasy that nuclear power will bring untold riches. The Thorp plant at Sellafield, which has never worked properly, is to be demolished at a cost of £600m. In the 1950s nuclear electricity was going to be too cheap to meter. All of these false starts miss one vital point. Uranium is a fossil fuel. There are no uranium reserves in Britain.

Mining, refining and transporting uranium generates significant environmental impacts and greenhouse gas emissions, which need 10 years of nuclear generation to balance. As a scarce commodity, uranium prices will rise to follow oil. No one knows what to do with the waste, except make weapons of mass destruction. For 10% of the tax money spent without results on nuclear power, we could have retrofitted 100% of our housing stock to a zero-carbon standard, and saved 40% of our energy consumption. Perhaps Emperor Nero might advise?
Professor Lewis Lesley
Liverpool

6. CUS

Nuclear power is back in fashion, touted as a pain-free solution to climate change and looming energy shortages. But do its claims really add up? A new report commissioned by the Ashden Awards casts some deep shadows over nuclear’s prospects – while shedding light on the case for renewables. Author Andrew Simms sums up its findings.

Nuclear power has been promoted as the answer to both climate change and energy insecurity. It is neither. As a response to global warming, it is too slow, too expensive and too limited. And in an age of terrorist threats, it is more of a security risk than a solution.

Our research for the Ashden Awards finds no substance in claims that it has an increased role to play in a flexible, safe, secure and climate-friendly energy supply system. These, in fact, are the characteristics of renewable energy, which is abundant and cheap to harvest both in the UK and globally. Successive investigations by government and parliament have come to similar conclusions.

The UK government is committed to ‘evidence-based policy’. This should rule out a nuclear revival, since, even on the limited criteria of cost and security, nuclear loses out to renewable energy. Add in other criteria to an assessment of energy choices, and such a decision is reinforced. Whether it’s on the issue of toxic waste, the speed with which new supplies can be brought on stream, the flexibility of the technologies, or the question of, pound for pound, how many jobs are created – in each case, renewable energy beats nuclear hands down.

Why we need renewables now

There are three major reasons why a rapid uptake of renewable energy is now vital for the UK.

First, climate change means we need to drastically reduce our reliance on fossil fuels. Under the Kyoto Protocol, we’re already committed to reducing greenhouse gas emissions by 12.5% by 2010, compared with 1990 levels. Acting independently, the government has also committed itself to a 20% reduction in CO2 emissions by 2010, and a further 60% cut by 2050. Without a massive increase in renewable energy (and a major improvement in energy efficiency), these latter targets will be impossible to meet.

Secondly, one of the greatest unacknowledged threats to the UK economy is the imminent peak of global oil production, which is set to send already high oil prices much higher still, creating a severe economic shock of large but unpredictable proportions.

Thirdly, Britain’s current stock of nuclear power stations is ageing, and will progressively close over the coming two decades.

Some argue that renewable energy alone could never fill the looming ‘energy gap’ (created in part by the nuclear shut down). But our research shows that a broad combination of renewable sources, tapped into with a range of micro, small, medium and larger scale technologies, and flexibly applied, could more than meet all our needs. Better still, such an approach has the ability to create new access to power supplies for millions of people around the world who currently lack such basics as household lighting, or the ability to cook without inhaling lethal smoke.

Potential energy

The potential from renewable energy has been well charted, yet is often still underestimated. Wave power could realistically meet 15% of UK electricity demand, and tidal power an additional 6.5%. Then there’s wind power. With 40% of the total available wind power resources in Europe, the UK has theoretically enough to meet its electricity needs eight times over. Indeed, new research from Stanford University in the US shows that low-cost wind energy is much more widely available than previously thought, and alone could generate more than enough power to satisfy the world’s energy demand.

“With 40% of Europe’s total available wind power resources, the UK has theoretically enough to meet its electricity needs eight times over.”

Even given the current limiting structure of the national grid system, and the fluctuating nature of demand, a combination of offshore and onshore wind could provide up to 35% of the UK’s electricity. Which makes the government’s target of generating 20% of electricity needs through renewable power by 2020 more than achievable. The great majority of this would come from wind power.

But can public opposition be overcome? One man who spent 30 years building and installing nuclear, coal, gas and other power stations before moving to wind thinks so. Allan Moore is now chair of the British Wind Energy Association and head of renewables at National Wind Power. He argues that the current debate lacks a sense of proportion. “In the 17th century, we had 90,000 windmills in Britain. They were a part of life. What we’re looking to do now is install perhaps 4,000 turbines, making 5,000 in total. Roughly half will be onshore and half offshore. If 4,000 turbines sounds a lot, compare this to Germany, where last year alone they installed more than 2,500MW of capacity, and now have 7,000 turbines.”

While the public debates rage around the visual impact of large wind farms, the potential contribution of renewable energy from microgeneration – small-scale, localised power – has been largely overlooked. Thomas Edison had such sources in mind when he built the world’s first power plant, Pearl Street Station, in New York in 1882. He had a vision of a decentralised energy industry with dozens of companies generating and delivering power close to where it was to be used, and even putting systems in factories and people’s homes. In 1907, 59% of American electricity came from small-scale generation.

Merely hinting at the UK potential for microgeneration, there are claims that new innovations in domestic-level wind generators might affordably provide up to 80% of a household’s electricity demand. At the same time, solar thermal units can meet around half of a household’s annual hot water requirements, even in chilly Britain. Then there is further potential from roof- and ground-mounted solar photovoltaic (PV) panels, ground source heat pumps that work like a refrigerator in reverse, and, in appropriate locations, biomass generators, fuelled by tree waste or specially grown ‘energy crops’.

Microgen is climate-friendly and relatively low-cost energy, and has numerous other particular advantages. It reduces both the total supply capacity needed within networks, and the need for ‘peak provision’, which is one of the biggest planning headaches for utility managers. Since power is generated for local use, much less is lost during transmission, leading to major energy efficiency gains. (Ofgem, the gas and electricity regulator, calculates that power lost as heat on the grid costs the UK nearly $1 billion each year.) Microgen also means greater diversity in terms of power source and location, so reducing the vulnerability of the system overall. When a big power station ‘goes down’ a whole area might suffer a blackout, as happened recently in New York and in Italy. Microgen creates a broader, more secure basis of supply.

It’s also fast and flexible when it comes to installation. Units can be installed far more quickly than a large central power station, and modular systems for wind, micro hydro, solar and biomass allow potential for cost savings through scaling up. It’s far easier to achieve economies of scale by making thousands of microgeneration units, than a handful of prototype nuclear power stations. (And in some senses, every nuclear power station is a prototype, because it must adapt its security and safety measures to each unique location.)

Microgen from renewable sources also helps inoculate against price fluctuations in fossil fuels. Fossil fuels are a finite commodity whose supplies are geographically fixed. The market for them is notoriously volatile, making a nightmare for national economic planners. By contrast, microgen units can be installed where the power is actually needed – and that in turn has the potential to spur economic development at the community level.

“If 10 million consumers each installed 2kW of microgen PV or wind systems, they’d supply as much power as the UK nuclear programme.”

There are 29 million electricity customers in the UK. There is a potential for microgeneration for most of these, as the majority of households and businesses could comfortably accommodate a small-scale renewable generator of some sort. The Network for Alternative Technology and Technology Assessment, based at the Open University, has estimated that if 10 million consumers installed 2kW of microgen PV or wind power systems on their premises, they would supply as much power as the UK nuclear programme.

Though not ideal for a decentralised system, the big energy utility companies are slowly waking up to the fact that microgenerators connected to the grid can make an important and growing contribution. Currently, however, their many advantages are not matched by the sort of preferential arrangements available to other, less sustainable energies. The government should act to remove damaging distortions in the energy market by signalling a fundamental shift of public financial support, away from fossil fuels and nuclear power, and towards renewable energy and microgeneration. This should apply both to the rollout of renewable energy, and to research and development.

A whole range of incentives should now be set out to ease the path of microgen, including tax allowances for investing in renewable energy; stamp duty concessions for buildings fitted with them; and an obligation on all electricity suppliers to purchase power from microgenerators. Local authorities need to set targets for the uptake of microgen in their area, and ease their planning path by allowing them as ‘permitted developments’, on a par in the planning process with satellite dishes.

The benefits to be had are not just those of clean energy. According to the renewable energy industry, it employs 8,000 people in the UK and is set to increase dramatically, with estimates that 25,000 jobs will be created by 2020. In the US, where official attitudes to climate change are more dismissive, the number of jobs in renewables is nevertheless projected to grow to 1.3 million by 2020, with 150,000 in PV alone. In Europe, one million PV jobs have been projected by 2010; two million by 2020. Figures from the European Commission are more conservative, but still predict that 900,000 new jobs will be created in renewable energy systems by 2020. This is job creation on a serious scale.

The potential is huge: yet there is still a real danger that a resurgence of nuclear power could block its fulfilment, by distracting political attention and diverting financial support. The government’s Performance and Innovation Unit, no less, warned: “A sustained programme of investment in currently proposed nuclear power plants could adversely affect the development of smaller scale technologies.”

In order to level the economic playing field for renewables in general, and microgeneration in particular, two things are needed. First, the UK government should remove the existing direct and indirect subsidies to nuclear power that ‘featherbed’ its prospects. Secondly, financial support for renewable energy should rise to match the levels historically enjoyed by nuclear power.

In its evidence to the government’s 2002 energy review, the Carbon Trust neatly summed up the challenge. “Government funding should be focused on energy efficiency and renewables, as they have the highest long-term potential to deliver a low-carbon economy at the lowest overall cost.” We could not agree more.

This article was originally published in 'Light Emerging', a Special Supplement published by Green Futures magazine (July/August 2005), the leading source of news and debate, packed with environmental solutions, www.greenfutures.org.uk. For information on subscribing to Green Futures, call 01223 564334.

7. consciouschoice

Decades after the last nuclear power plant was built in the U.S., nuclear energy is once again being promoted as a ready to go, stop-gap to global warming.

Nuclear advocates contend that since the clock is ticking on fossil fuels, in terms of both supply and emissions, there isn’t the time nor the technology to make renewable energy a viable alternative.

But the technology has been quietly growing and improving over the last 40 years. Now more than a million households generate their own electricity with no emissions. Businesses and governments are getting into the game. Utilities and even Wall Street are giving their blessing.

People who use energy from the sun or wind to power their houses or businesses will tell you, it’s real and it’s fabulous. But without the level of subsidies that go to conventional energy sources, it’s still relatively expensive to install. That’s the rub, because once it’s in place, it produces virtually free energy. What’s missing, renewable energy advocates say, are economies of scale and subsidies for start-up costs.

There are plenty of subsidies planned for the nuclear power industry, and more are in the works. According to a plan by the Nuclear Energy Institute in Washington, 50 nuclear plants would be built in the U.S. between 2010 and 2020.

Supporters are calling it a “nuclear renaissance.”

But others such as Alfred Meyer, executive director of the Madison Chapter of Physicians for Social Responsibility, call it a “nuclear relapse.”

Meyer acknowledged that no greenhouse gases are emitted by nuclear plants in operation, but he pointed out, there are plenty of emissions in every other phase of the nuclear fuel cycle, from uranium mining and refining, to transport and storage of spent fuel. Insurance costs alone, he says, make nuclear a bad economic choice. Yet what most worries Meyer about this renewed embrace of nuclear energy is the highly toxic nature of both the process and the waste it leaves behind.

Meyer spent two weeks in Chernobyl last June with “Friends of Chernobyl U.S.” (www.focc.us.org), a group formed to deal with the psychological, health and economic impact of the disaster at the nuclear plant there in 1986.

Meyer said he was devastated by what he saw. He doesn’t buy assurances that the same thing couldn’t happen here.

“Air quality and global warming is of course important,” said Meyer. “But why take these risks if there are alternatives?”

The move toward nuclear energy is downright “crazy” when such clean, elegant solutions exist already and have been in use for decades, according to Joe Schwartz, CEO and technical editor of Home Power Magazine, a bi-monthly based in Ashland, Ore.

“Solar electric panels have no moving parts, they make electricity with no noise, no emissions,” said Schwartz. “In two to four years they recoup all the energy it took to make them.”

While solar power is still relatively expensive when compared to current average prices for electricity, wind power is becoming one of the least expensive forms of energy in the world.

At an average 5 cents per kilowatt hour, it’s competitive with conventional energy, with none of the price volatility and few external costs such as environmental clean-up.

Like solar power, wind power is relatively fast and easy to install. In Illinois, the Mendota Hills Wind Farm, about an hour west of Chicago, was built in less than six months. More are quickly going up all over the Midwest including a larger wind farm in Bloomington, Ill. that will generate 400 megawatts.

But the numbers don’t add up for John Rowe, chairman and CEO of Exelon Corporation, the parent company of Commonwealth Edison, headquartered in Chicago.

“If you’re looking for the free lunch in energy production you’ll get very hungry,” Rowe said. “To me the issue is always how do we make energy in a more acceptable way without imposing unacceptable costs on our customers … We don’t build power plants because we love them, but because we ned them to keep their lights on.”

He added that Exelon will be “mixing some wind in with the existing base of coal and nuclear and gas … [and] we can do that with reasonable economics. But we can’t bet the whole supply on greener sources, that won’t make an economic mix.”

Shwartz said he thinks that is the best possible approach.

“Renewable energy is part of the solution. We need to be realistic with our goals but we want to swing for the fence,” he said. “Even if we sold every solar panel that exists we right now we won’t replace a nuke plant, but over 20 years if production stepped up, you bet we could get rid of those plants.”

Shwartz pointed out that when energy is created 40 feet from where it is needed the process saves money by being more energy efficient.

Line losses average about seven percent nationwide, however, total energy losses in the production of electricity are about 75 percent, according to Randy Udall, Director of the Community Office for Resource Efficiency (CORE), a non-profit organization in western Colorado. “A typical power plant in this country only converts 33 percent of the energy in its fuel into electricity,” said Udall. “So, we immediately lose about 66 percent of the available energy; that plus the line losses gets us to your 75 percent figure. So it is true to say that energy losses, including line losses, are about 75 percent in the production of electricity. “Some of the newer combined cycle natural gas power plants, it is true, convert 50 percent or a bit more of the energy in the gas into electricity. But the average plant, including all the coal plants, in the U.S. is around 33 percent efficient.”

8. nukefree

NUCLEAR Energy

Global Warming
Nuclear power makes global warming worse. It is not a clean solution to the climate crisis, but instead diverts scarce resources from the green techologies that really work: renewables, conservation, and efficiency technologies that can really can solve the climate crisis while also generating wealth, jobs and economic stability.

Atomic Economics
The nuclear power industry has gone to Congress demanding loan guarantees for one basic reason: atomic reactors are not economically sound. Nobody will finance new ones without the taxpayer being forced to take the ultimate risk. Nuclear power is not a new technology. What Forbes Magazine has called "the largest managerial disaster in business history" is a proven economic failure.

Terror and Error
The terror attacks of September 11, 2001, made it clear that every atomic reactor is a pre-deployed potential weapon of radioactive mass destruction.

The first jet that flew into the World Trade Center passed one minute earlier over the Indian Point reactor complex, 45 miles to the north. There are three reactors there---two active and one inactive---plus thousands of tons of high level radioactive fuel.

Thankfully, humankind has never experienced the horrifying event of a jet plane flying into the containment dome of an active atomic reactor. The industry likes to claim that there would be no penetration. But that's wishful thinking. It has no hard data---and let's hope it never does.

The Uranium & Weapons Connection

Despite the nuclear energy industry's well-funded efforts to convince the public otherwise, uranium fuel for atomic power plants is in limited supply. Like coal, oil and gas, it will soon run out, leaving scores of giant reactors useless and abandoned.

Waste Storage and Transport
Fifty years ago, the nuclear power industry promised there would be a solution to the problem of high level radioactive waste. Today, we are no closer to managing these uniquely lethal materials than we were in 1957, when the first reactor opened.

renewable energy

A Green Revolution
Renewable energy and increased efficiency comprise the true solution to global warming.

Wind, solar, bio-fuels and other forms of renewables form a proven, immensely profitable multi-billion-dollar industry, with rapid growth on the horizon. In concert with increased efficiency, currently available green power technology can power our entire planet, while solving the global warming problem and guaranteeing our future prosperity.

Indeed, what was in 1979 viewed by many as “marginal” and “impractical,” renewables are now America's leading source of cheap, new energy supply.

Wind Power
Commercial-scale wind farms, now a $15 billion/year industry, have jumped forward as the world's cheapest and fastest-growing new energy producer.

Solar
Photovoltaic (PV) cells, which convert sunlight directly to electricity, can make buildings energy self-sufficient. New breakthroughs are allowing solar features to be integrated into roofing shingles, windows and even paint. Big desert-based power towers and trough-mirror arrays are proving increasingly profitable.

Biofuels
Soy diesel and corn-based ethanol can profitably supplant fossil fuels. Advances using easily grown perennials like switchgrass, hemp, kudzu, algae and a wide range of trees and weeds will make biofuels even cheaper and cleaner.

The Great Biofuels Debate
Skyrocketing demand for energy has carried over to bio-fuels, most importantly corn-based ethanol and soy diesel. Serious environmental objections have been raised against both of them, including the increased pressure on food prices. But is this a function of bad agricultural practices? And what sense does it make to use annual food crops for bio-fuels, when inedible perennials such as switchgrass, hemp and algae could be far cheaper and more ecologically sound? This huge debate will help define the human future.

Geothermal
Geothermal technology uses superheated steam from the Earth's core to create energy in more than 20 countries worldwide. The steady 55-degree heat of the Earth's crust also works the building of homes and offices, including large urban skyscrapers. This nature-based technology provides valuable supplemental heat in winter and base-line cooling in summer.

Power from the Waters
The ceaseless power of the oceans' waves, tides and currents is being harvested with extremely simple new technology whose profitability is advancing quickly.

Closing the Loop on Waste
Conservation and efficiency can save ten times as much energy per dollar invested as nuclear power can produce. When we tighten up our system and cut down on waste, we open the door to a green-powered Earth.

9. ezinearticles

There is quite a bit of talk about nuclear power as it is being touted as a clean reliable energy source. It is actually put on par with solutions to our power needs like solar and wind power. I beg to differ. The nuclear power industry is getting as old as I am! Nuclear plant owners are trying to see if they may be able to capitalize on these developments. They are doing retrofits and upgrades in every plant they can in order to spruce themselves up for the unwary public.

The problem as I stated earlier is the age of the nuclear plants currently in existence. Around 40 percent of U.S. nuclear power stations are over 30 years old. More than 90 percent of all plants in the U.S. are over 20 years old. Well, you might say, so what? If they are working out, then let's use them. Therein lies the rub. Nuclear power plants are built using reinforced concrete and structural steel , with concrete having the higher numbers in so far as materials used are concerned.

Over time the materials used to build a plant start to corrode and develop cracks (known as stress corrosion cracking [SCC]) because of age and exposure to radiation. If you consider steam turbines then the blade attachment areas and disc bores of low pressure turbine rotors are in danger of SCC.

The owners of some plants want to replace low pressure steam paths with higher pressure steam flow equipment. This theoretically could result in higher output. The emphasis on theoretically is mine. I have worked in the nuclear power industry as an engineer and one thing is certain, and that is nothing is certain. It is hoped that this solution will address reliability issues with these existing steam turbines.

The retrofit that most are opting for would include installing new low pressure rotors, rotating and stationary blades, inner casings and blade carriers. The scope of this type of retrofit would be large and costly. They would have to install or replace: high efficiency, integrally shrouded, reaction type blading for their front stages; longer last stage rotating blades to reduce the energy content of the steam leaving the turbine, thereby increasing turbine output; provide consistent and predictable vibration characteristics, snubbers at three quarter height will need to interconnect the last stage rotating blades and the second to last stage blades will need to be linked by integral tip shrouding; provide reduced stage leakage due to better sealing and reaction characteristics over the length of the blade; and select materials to provide erosion corrosion characteristics.

These upgrades are not all that would need to be done, and I include them here to show the complexity of this proposed fix of the aging nuclear power plants. This is not to confuse the layman but merely to show that this undertaking would be of immense scope and would cost millions of dollars. Dollars perhaps better spent pursuing alternative energy in the form of renewable energy resources.

The owners of some of these plants are saying that by the low carbon output (i.e. lower CO2 which has been shown to cause global warming) and possible gains in capacity, they could in some cases identify around 350MW of electricity increase by 2014.

I don't want to give the impression that nuclear power should be abandoned, I am a scientist and I would not make rash statements like this without some sort of research. It is simply obvious that we are already paying a very high price for electricity generated by nuclear power. The cost alone would be enough to deter some, and there is still the question of safety. Obviously we have not mastered nuclear power to the point that we can claim that it is 100 percent safe. The byproduct of nuclear power or it's waste is weapons grade plutonium. That is enough to make me question the sanity of utilizing this option. There has never been a permanent solution for the question of waste storage.

There would certainly be a decrease of carbon dioxide emissions if we pursue this course, however is that enough? We have the technology for several different course to pursue. The carbon dioxide emission problem would simply cease to exist with renewable energy resources generating our electricity. The money needed for this option is not available, but if we can spend so recklessly on nuclear power, could we not use the same funds for sustainable and renewable energy sources?

I am saddened to say that in some cases utility operators, owners of the aging nuclear plant system would not invest in installing new power transmission lines to enable more wind turbine or solar power systems. Too costly, and not part of the scope of their work. This from the people selling us our electric power. My bills have increased over the past year by 20 percent. My income certainly did not increase by anywhere near that amount.

We should at least look at this problem and lobby our elected officials to make a stand for the sake of all Americans, for the sake of the people of earth in general. The utility companies work for you and me, write to them, we are their customers. We should at least try.

Why don't we investigate wind power or solar power, there would be costs, but that is another article altogether. Just bear in mind that nuclear power is not renewable or sustainable.

I am an engineer, artist, writer, single father and a gourmet cook, I have extensive life experience covering a wide variety of topics. I have traveled extensively in the U.S. and I know many areas well. I am a teacher at times, as well as a mentor. I have written extensively about many subjects and decided I would like to try and bring about change in certain areas such as, alternative energy, single parenting and other topics that are concerns for the residents of this planet. I am well versed in the marketing of products and ideas. I want to help make the world a better place than it was when I arrived here.

Article Source: http://EzineArticles.com/?expert=Robert_L_West

Global Warming FACT! (512developing)

2008-12-10T23:37:00.000-08:00

- Human activities have caused some 500 bird species worldwide to go extinct over the past five millennia. The predominant cause of species loss is habitat destruction.

- Polar bears and hippos have joined the ranks of species threatened with extinction from climate change, unregulated hunting and other man-made dangers. More than 16,000 species of animals and plants are at risk of disappearing.

- Rainforests cover only 7% of the earth's land surface, but they contain more than half of the species on earth.

- Lightning flickers from the clouds to the ground somewhere in the United States 25 million times each year. An average of 67 people is killed by this lightning each year.

- An oak tree produces about 50,000 acorns in a good season. Only a handful actually survive in just the right conditions to grow into trees.

- Six of the 10 warmest years on record for the contiguous U.S. have occurred since 1998, part of a three decade period in which mean temperatures for the contiguous U.S. have risen at a rate near 0.6°F per decade.

- Over the course of 50 years, a single tree can generate $31,250 of oxygen, provide $62,000 worth of air pollution control, recycle $37,500 worth of water, and control $31,500 worth of soil erosion.

- The Amazon River basin contains 20% of the world's fresh water.

- Approximately 100 million people in the U.S. are breathing air that is below the federal air quality standard because of microscopic soot from power plants, diesel-burning trucks, cars and factories.

- Humans take up 83% of the earth's land surface to live on, farm, mine or fish.

Green Design Concepts (512developing)

2008-12-10T23:34:00.000-08:00

"Thinking green"

* Smaller is better: Optimize use of interior space through careful design so that the overall building size--and resource use in constructing and operating it--are kept to a minimum.

* Design an energy-efficient building: Use high levels of insulation, high-performance windows, and tight construction. In southern climates, choose glazings with low solar heat gain.

* Design buildings to use renewable energy: Passive solar heating, daylighting, and natural cooling can be incorporated cost-effectively into most buildings. Also consider solar water heating and photovoltaics--or design buildings for future solar installations.

* Optimize material use: Minimize waste by designing for standard ceiling heights and building dimensions. Avoid waste from structural over-design (use optimum-value engineering/advanced framing). Simplify building geometry.

* Design water-efficient, low-maintenance landscaping: Conventional lawns have a high impact because of water use, pesticide use, and pollution generated from mowing. Landscape with drought-resistant native plants and perennial groundcovers.

* Make it easy for occupants to recycle waste: Make provisions for storage and processing of recyclables: recycling bins near the kitchen, undersink compost receptacles, and the like.

* Look into the feasibility of graywater: Water from sinks, showers, or clothes washers (graywater) can be recycled for irrigation in some areas. If current codes prevent graywater recycling, consider designing the plumbing for easy future adaptation.

* Design for durability: To spread the environmental impacts of building over as long a period as possible, the structure must be durable. A building with a durable style ("timeless architecture") will be more likely to realize a long life.

* Design for future reuse and adaptability: Make the structure adaptable to other uses, and choose materials and components that can be reused or recycled.

* Avoid potential health hazards: radon, mold, pesticides: Follow recommended practices to minimize radon entry into the building and provide for future mitigation if necessary. Provide detailing that will avoid moisture problems, which could cause mold and mildew growth. Design insect-resistant detailing that will require minimal use of pesticides.

SITING & LAND USE

* Renovate older buildings: Conscientiously renovating existing buildings is the most sustainable construction.

* Create community: Development patterns can either inhibit or contribute to the establishment of strong communities and neighborhoods. Creation of cohesive communities should be a high priority.

* Encourage in-fill and mixed-use development: In-fill development that increases density is inherently better than building on undeveloped (greenfield) sites. Mixed-use development, in which residential and commercial uses are intermingled, can reduce automobile use and help to create healthy communities.

* Minimize automobile dependence: Locate buildings to provide access to public transportation, bicycle paths, and walking access to basic services. Commuting can also be reduced by working at home--consider home office needs with layout and wiring.

* Value site resources: Early in the siting process carry out a careful site evaluation: solar access, soils, vegetation, water resources, important natural areas, etc., and let this information guide the design.

* Locate buildings to minimize environmental impact: Cluster buildings or build attached units to preserve open space and wildlife habitats, avoid especially sensitive areas including wetlands, and keep roads and service lines short. Leave the most pristine areas untouched, and look for areas that have been previously damaged to build on. Seek to restore damaged ecosystems.

* Provide responsible on-site water management: Design landscapes to absorb rainwater runoff (stormwater) rather than having to carry it off-site in storm sewers. In arid areas, rooftop water catchment systems should be considered for collecting rainwater and using it for landscape irrigation.

* Situate buildings to benefit from existing vegetation: Trees on the east and west sides of a building can dramatically reduce cooling loads. Hedge rows and shrubbery can block cold winter winds or help channel cool summer breezes into buildings.

MATERIALS

* Avoid ozone-depleting chemicals in mechanical equipment and insulation: CFCs have been phased out, but their primary replacements--HCFCs--also damage the ozone layer and should be avoided where possible. Avoid foam insulation made with HCFCs. Reclaim CFCs when servicing or disposing of equipment.

* Use durable products and materials: Because manufacturing is very energy-intensive, a product that lasts longer or requires less maintenance usually saves energy. Durable products also contribute less to our solid waste problems.

* Choose low-maintenance building materials: Where possible, select building materials that will require little maintenance (painting, retreatment, waterproofing, etc.), or whose maintenance will have minimal environmental impact.

* Choose building materials with low embodied energy: Heavily processed or manufactured products and materials are usually more energy intensive. As long as durability and performance will not be sacrificed, choose low-embodied-energy materials.

* Buy locally produced building materials: Transportation is costly in both energy use and pollution generation. Look for locally produced materials. Local hardwoods, for example, are preferable to tropical woods.

* Use building products made from recycled materials: Building products made from recycled materials reduce solid waste problems, cut energy consumption in manufacturing, and save on natural resource use. A few examples of materials with recycled content are cellulose insulation, Homasote®, Thermo-ply®, floor tile made from ground glass, and recycled plastic lumber.

* Use salvaged building materials when possible: Reduce landfill pressure and save natural resources by using salvaged materials: lumber, millwork, certain plumbing fixtures, and hardware, for example. Make sure these materials are safe (test for lead paint and asbestos), and don't sacrifice energy efficiency or water efficiency by reusing old windows or toilets.

* Seek responsible wood supplies: Use lumber from independently certified well-managed forests. Avoid lumber products produced from old-growth timber unless they are certified. Engineered wood can be substituted for old-growth Douglas fir, for example. Don't buy tropical hardwoods unless the seller can document that the wood comes from well-managed forests.

* Avoid materials that will offgas pollutants: Solvent-based finishes, adhesives, carpeting, particleboard, and many other building products release formaldehyde and volatile organic compounds (VOCs) into the air. These chemicals can affect workers' and occupants' health as well as contribute to smog and ground-level ozone pollution outside.

* Minimize use of pressure-treated lumber: Use detailing that will prevent soil contact and rot. Where possible, use alternatives such as recycled plastic lumber. Take measures to protect workers when cutting and handling pressure-treated wood. Scraps should never be incinerated.

* Minimize packaging waste: Avoid excessive packaging, such as plastic-wrapped plumbing fixtures or fasteners that aren't available in bulk. Tell your supplier why you are avoiding over-packaged products. Keep in mind, however, that some products must be carefully packaged to prevent damage--and resulting waste.

EQUIPMENT

* Install high-efficiency heating and cooling equipment: Well-designed high-efficiency furnaces, boilers, and air conditioners (and distribution systems) not only save the building occupants money, but also produce less pollution during operation. Install equipment with minimal risk of combustion gas spillage, such as sealed-combustion appliances.

* Install high-efficiency lights and appliances: Fluorescent lighting has improved dramatically in recent years and is now suitable for homes. High-efficiency appliances offer both economic and environmental advantages over their conventional counterparts.

* Install water-efficient equipment: Water-conserving toilets, showerheads, and faucet aerators not only reduce water use, they also reduce demand on septic systems or sewage treatment plants. Reducing hot water use also saves energy.

* Install mechanical ventilation equipment: Mechanical ventilation is usually required to ensure safe, healthy indoor air. Heat recovery ventilators should be considered in cold climates because of energy savings, but simpler, less expensive exhaust-only ventilation systems are also adequate.

JOB SITE & BUSINESS

* Protect trees and topsoil during sitework: Protect trees from damage during construction by fencing off the "drip line" around them and avoiding major changes to surface grade.

* Avoid use of pesticides and other chemicals that may leach into the groundwater: Look into less toxic termite treatments, and keep exposed frost walls free from obstructions to discourage insects. When backfilling a foundation or grading around a house, do not bury any construction debris.

* Minimize job-site waste: Centralize cutting operations to reduce waste and simplify sorting. Set up clearly marked bins for different types of usable waste (wood scraps for kindling, sawdust for compost, etc.). Find out where different materials can be taken for recycling, and educate your crew about recycling procedures. Donate salvaged materials to low-income housing projects, theater groups, etc.

* Make your business operations more environmentally responsible: Make your office as energy efficient as possible, purchase energy-efficient vehicles, arrange carpools to job sites, and schedule site visits and errands to minimize unnecessary driving. In your office, purchase recycled office paper and supplies, recycle office paper, use coffee mugs instead of disposable cups. On the job, recycle beverage containers.

* Make education a part of your daily practice: Use the design and construction process to educate clients, employees, subcontractors, and the general public about environmental impacts of buildings and how these impacts can be minimized. From our environmental friends at building-green.com

Ten Earth-Friendly Things (512developing)

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Use efficient lighting: Compact fluorescent lights (CFLs) use 70% less energy and last 10 times longer than standard bulbs.

Adjust your thermostat: Set your programmable thermostat two degrees warmer than usual in summer and two degrees cooler in winter—then watch your energy use drop.

Reduce phantom load: Home electronics draw 40% of the electricty they use while turned off—unplug chargers and home entertainment systems when not in use.

Conserve water in- and outdoors: Treating and pumping water takes a huge amount of electricity—saving water saves money and power too.

Plant a tree at home: Carefully chosen and planted trees soak up CO₂ and shade your home for lower summer utility bills.

Drive less: Walk, ride a bike, carpool, take the bus, and combine trips when possible.

Keep your car in tune: A poorly tuned engine wastes 10 to 20% of its fuel; a clogged air filter risks a 10% increase in fuel consumption; and low tire pressure means another 5% drop in efficiency.

Reduce, reuse, recycle: Create less waste by reusing or recycling items.

Buy local: Most food is shipped more than 1,500 miles to get to your plate—locally grown food saves fuel and tastes better.

Talk: Raise awareness among your friends, family, and coworkers, and tell government leaders you want meaningful climate protection planning and policies now.

8 types of Renewable energy (512developing)

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1. Bio-fuel & Biomass

Biomass is derived from plant material and animal wastes. It can be used to generate electricity and or heat and to produce transport fuel.

A very wide range of biomass can be used for energy purposes. Examples include agricultural wastes, eg straw and other crop residues; crops grown specifically for energy production, eg willow, miscanthus, oil seed rape and wastes from a range of sources including food production. The nature of the fuel will determine the way that energy can best be recovered from it.

Dry biomass fuels

The most straightforward way to recover energy from dry biomass fuels is by combustion to provide heating or hot water. These types of applications range in size from simple log fires and stoves, to sophisticated wood or straw fuelled boiler systems, usually with automatic fuel handling and control systems.

CHP is becoming an increasingly attractive option for biomass plant, offering a reliable low-cost heat source for industrial or commercial uses (such as a district heating system for a small community), together with electricity that can be sold to the local grid. Forest residues, industrial wood wastes and a range of agricultural wastes are often readily available as fuel for CHP plant. However, energy crops, such as wood coppice (willow or poplar in cooler climates, wattle and eucalyptus in warmer climates), or perennial grasses such as miscanthus, are becoming increasingly important. These may be grown specifically for use as a fuel, and can provide long-term secure resources. Biomass fuels are increasingly being used with advanced conversion technologies, such as gasification systems, which may offer superior efficiencies compared with conventional power generation. Gasification is a thermochemical process in which biomass is heated with little or no oxygen present to produce a low-energy gas The composition of the gas will depend on the nature of the gasification process used. The gas can then be used to fuel a gas turbine or a combustion engine to generate electricity.

Wet wastes

Cattle, pigs and poultry all produce slurries that can be used to produce biogas. The slurries can be fermented in an anaerobic digester to produce a gas that is mainly methane and carbon dioxide. The gas can be used in gas engines to generate electricity or in boilers to provide process heat or space heating. Some 40-60% of the organic matter present in the slurry is converted into biogas. After maturation, the remainder provides a stabilized residue that can be used as a soil conditioner.

2. Distributed / Embedded Generation

The electricity supply network in the U.S. is tailored to deliver power flows from large fossil and nuclear plant, down through progressively lower voltage levels to reach business and domestic customers.

The vast majority of renewable power plants are small in comparison with conventional plant and they are connected to the lower voltage distribution grid rather than the high voltage transmission grid. The term for this form of generation is "embedded" or "distributed generation".

There is a great deal of work going on to modify the U.S. Electricity Distribution and Transmission networks to accommodate the increased amount of embedded generation required to meet the country's demand

3. Energy from waste

Wastes represent an increasingly important fuel source. Using wastes as fuel can have important environmental benefits. It can provide a safe and cost-effective disposal options for wastes that could otherwise present significant disposal problems. It can help reduce CO2 emissions, through displacement of fossil fuels. Methane is 23 times more damaging than CO2 for global warming. If biodegradable waste is diverted from landfill methane emissions can be avoided.

Any energy that is recovered from biological wastes can be regarded as renewable energy. It comes from plant material (either directly, or in the case of animal wastes, paper or card, indirectly). As plants grow they absorb carbon dioxide from the atmosphere. When this biomass material is used as a fuel, the carbon dioxide is returned to the atmosphere in a "carbon neutral" cycle. If biomass is used to displace fossil fuels instead of being left to decompose naturally, it will actually help to limit the emission of carbon dioxide and methane into the air.

There are many ways of combining waste disposal with energy recovery. A number of well established technologies are available for generating heat or power from wastes. There are also new technological developments, especially in power generation, which have the potential to increase the efficiency of energy recovery.

Recovering energy from wastes from municipal or industrial sources can turn the problem of waste disposal into an opportunity for generating income from heat or power sales. The safe and cost-effective disposal of these wastes is becoming increasingly important worldwide, especially with the demand for higher environmental standards of waste disposal and the pressure on entities to minimize the quantities of waste generated and disposed to land.

The technology

A very wide range of municipal or industrial wastes may be used as fuel. The nature of the waste and the waste disposal method will determine the way that energy can be recovered. Dry household, commercial or industrial wastes can either be burned (combusted) as raw waste, or they may first undergo some sorting or processing to remove waste components that can be recycled separately.

Combustion with energy recovery

Waste combustion with energy recovery is an established way to dispose of wastes. It decreases the volume of the waste and allows for recovery of metals and other potentially recyclable fractions. After further basic treatment, most of the remaining residue can be combined with other materials and used as an aggregate material. Any residue that is landfilled is biologically inactive and does not generate potentially harmful emissions.

The heat recovered from these plants can be used to generate electricity, or can be used for industrial heat applications. The size of energy from waste plant is designed to meet the waste disposal needs of the community, taking into account the potential for waste minimization and recycling. Plants that generate electricity can typically process a large amount per year, and from this they can generate huge amounts of electricity. Power is produced from these wastes by using the steam raised in the combustion process to drive a steam turbine to generate electricity, in a similar manner to a conventional coal fired power station.

Combined heat and power (CHP) is an attractive option where there is a market for the heat . This could be a factory or district heating system for a small community.

Advanced thermal technologies

Where the waste stream is of a uniform nature, for example if it has been processed into a homogenous fuel, it is better suited to the more "advanced technologies", such as gasification or pyrolysis. Wastes that are not uniform in composition, for example municipal wastes, are less suited to treatment by advanced technology, although the technology is rapidly developing to handle more challenging wastes.

Gasification

Gasification is one of the newer technologies that is increasingly being used for waste disposal. It is a thermo-chemical process in which biomass is heated, in an oxygen deficient atmosphere to produce a low-energy gas containing hydrogen, carbon monoxide and methane. The gas can then be used as a fuel in a turbine or combustion engine to generate electricity. Gasifiers fuelled by fossil sources such as coal have been operating successfully for many years, but they are now increasingly being developed to accept more mixed fuels, including wastes. New gas clean-up technology ensures that the resulting gas is suitable to be burnt in a variety of gas engines, with a very favorable emissions profile. Gasifiers operate at a smaller scale than incineration plant, and can also be provided in modular form to suit a range of different scales of operation.

Pyrolysis

Pyrolysis is another emerging technology, sharing many of the characteristics of gasification. With gasification partial oxidation of the waste occurs, whilst with pyrolysis the objective is to heat the waste in the complete absence of oxygen. Gas, olefin liquid and char are produced in various quantities. The gas and oil can be processed, stored and transported, if necessary and combusted in an engine, gas turbine or boiler. Char can be recovered from the residue and used as a fuel, or the residue passed to a gasifier and the char gasifed.

Strict environmental standards now apply in all U.S. states governing the emissions from energy from waste plant, particularly of heavy metals, furans and dioxins. All energy from waste plant must now meet these standards, which can be achieved through the installation of extensive state-of-the-art gas cleaning systems.

4. Water (Hydro, Tidal, Wave)

Hydro power is produced when the kinetic energy of flowing water, is converted into electricity by a turbine connected to an electricity generator.

Hydropower can be exploited at various different scales. Large-scale typically means massive amounts of grid-connected generating capacity and is usually associated with a dam and a storage reservoir. There are many large schemes in the U.S, which were built during the late 1900s. The potential for identifying new large-scale schemes is now more limited, not only because there are fewer commercially attractive sites still available, but also because of environmental constraints.

Schemes of less amounts now offer a greater opportunity for providing a reliable, flexible, and cost-competitive power source with minimal environmental impacts. These small-scale schemes are making an increasing contribution towards new renewable energy installations in many regions of the world, especially in rural or remote regions where other conventional sources of power are less readily available. Small scale schemes can be associated with a dam and storage reservoir or can be located in a moving stream ("run of river").

Tidal Power

Tidal power can use either conventional or new technology to extract energy from a tidal stream. It is usually deployed in areas where there is a high tidal range. Typically a barrage with turbines is built across an estuary or a bay. As the tide rises, it creates a height differential between the inner and outer walls of the barrage. Water can then flow through the turbines and drive generators. Some tidal barrages operate on both the rising and falling tide, but others, particularly estuarine barrages, are designed to operate purely on the falling tide.

It is also possible to make use of the tidal flow that occurs between headlands and islands or in and out of estuaries. It is this application that is the focus of much research and development, and new products for this purpose are now being commercialized. These “in-flow” tidal turbines can be arranged singly or in arrays, allowing a range of power outputs to be produced.

Wave Power

The power of the waves is readily visible on nearly every ocean shore in the world. There has been much research to harness the power of these waves, and various machines have now been developed. These fall broadly into three categories:

Machines which channel waves into constricted chambers. As the waves flow in and out of the chamber, they force air in and out of the chamber. These airflows are in turn channeled through a specialized turbine, which is used to drive a generator. This type of machine is principally designed for use on or near the shore, or for incorporation into breakwaters. Commercially, this kind of machine is the most advanced and is particularly advantageous when incorporated into coastal protection.

Fixed or semi-fixed machines which utilize the pressure differential in the water that occurs at a submerged point as the wave passes over that point. The pressure differential is used by a variety of means to cause a fluid to flow in a circuit, which is then used to drive a turbine and generator.
Machines which utilize their buoyancy to cause movement in a part of the device as it moves up and down in the wave. The movement is used either directly or indirectly to drive a generator.

5. Biogas

Biogas is a mixture comprising mainly methane and carbon dioxide. It is produced when organic matter decomposes in the abscence of oxygen. This can take place in a landfill site to give landfill gas or in an anaerobic digester to give biogas. Sewage gas is biogas produced by the digestion of sewage sludge.

Landfill gas

Landfill gas is a mixture comprising mainly methane and carbon dioxide, formed when biodegradable wastes break down within a landfill as a result of anaerobic microbiological action. The biogas can be collected by drilling wells into the waste and extracting it as it is formed. It can then be used in an engine or turbine for power generation, or used to provide heat for industrial processes situated near the landfill site, such as in a brickworks. Landfill sites can generate commercial quantities of landfill gas for up to 30 years after wastes have been deposited. Recovering this gas and using it as a fuel not only ensures the continued safety of the site after landfilling has finished, but also provides a significant long term income from power and/or heat sales.

Anaerobic digestion

The biological processes that take place in a landfill site can be harnessed in a specially designed vessel known as an anaerobic digester to accelerate the decomposition of wastes. Anaerobic digestion is typically used on wet wastes, such as sewage sludge or animal slurries but the biodegradable fraction of municipal wastes can be added to wetter wastes to increase the biogas output.

6. Fuel Cell / Hydrogen / Batteries

With Fossil Fuels projected to run out within the next century, the world is in need of a permanent replacement fuel. In addition, pollution is becoming an ever-increasing problem. What the world needs is a non-polluting inexhaustible fuel supply. Hydrogen encompasses approximately 70 % of the mass of the universe. When burned in air, or used within a Fuel Cell, water is the only waste product. These factors combine to present Hydrogen as the ultimate long-term global energy solution...

7. Solar

Photovoltaics

The sun’s energy can be converted directly into electricity using photovoltaic cells. PV cells can be used for applications as small as watches and calculators, to large grid-connected arrays of panels. The great attraction of PV technology is that it delivers electricity at the point of use, for example panels can be integrated into buildings to supply the buildings themselves.

In areas where grid connection or other forms of generation are too expensive or not feasible, PV can be very cost-effective. This may be in remote locations, but could also be in a city centre where grid connection may be impractical. For example it can be cheaper to power parking meters with solar energy than with power from the grid.

PV materials are usually solid-state semiconductors. various forms are used:-
mono-crystalline silicon (crystalline)
Poly-crystalline silicon (crystalline)
amorphous silicon (thin film)
cadmium telluride (thin film).

Active solar thermal

Active solar heating systems convert solar radiation into heat which can be used directly. In the UK uses are primarily domestic water heating and other low temperature heating applications such as swimming pools. In hotter climates a wider range of applications is possible, including electricity generation.

Domestic water heating schemes consist of solar collectors, (usually) a preheat tank, pump, control unit, connecting pipes, the normal hot water tank, and backup heat source such as gas or electric immersion heater. The collectors are mounted on the roof and heat the water tank via a fluid circulated between the collectors and the tank. The overall area of the panels is typically 3-4 square metres.

A plane inclined at about 30 degrees, facing due south ranges from around 900 KWh/m2 per year in the North of Scotland to around 1,250 kWh/m2 in the South West of England.

The optimum angle for a south facing collector is 0.9 multiplied by the latitude + 29°. This maximises winter collection and reduces over-production in the summer. The optimum angle of tilt for the spring and autumn is the latitude minus 2.5°. The optimum angle for summer is 52.5° less than the winter angle.

ENERGY FROM THE SUN

The sun has produced energy for billions of years. Solar energy is the sun’s rays (solar radiation) that reach the earth.

Solar energy can be converted into other forms of energy, such as heat and electricity. In the 1830s, the British astronomer John Herschel used a solar thermal collector box (a device that absorbs sunlight to collect heat) to cook food during an expedition to Africa. Today, people use the sun's energy for lots of things.

Solar energy can be converted to thermal (or heat) energy and used to:
Heat water – for use in homes, buildings, or swimming pools.
Heat spaces – inside greenhouses, homes, and other buildings.
Solar energy can be converted to electricity in two ways:

Photovoltaic (PV devices) or “solar cells” – change sunlight directly into electricity. PV systems are often used in remote locations that are not connected to the electric grid. They are also used to power watches, calculators, and lighted road signs.

Solar Power Plants - indirectly generate electricity when the heat from solar thermal collectors is used to heat a fluid which produces steam that is used to power generator. Out of the 15 known solar electric generating units operating in the United States at the end of 2006, 10 of these are in California, and 5 in Arizona. No statistics are being collected on solar plants that produce less than 1 megawatt of electricity, so there may be smaller solar plants in a number of other states.

The major disadvantages of solar energy are:

The amount of sunlight that arrives at the earth's surface is not constant. It depends on location, time of day, time of year, and weather conditions.

Because the sun doesn't deliver that much energy to any one place at any one time, a large surface area is required to collect the energy at a useful rate.

PHOTOVOLTAIC ENERGY

Photovoltaic energy is the conversion of sunlight into electricity. A photovoltaic cell, commonly called a solar cell or PV, is the technology used to convert solar energy directly into electrical power. A photovoltaic cell is a nonmechanical device usually made from silicon alloys.

Sunlight is composed of photons, or particles of solar energy. These photons contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons provide energy to generate electricity. When enough sunlight (energy) is absorbed by the material (a semiconductor), electrons are dislodged from the material's atoms. Special treatment of the material surface during manufacturing makes the front surface of the cell more receptive to free electrons, so the electrons naturally migrate to the surface.

When the electrons leave their position, holes are formed. When many electrons, each carrying a negative charge, travel toward the front surface of the cell, the resulting imbalance of charge between the cell's front and back surfaces creates a voltage potential like the negative and positive terminals of a battery. When the two surfaces are connected through an external load, electricity flows.
The photovoltaic cell is the basic building block of a photovoltaic system. Individual cells can vary in size from about 1 centimeter (1/2 inch) to about 10 centimeter (4 inches) across. However, one cell only produces 1 or 2 watts, which isn't enough power for most applications. To increase power output, cells are electrically connected into a packaged weather-tight module. Modules can be further connected to form an array. The term array refers to the entire generating plant, whether it is made up of one or several thousand modules. The number of modules connected together in an array depends on the amount of power output needed.

The performance of a photovoltaic array is dependent upon sunlight. Climate conditions (e.g., clouds, fog) have a significant effect on the amount of solar energy received by a photovoltaic array and, in turn, its performance. Most current technology photovoltaic modules are about 10 percent efficient in converting sunlight. Further research is being conducted to raise this efficiency to 20 percent.

The photovoltaic cell was discovered in 1954 by Bell Telephone researchers examining the sensitivity of a properly prepared silicon wafer to sunlight. Beginning in the late 1950s, photovoltaic cells were used to power U.S. space satellites (learn more about the history of photovaltaic cells). The success of PV in space generated commercial applications for this technology. The simplest photovoltaic systems power many of the small calculators and wrist watches used everyday. More complicated systems provide electricity to pump water, power communications equipment, and even provide electricity to our homes.

Some advantages of photovoltaic systems are:

Conversion from sunlight to electricity is direct, so that bulky mechanical generator systems are unnecessary.

PV arrays can be installed quickly and in any size required or allowed.

The environmental impact is minimal, requiring no water for system cooling and generating no by-products.

Photovoltaic cells, like batteries, generate direct current (DC) which is generally used for small loads (electronic equipment). When DC from photovoltaic cells is used for commercial applications or sold to electric utilities using the electric grid, it must be converted to alternating current (AC) using inverters, solid state devices that convert DC power to AC.

Historically, PV has been used at remote sites to provide electricity. In the future PV arrays may be located at sites that are also connected to the electric grid enhancing the reliability of the distribution system.

SOLAR THERMAL HEAT

Solar thermal(heat) energy is often used for heating swimming pools, heating water used in homes, and space heating of buildings. Solar space heating systems can be classified as passive or active.

Passive space heating is what happens to your car on a hot summer day. In buildings, the air is circulated past a solar heat surface(s) and through the building by convection (i.e. less dense warm air tends to rise while more dense cooler air moves downward) . No mechanical equipment is needed for passive solar heating.

Active heating systems require a collector to absorb and collect solar radiation. Fans or pumps are used to circulate the heated air or heat absorbing fluid. Active systems often include some type of energy storage system.

Solar collectors can be either nonconcentrating or concentrating.

1) Nonconcentrating collectors – have a collector area (i.e. the area that intercepts the solar radiation) that is the same as the absorber area (i.e., the area absorbing the radiation). Flat-plate collectors are the most common and are used when temperatures below about 200o degrees F are sufficient, such as for space heating.

2) Concentrating collectors – where the area intercepting the solar radiation is greater, sometimes hundreds of times greater, than the absorber area.

SOLAR THERMAL POWER PLANTS

Solar thermal power plants use the sun's rays to heat a fluid, from which heat transfer systems may be used to produce steam. The steam, in turn, is converted into mechanical energy in a turbine and into electricity from a conventional generator coupled to the turbine. Solar thermal power generation works essentially the same as generation from fossil fuels except that instead of using steam produced from the combustion of fossil fuels, the steam is produced by the heat collected from sunlight. Solar thermal technologies use concentrator systems due to the high temperatures needed to heat the fluid. The three main types of solar-thermal power systems are:

PARABOLIC TROUGHS

The parabolic trough is used in the largest solar power facility in the world located in the Mojave Desert at Kramer Junction, California. This facility has operated since the 1980’s and accounts for the majority of solar electricity produced by the electric power sector today.

A parabolic trough collector has a linear parabolic-shaped reflector that focuses the sun's radiation on a linear receiver located at the focus of the parabola. The collector tracks the sun along one axis from east to west during the day to ensure that the sun is continuously focused on the receiver. Because of its parabolic shape, a trough can focus the sun at 30 to 100 times its normal intensity (concentration ratio) on a receiver pipe located along the focal line of the trough, achieving operating temperatures over 400 degrees Celsius.

A collector field consists of a large field of single-axis tracking parabolic trough collectors. The solar field is modular in nature and is composed of many parallel rows of solar collectors aligned on a north-south horizontal axis. A working (heat transfer) fluid is heated as it circulates through the receivers and returns to a series of heat exchangers at a central location where the fluid is used to generate high-pressure superheated steam. The steam is then fed to a conventional steam turbine/generator to produce electricity. After the working fluid passes through the heat exchangers, the cooled fluid is recirculated through the solar field. The plant is usually designed to operate at full rated power using solar energy alone, given sufficient solar energy. However, all plants are hybrid solar/fossil plants that have a fossil-fired capability that can be used to supplement the solar output during periods of low solar energy.

SOLAR DISH

A solar dish/engine system utilizes concentrating solar collectors that track the sun on two axes, concentrating the energy at the focal point of the dish because it is always pointed at the sun. The solar dish's concentration ratio is much higher that the solar trough, typically over 2,000, with a working fluid temperature over 750oC. The power-generating equipment used with a solar dish can be mounted at the focal point of the dish, making it well suited for remote operations or, as with the solar trough, the energy may be collected from a number of installations and converted to electricity at a central point. The engine in a solar dish/engine system converts heat to mechanical power by compressing the working fluid when it is cold, heating the compressed working fluid, and then expanding the fluid through a turbine or with a piston to produce work. The engine is coupled to an electric generator to convert the mechanical power to electric power.

SOLAR POWER TOWER

A solar power tower or central receiver generates electricity from sunlight by focusing concentrated solar energy on a tower-mounted heat exchanger (receiver). This system uses hundreds to thousands of flat sun-tracking mirrors called heliostats to reflect and concentrate the sun's energy onto a central receiver tower. The energy can be concentrated as much as 1,500 times that of the energy coming in from the sun. Energy losses from thermal-energy transport are minimized as solar energy is being directly transferred by reflection from the heliostats to a single receiver, rather than being moved through a transfer medium to one central location, as with parabolic troughs. Power towers must be large to be economical. This is a promising technology for large-scale grid-connected power plants. Though power towers are in the early stages of development compared with parabolic trough technology, a number of test facilities have been constructed around the world.

The U.S. Department of Energy along with a number of electric utilities built and operated a demonstration solar power tower near Barstow, California, during the 1980's and 1990's. Learn more about the history of solar power in the Solar Timeline.

SOLAR ENERGY AND THE ENVIRONMENT

Solar energy is free, and its supplies are unlimited. Using solar energy produces no air or water pollution but does have some indirect impacts on the environment. For example, manufacturing the photovoltaic cells used to convert sunlight into electricity, consumes silicon and produces some waste products. In addition, large solar thermal farms can also harm desert ecosystems if not properly managed.

8. Wind

Wind energy has been harnessed for over 6000 years, first for powering boats, windmills and wind pumps, and now for generating electricity. Modern wind equipment ranges from small water pumps and chargers (used to charge batteries at remote locations) to large multi-megawatt wind turbines arranged in wind farms that supply power to the electricity grid.

World-wide, there over 25,000MW of installed capacity, mostly in Europe and the USA.

Wind power equipment has been developed to provide a range of power outputs, from under 100W up to 3MW. The overall reliability of wind turbines is high - 97-99% availability is standard for modern turbines - and modern machines are designed to have a useful life of about 25 years. Turbines can have fixed or variable speed rotors, can be pitch or stall regulated, or in the case of small turbines can have furling rotor blades. When used for electricity generation, turbines can generate either direct or alternating current. The flexibility of design of individual turbine components means that machines can be matched to areas with high, medium or low average wind speeds, from the Arctic to the Sahara, and from mountain tops to locations out to sea.

Within the design parameters necessary for conditions at any individual site, the size of turbine required will depend on the type of application:

Large-scale, grid-connected electricity generation
This requires a number of large turbines grouped together on one site to form a wind farm or wind park, either on- or off-shore. The power from the individual turbines is aggregated at a central point before it is fed through a power line to the point where it connects with the national grid. It usually passes through a transformer at the central point to match the voltage to that of the grid. The central point usually doubles as a command point, where computerised equipment can be installed to allow the remote control of the wind farm. This is particularly important for remote and off-shore wind farms, where adverse weather may prevent access for long periods of time.

Small-scale, grid-connected electricity generation
Where electricity grids are unable to accommodate large amounts of generation, typically in remote areas, it is still possible to deploy individual turbines or small clusters of turbines of varying sizes. Frequently the grids in these areas are at relatively low voltage in which case the installations are designed to connect directly into the grid with little or no additional voltage transformation. Where the grid is an isolated grid (not connected to the main national or regional grid), the wind turbines are usually run in conjunction with another form of generation, typically diesel (see hybrid systems below).

Stand-alone generation
Applications for stand alone wind power are more varied. They may be as small as a charger used to charge the batteries on an ocean-going yacht, or megawatt-size turbines used for powering a desalination plant on an arid coastline. The use of solitary wind pumps feeding water tanks has been a familiar sight in much of the world for over 150 years.

Hybrid Systems
Wind power is also very suitable for incorporation into hybrid systems. These offer flexibility, because they can provide power even when the wind is not blowing. Wind-diesel combinations are common, but more recent developments include wind-photovoltaic units, a hybrid option which offers power generation from 100% renewable sources.

ENERGY FROM WIND

Wind is simple air in motion. It is caused by the uneven heating of the earth’s surface by the sun. Since the earth’s surface is made of very different types of land and water, it absorbs the sun’s heat at different rates.

During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and rises, and the heavier, cooler air rushes in to take its place, creating winds. At night, the winds are reversed because the air cools more rapidly over land than over water.

In the same way, the large atmospheric winds that circle the earth are created because the land near the earth's equator is heated more by the sun than the land near the North and South Poles.

Today, wind energy is mainly used to generate electricity. Wind is called a renewable energy source because the wind will blow as long as the sun shines.
The History of Wind

Since ancient times, people have harnessed the winds energy. Over 5,000 years ago, the ancient Egyptians used wind to sail ships on the Nile River. Later, people built windmills to grind wheat and other grains. The earliest known windmills were in Persia (Iran). These early windmills looked like large paddle wheels. Centuries later, the people of Holland improved the basic design of the windmill. They gave it propeller-type blades, still made with sails. Holland is famous for its windmills.

American colonists used windmills to grind wheat and corn, to pump water, and to cut wood at sawmills. As late as the 1920s, Americans used small windmills to generate electricity in rural areas without electric service. When power lines began to transport electricity to rural areas in the 1930s, local windmills were used less and less, though they can still be seen on some Western ranches.

The oil shortages of the 1970s changed the energy picture for the country and the world. It created an interest in alternative energy sources, paving the way for the re-entry of the windmill to generate electricity. In the early 1980s wind energy really took off in California, partly because of state policies that encouraged renewable energy sources. Support for wind development has since spread to other states, but California still produces more than twice as much wind energy as any other state.

The first offshore wind park in the United States is planned for an area off the coast of Cape Cod, Massachusetts (read an article about the Cape Cod Wind Project).

HOW WIND MACHINES WORK

Like old fashioned windmills, today’s wind machines use blades to collect the wind’s kinetic energy. Windmills work because they slow down the speed of the wind. The wind flows over the airfoil shaped blades causing lift, like the effect on airplane wings, causing them to turn. The blades are connected to a drive shaft that turns an electric generator to produce electricity.

With the new wind machines, there is still the problem of what to do when the wind isn’t blowing. At those times, other types of power plants must be used to make electricity.

TYPES OF WIND MACHINES

There are two types of wind machines (turbines) used today based on the direction of the rotating shaft (axis): horizontal–axis wind machines and vertical-axis wind machines. The size of wind machines varies widely. Small turbines used to power a single home or business may have a capacity of less than 100 kilowatts. Some large commercial sized turbines may have a capacity of 5 million watts, or 5 megawatts. Larger turbines are often grouped together into wind farms that provide power to the electrical grid.

Horizontal-axis

Most wind machines being used today are the horizontal-axis type. Horizontal-axis wind machines have blades like airplane propellers. A typical horizontal wind machine stands as tall as a 20-story building and has three blades that span 200 feet across. The largest wind machines in the world have blades longer than a football field! Wind machines stand tall and wide to capture more wind.

Vertical-axis

Vertical–axis wind machines have blades that go from top to bottom and the most common type (Darrieus wind turbine) looks like a giant two-bladed egg beaters. The type of vertical wind machine typically stands 100 feet tall and 50 feet wide. Vertical-axis wind machines make up only a very small percent of the wind machines used today.

The Wind Amplified Rotor Platform (WARP) is a different kind of wind system that is designed to be more efficient and use less land than wind machines in use today. The WARP does not use large blades; instead, it looks like a stack of wheel rims. Each module has a pair of small, high capacity turbines mounted to both of its concave wind amplifier module channel surfaces. The concave surfaces channel wind toward the turbines, amplifying wind speeds by 50 percent or more. Eneco, the company that designed WARP, plans to market the technology to power offshore oil platforms and wireless telecommunications systems.

WIND POWER PLANTS

Wind power plants, or wind farms as they are sometimes called, are clusters of wind machines used to produce electricity. A wind farm usually has dozens of wind machines scattered over a large area. The world's largest wind farm, the Horse Hollow Wind Energy Center in Texas, has 421 wind turbines that generate enough electricity to power 220,000 homes per year.

Unlike power plants, many wind plants are not owned by public utility companies. Instead they are owned and operated by business people who sell the electricity produced on the wind farm to electric utilities. These private companies are known as Independent Power Producers.

Operating a wind power plant is not as simple as just building a windmill in a windy place. Wind plant owners must carefully plan where to locate their machines. One important thing to consider is how fast and how much the wind blows.

As a rule, wind speed increases with altitude and over open areas with no windbreaks. Good sites for wind plants are the tops of smooth, rounded hills, open plains or shorelines, and mountain gaps that produce wind funneling.

Wind speed varies throughout the country. It also varies from season to season. In Tehachapi, California, the wind blows more from April through October than it does in the winter. This is because of the extreme heating of the Mojave Desert during the summer months. The hot air over the desert rises, and the cooler, denser air above the Pacific Ocean rushes through the Tehachapi mountain pass to take its place. In a state like Montana, on the other hand, the wind blows more during the winter. Fortunately, these seasonal variations are a good match for the electricity demands of the regions. In California, people use more electricity during the summer for air conditioners. In Montana, people use more electricity during the winter months for heating.

WIND PRODUCTION

In 2006, wind machines in the United States generated a total of 26.6 billion kWh per year of electricity, enough to serve more than 2.4 million households. This is enough electricity to power a city larger than Los Angeles, but it is only a small fraction of the nation's total electricity production, about 0.4 percent. The amount of electricity generated from wind has been growing fast in recent years. In 2006, electricity generated from wind was 2 1/2 times more than wind generation in 2002.

New technologies have decreased the cost of producing electricity from wind, and growth in wind power has been encouraged by tax breaks for renewable energy and green pricing programs. Many utilities around the country offer green pricing options that allow customers the choice to pay more for electricity that comes from renewable sources.

Wind machines generate electricity in 28 different states in 2006. The states with the most wind production are Texas, California, Iowa, Minnesota, and Oklahoma.

Most of the wind power plants in the world are located in Europe and in the United States where government programs have helped support wind power development. The United States ranks second in the world in wind power capacity, behind Germany and ahead of Spain and India. Denmark ranks number six in the world in wind power capacity but generates 20 percent of its electricity from wind.

WIND AND THE ENVIRONMENT

In the 1970s, oil shortages pushed the development of alternative energy sources. In the 1990s, the push came from a renewed concern for the environment in response to scientific studies indicating potential changes to the global climate if the use of fossil fuels continues to increase. Wind energy is an economical power resource in many areas of the country. Wind is a clean fuel; wind farms produce no air or water pollution because no fuel is burned. Growing concern about emissions from fossil fuel generation, increased government support, and higher costs for fossil fuels (especially natural gas and coal) have helped wind power capacity in the United States grow substantially over the last 10 years.

The most serious environmental drawbacks to wind machines may be their negative effect on wild bird populations and the visual impact on the landscape. To some, the glistening blades of windmills on the horizon are an eyesore; to others, they’re a beautiful alternative to conventional power plants.

Computer-controlled LED lamp (bitrot)

2008-12-10T22:44:00.000-08:00

Wouldn't it be cool to have a desk lamp that could change color, for example flashing red when you receive a mail? Or that pulls weather reports from the Internet, and translates the forecast temperature to a color? It could add some white flashes if thunderstorms are forecast. Or when your phone rings, it could flash green if it's a friend or red if it's your boss, based on caller ID. The possibilities are endless.

This page shows you to build a lamp that can change color, and can be controlled by a computer. Simple Python and C programs for your PC or Mac are provided that let you program color patterns into the lamp. Implementing the weather forecast and other ideas are then up to you. Web scraping with wget is easy if you understand a scripting language. The whole project should cost under 100 euro, half of which is for the lamp (glass ball, LED module, microcontroller, and odds and ends), and the other half for the flash programmer if you don't have one.

There are enormously bright LEDs now, bright enough to be used as lamps. They also come with three emitters, red, green, and blue, on a single module, spaced closely enough that the colors mix. One such module is the Z-Power by Seoul Semiconductor. This page shows how to build a lamp using this module that can be programmed to show any color or cycle of colors, as instructed by a PC or Mac over a serial RS232 line. (Or USB, using a cheap USB-to-serial adapter - unfortunately USB cables cannot be longer than about two meters before they become either unreliable or very expensive.)

Building the lamp takes three steps:

Build the circuit. It's extremely simple. Install it into some suitable lamp with a diffusor; mine is a glass ball with a diameter of 20cm.
Program the microcontroller. This requires a programming device that works with Mac, Linux, or Windows computers. Cost is about 50 euro.
Connect the lamp to a computer, and run a program that controls the color of the lamp. Python and Linux C examples are included, but other platforms should be very easy to write.

The picture to the right shows the Z-Power LED assembly without heat sink. The mounting plate is about the size of a five-cent coin. I got mine at LEDs and more, but there are cheaper sources on the Internet. You should pay around 10 euro.

1. The hardware

The circuit consists of the Z-Power LED module, which must be mounted on a heat sink because it can run hot. Each LED is driven by a 9550 transistor connected to an Atmel ATMEGA 8-16PU microcontroller. A MAX-232 chip converts the serial signals of the microcontroller to RS-232 voltages. The circuit runs on 5V; I use a cheap power supply used for external USB hard disk enclosures that can be bought for a few euro. Only use the ground and 5V wires! The 12V wire can destroy the circuit. In the power supply I used, the cable wires did not follow the usual black/red/yellow color scheme for ground/5V/12V, so always check very carefully with a voltmeter!

Those Atmel microcontrollers are amazing. In one small 28-pin DIP package it contains an 8-bit microcontroller running at 1 MHz (up to 8 MHz with a an external crystal), 20 KB Flash memory, RAM, programmer ROM, parallel and serial ports, timers - it's a small computer on a chip that requires no external chips at all. Its parallel output pins can drive normal LEDs directly, but high-power LEDs require a driver transistor. This is a view of the breadboard under the lamp, and the LED assembly on its heat sink inside the lamp. Click here for a larger picture of the breadboard. Note the five-pin connector at the bottom with the rightmost pin marked black (GND); this is the programming interface that the AVR USB programmer plugs into. More on that below.

Here is the circuit diagram. I used a breadboard with small copper rings around the holes, and thin magnet wire (0.07mm) to wire up the pins. Magnet wire is normally used for winding electromagnets; I like it because it's insulated with a thin yellowish coating that burns off when soldered to a pin. For the connection to the LED assembly I used thicker wires with a conventional green plastic sheath.

You should be sufficiently familiar with soldering and TTL chips to attempt this. Chips in DIP packaging have an indentation at one end; pin 1 is to the left of that mark. Pin count then runs counter-clockwise. I recommend machined sockets, especially for the programmer connector. Sockets with metal tabs tend to become unreliable after a while. For Americans: the rectangular box side of the capacitor symbol is positive, like the curved side of the US symbol. Do not get the polarity wrong; and yes, the top left capacitor really does have its negative side connected to VCC. The MAX-232 chip uses DC-DC converters to generate +/-12V internally.

The speaker shown in the circuit diagram is not currently supported by the firmware. You should omit it. If you do add one, use a piezo-electric buzzer; a small plastic box that contains the piezo disc and a small buzzer chip. It will start beeping when DC power is applied. Do not use a normal speaker here.

2. The firmware

The microcontroller must be programmed with firmware that controls the LEDs and watches the serial interface. This is done in three steps:

Write the source code in C. (Or download it from the link below.)
Compile it to an executable program. I am using the AVR-GCC compiler, a cross-compilation C compiler suite available for Linux and other operating systems. It compiles the C code to a "hex" file. If you do not want to compile your own code, you'll find my hex file in the download package.
Download the hex file to the lamp microcontroller. You will need a programming device. I use the AVR programmer USB, all SMD, stk500 V2 compatible, sold for 50 euro by Tuxgraphics. It comes with sample code and USB drivers and programming tools for Linux, MacOS, and Windows. Make sure you get the "all SMD" version and not the big printed circuit board. The picture on the left shows the AVR programmer, it's really tiny. Tuxgraphics also sells the microcontroller cheaply; it should be between 3 and 4 euro.

The AVR programmer connects to the lamp microcontroller with a five-pin connector that is plugged into the lamp microcontroller board's programming connector. Make sure that you follow the pinout in the circuit diagram above: the AVR programmer's connector is color-coded so that gray = GND, brown = SCK, white = MISO, yellow = MOSI, and green = reset. Please check with the programmer's documentation in case they change the connector.

The AVR programmer can remain plugged in all the time during development. You can compile, download the hex file, and watch the firmware run on the lamp microcontroller without swapping cables. This makes for a fast development cycle. The download package contains a Makefile for Linux or the Mac (didn't try it on Windows) that will compile and download if you type make and make load.

The source code and control files are part of the download package at the end of this section. If you just want to take a look, here is the source code.

The code consists of several functions:

TIMER1_COMPA_vect is the interrupt handler. The Atmega's builtin timer calls it 6400 times per second. At a 1 MHz clock rate, it has only about 150 clock ticks to work with, so it must be very simple. It only picks up the current RGB color computed elsewhere, and flips the LED driver outputs accordingly. 64 calls of the interrupt routine take 10 ms. LED intensities are pulse-modulated in 64 levels: if n out of 64 consecutive calls turn an LED on and the others turn it off, then that LED has a brightness of n/64. Effectively, the lamp can show 64³ or 262144 colors; fewer colors cause perceptible stepping when smoothly cycling through color ranges. The 10ms (100Hz) repeat rate of a 64-call run also cannot be slowed much without causing flickering. This means that the microcontroller is operating close to its computational capacity.
recalculate computes the current LED color that is converted to LED pulses by the interrupt handler. It loops over up to sixteen actions and composites them like layers of paint. Each action consists of
- foreground color: the color shown when the current pattern bit is 1.
- background color: the color shown when the current pattern bit is 0.
- pattern: a 16-bit bitmap that controls whether the action shows the background color (0) or foreground color (1). Bit 0 of the bitmask comes first and bit 15 comes last.
- speed: the duration of each bit of the pattern in 20ms units. A value of 50 makes each pattern bit last a second. A value of 0 disables this action.
- length: the length of the pattern. If this is greater than 16, the pattern bitmap is padded with zero bits.
- override: the length of the pattern during which the action is not composited with lower-numbered actions, but wipes the slate and starts with black again.
- repeat: number of repetitions of the pattern. If set to 1, this is a one-shot action. 0 means forever.
- soft: if false, the bitmap bits switch between both colors. If true, the colors are smoothly faded.
- blend: if false, the foreground color overwrites lower action colors; if true it is added like a watercolor. The background color is always blended.
See below for some examples to use these to achieve effects. The whole notion of actions is based on the idea that once programmed by the PC or Mac, the lamp can be left to itself to execute complex color patterns without continuous intervention by the PC. A PC could not possibly keep up with the timing demands.
main first initializes the microcontroller, starting the timer interrupts and clears the actions to a default rainbow cycling pattern, and then listens for incoming bytes on the serial interface. When a command comes in, it is buffered and passed to parser_serial, which modifies an action.
It also periodically calls the recalculate function when the interrupt handler reports a 64-interrupt cycle has completed and new colors are needed; this happens every 10ms.

You can download the firmware here, in gzipped tar format (can be unpacked with tar xzvf ledlamp-firmware.tgz on Linux and MacOS, or most unzippers on Windows with CR/LF expansion disabled):

http://www.bitrot.de/ledlamp-firmware.tgz

The tar file includes the C source code, Makefile, and a hex file that can be directly downloaded to the lamp microcontroller. With the hex file, you only need the Tuxgraphics AVR programmer, but you don't need an ACR C compiler - provided you do not plan to modify the firmware. If you do, use make to recompile the source code, and make load to download the modified firmware into the lamp.

3. Desktop computer control

After turning on the lamp, it slowly cycles through six colors. But you can control it with your PC or Mac by connecting the serial interface to your PC or Mac. You need to connect the lamp's RxD input to an RS-232 sub-D connector: of the nine pins, you only need to connect pin 2 to the lamp's RxD, and pin 7 to the lamp's GND. You can also connect pin 3 to the lamp's TxD, but the back channel currently just echoes back what the lamp has received on RxD. This is useful for debugging; if you get an echo the lamp firmware is working. This 9-pin connector then goes into your PC's serial connector, or if it doesn't have one (like Macs), into a USB/serial adapter available for some 10 euro.

You can then connect to the lamp with a terminal program such as minicom. Set it to 9600 baud, one stop bit, no parity, no software flow control, no hardware flow control (CTS/DTS). On Linux, the first serial port has the name /dev/ttyS0; if you are using the USB/serial adapter it's /dev/ttyUSB0. Depending on your motherboard wiring, it might be /dev/ttyS1 instead of S0. The Windows names are COM0 or COM1. I don't know under what names the USB/serial adapters show up but I believe it's a COMn for some n in the range between 0 and 15. (Do not change the Atmega firmware to more than 9600 baud, that is not reliable.)

You can now send commands to the lamp. If you have connected the lamp's TxD line, the characters will be echoed to you; it you didn't, you may be typing blindly with no characters appearing on the screen. All commands are lines of text ending in a newline (CR, LF, or both). Blanks and tabs are ignored. All numbers must have an exact length (one, two, four, or six digits); all numbers are hexadecimal. In the descriptions below, the digit 0 is shown in places where a number (0..f) is expected.

Each command begins with the following characters:

+0: enable an action. The 16 available actions are numbered 0..f.
-0: disable an action.
=0: reprogram an action.

No characters may follow the + and - commands. The = command must be followed by zero or more of the following subcontrols that closely follow the action fields described above:

f000000: the foreground color as an RRGGBB value. For each of R, G, and B, 00 means off and 40 means 100% on.
b000000: the background color as an RRGGBB value.
p0000: the 16-bit bitmap that controls whether the action shows the background color (0) or foreground color (1). Pattern bit 0 is shown first, then 1, and so on.
s0000: the duration of each bit of the pattern in 20ms units. A speed of zero disables the action.
l00 (lowercase L): the length of the pattern. If this is greater than decimal 16 (hex 10), the pattern bitmap is padded with zero bits.
o00: override; the length of the pattern during which the action is not composited with lower-numbered actions.
r00: number of repetitions of the pattern. 0 means forever.
S: soft blend: foreground and background colors are smoothly faded. Opposite of H.
H: hard: foreground and background colors are switched. Opposite of S.
C: clear action; set all fields to zero. Typically used at the beginning of a command to reprogram an action.
A: activate the action, as if a + command had followed the reprogramming command. Typically used at the end of the command.

These following table shows the default actions created when the lamp boots, and that cause it to begin cycling through the rainbow. Note how the patterns are staggered: the first uses bits 0 and 1, the next uses bits 2 and 3, and so on. They are all started at the same time with the same speeds, so they stay synchronized. Each action shows its foreground color for two ticks (two consecutive pattern bits are on), so the soft blending to the next tick will show the foreground color for a full tick, and not just reach it very briefly and immediately begin to fade to the next.

action	command	comment
0	`=0` `f400000` `b000000` `p0003` `l0a` `r00` `s32` `S` `A`	program action 0 foreground color is full red background color is black bit pattern is --------** (red for first two ticks) length of bit pattern is decimal 10 repeat forever speed is decimal 50 * 20ms units, one pattern bit lasts one second blend softly between foreground and background color activate action now
1	`=1` `f004000` `b000000` `p000c` `l0a` `r00` `s32` `S` `A`	program action 1 foreground color is full green see above bit pattern is ------**-- (green for next two ticks) see above see above see above see above see above
2	`=2` `f400030` `b000000` `p0030` `l0a` `r00` `s32` `S` `A`	program action 2 foreground color is magenta see above bit pattern is ----**---- (magenta for next two ticks) see above see above see above see above see above
3	`=3` `f401400` `b000000` `p00c0` `l0a` `r00` `s32` `S` `A`	program action 3 foreground color is yellow see above bit pattern is --**------ (yellow for next two ticks) see above see above see above see above see above
4	`=4` `f000040` `b000000` `p0300` `l0a` `r00` `s32` `S` `A`	program action 4 foreground color is full blue see above bit pattern is **-------- (blue for last two ticks) see above see above see above see above see above

The commands are shown on multiple lines for clarity; if sent over the serial interface they must be all on one line, and they must be terminated with a newline. Here are some additional preprogrammed actions that are not enabled after booting (the final A is missing):

action	command	comment
5	`=5` `f404040` `b000500` `p02aa` `l0b` `o0b` `r01` `s02` `H`	program action 5: five fast white flashes foreground color is full white background color is dark green bit pattern is ----- (alternate between white and dark green) length of bit pattern is decimal 11 override lower actions during entire white/dark green flashing run pattern only once speed is 2 20ms units, the entire action lasts 11220 = 440ms hard switching between white and dark green, no blending
6	`=6` `f400000` `b000000` `p002a` `l20` `o07` `r2e` `s0a` `H`	program action 6: red triple pulses for five minutes foreground color is full red background color is black bit pattern is ------------- (three red pulses, otherwise black) length of bit pattern is decimal 32 (pattern controls only first 16) override lower actions during the red pulses only run pattern decimal 46 times speed is 10 20ms units, the entire action lasts 463210*20ms = 5 minutes hard switching between red and black, no blending
7	`=7` `f000040` `b400000` `p5555` `l10` `o10` `r00` `s04` `H`	program action 7: pulse red/blue forever foreground color is full blue background color is full red bit pattern is -------- (alternate red and blue) length of bit pattern is decimal 16 override lower actions permanently run pattern indefinitely speed is 4 * 20ms units, 1000/(2420) = 6.25 pulses per second soft blending between red and blue
8	`=8` `f000000` `b000040` `p0055` `l08` `o02` `rb9` `s02` `H`	program action 8: blue flashing for one minute foreground color is black background color is full blue bit pattern is ---- (alternate black and blue) length of bit pattern is 8 override lower actions for the first of every four flashes run pattern decimal 185 times speed is 2 * 20ms units, action runs for 18582*20ms = 1 minute hard switching between blue and black, no blending
9	`=9` `f000000` `b400000` `p0055` `l08` `o08` `rb9` `s02` `H`	program action 9: red flashing for one minute foreground color is black background color is full red bit pattern is ---- (alternate black and red) length of bit pattern is 8 override lower actions for the entire duration run pattern decimal 185 times speed is 2 * 20ms units, action runs for 18582*20ms = 1 minute hard switching between red and black, no blending

To activate one of the actions 5 through 9, send a command such as +5 followed by a newline. Similarly, to stop a running action, send a command such as -5. The actions a through f are not preprogrammed but can be programmed with a command beginning with =a or similar. All actions can be reprogrammed at any time.

Here is a simple Python script that starts action 5. It assumes that your lamp is attached to an USB port using an USB/serial adapter, and that the script runs on Linux. If this is not the case, please replace /dev/ttyUSB0 with the appropriate device name on your computer. Make sure that you have read and write permissions for the device node; you may have to chmod 666 it as root.

  import termios

 lamp = open("/dev/ttyUSB0", "w")
 [iflag, oflag, cflag, lflag, ispeed, ospeed, cc] = termios.tcgetattr(lamp)
 termios.tcsetattr(lamp, termios.TCSANOW,
  [iflag, oflag, cflag, lflag, termios.B9600, termios.B9600, cc])

 def tell_lamp(command):
     lamp.write(command + "\n")
     lamp.flush()

 tell_lamp("+5")

Here is a program written in C that allows sending commands to the lamp from the command line, one command per argument word. Again, replace the device name with one that is appropriate for your system.

  #include 
 #include 
 #include 
 #include 

 int fd;

 void init()
 {
     fd = open("/dev/ttyUSB0", O_RDWR);
     if (fd < 0) {
         perror("/dev/ttyUSB0");
         fprintf(stderr, "cannot connect to LED lamp\n");
         return;
     }
     struct termios tc;                  // 9600 baud, 8n1, no flow control
     tcgetattr(fd, &tc);
     tc.c_iflag = IGNPAR;
     tc.c_oflag = 0;
     tc.c_cflag = CS8 | CREAD | CLOCAL;
     tc.c_lflag = 0;
     cfsetispeed(&tc, B9600);
     cfsetospeed(&tc, B9600);
     tcsetattr(fd, TCSANOW, &tc);
 }

 void send(
     const char *command)                // send this command
 {
     write(fd, command, strlen(command));
     write(fd, "\n", 1);
 }

 void main(
     int        argc,                    // number of command-line options
     const char **argv)                  // each argument word is one command
 {
     init();
     for (int i=1; i < argc; i++)
         send(argv[i]);
 }

Enjoy! And please tell me about your experiences and modifications.

Michael McTernan has also built a similar lamp, and he has added an Ethernet interface too. Tuxgraphics now offers the necessary components for under 10 Euro

Seven Component Regulated LED Lamp (solorb)

2008-12-10T22:41:00.000-08:00

Circuit board installed in an automotive lamp holder, attached to a fluorescent lamp base

Seven Component Regulated LED Lamp

Updated March, 2003

Introduction

This is a minimal parts lamp made with four white LEDs. It features regulated light output from 10V to around 20V and works well as a flashlight.

Specifications

Nominal Operating Voltage: 12V DC
Operating Current: 40ma

Theory

The LM317L and resistor act as a current regulator set to 40ma. Current flows from the battery through one pair of LEDs, through the regulator, through the other pair of LEDs, and back to the battery. The capacitor filters out noise on the power supply lines. The LED pairs must be matched so that the current through them is roughly equivalent. Small resistors could be placed in series with each of the four LEDs to improve the balance, but the parts count would go way up.

Construction

There is one trick with this circuit, matched pairs of LEDs must be used. Normally, a batch of LEDs from the same manufacturer will be matched close enough for this application. If unmatched LEDs are used, one LED per pair will be bright and the other one will be dim. It is best to first build the circuit on a plug-in proto board to verify that the LEDs light evenly.

A small circuit board was made using press-n-peel blue film, the board was cut into a circular shape using a nibbling tool. The parts were soldered in, and the board was mounted inside of the bottle cap. The bottle cap protects the LEDs and prevents bright light from coming out of the side of the assembly. The cap came from a 1 Liter "Aqua Fina" brand water bottle. The single screw can be used to mount the assembly to an external bracket.

The completed circuit board and cap assembly was mounted in an old automobile turn signal. The lamp head was mounted onto the end of an old fluorescent lamp base with a goose neck adjustable arm. The resulting lamp is quite effective for night reading, and it's not too ugly.

Alignment

If you have a variable power supply, it is best to bring the voltage up slowly the first time power is applied to the circuit. If any of the LEDs don't light, turn off the power and fix the problem. If all of the LEDs light up evenly, the circuit should work (for many years) on 12V.

Use

Connect this circuit to a 12V battery or power supply, be sure to observe the correct polarity. The LEDs should put out a bright white light. You can read by this light, and it is useful for emergency illumination. The low current draw allows it to run for many hours on a battery.

Parts

4x white LEDs (matched), T1-3/4 size
1x 30 ohm 1/4 W resistor
1x 0.1uF capacitor
1x LM317L adjustable voltage regulator
1x plastic bottle top from a water bottle (1 liter Aqua Fina brand)
1x 4-40 3/8" screw
2x 4-40 nuts

Parts Sources

Jameco 1-800-831-4242 http://www.jameco.com/
Digi-Key 1-800-DIGIKEY http://www.digikey.com/

How 9W LED Bulb Beat 70W Incandescent (treehugger)

2008-12-10T22:38:00.000-08:00

I've seen my fair share of LED bulbs, but usually the lumens they output are fairly modest. This bulb, however, outputs 308 lumens using 150 warm white LEDs, and is rated at 9 Watts. It is said to be a replacement for a regular 70 Watt incandescent bulb. There's also a frosted version available that outputs about 594 lumens.

Differences in light quality from LED bulbs
One thing to note is that the light from these bulbs is probably a bit different in character from incandescents. LED light tends to be sharper and more direct (perhaps the frosted bulb overcomes this problem). The bulbs cost between $60-$70 each, and you can find them at X-Treme Geek and Cyberguys. Why would you pay this much for a bulb? Perhaps if you are off-grid or interested in long-term savings.

LED Vs Traditional Flashlights(ezinearticles)

2008-12-10T22:35:00.000-08:00

A flashlight is essential for every homeowner, vehicle owner and tenant to be prepared in case of an emergency. How do we know what to look for when buying a flashlight? Which features are important? How do we shop for a flashlight that will withstand use, and be ready in case an emergency does occur? Using a LED light can yield results crisper than traditional flashlights -which are beneficial to the user as they can provide a brighter colored light

What type of power are you seeking for the flashlight? Many owners prefer battery power, compared to wind-up, or chargeable flashlights. Purchasing a flashlight that uses batteries as its main source of power means that extra batteries can be stored, and used within extended blackout periods, or longer emergencies. Battery powered flashlights allow the owner to feel more secure in their home, or vehicle - as extra batteries should always be on hand (just in case of an emergency).

LED Flashlights vs. traditional Flashlights offer beneficial features which are causing customers to make the transition between the traditional bulbs and the updated LED versions. These features outlined below are the reasons that LED lights are becoming popular not only in flashlights but other lights like Christmas lights and the lights used in vehicles. Advances in LED technology have created lights that have risen to the top of the market.

LED lights, although a relatively new development have been growing in popularity. What are the benefits of LED flashlights compared to traditional flashlights? LED flashlights are of the latest technology and provide a clear and concise beam of light, making the light more effective.

LED stands for light emitting diode - LED lights provide more powerful lights and have the ability to last ten times longer than traditional flashlight bulbs. Did you know that most models of powerful LED lights have the capability provide over one-hundred hours of light before the battery needs to changed or replaced? Unlike traditional flashlights, LED lights also have the capability to remain cool to the touch, not emitting heat after being on for an extended period of time, like normal lights. This new technology has proven itself from within the household, to the fire and police department to companies providing roadside assistance.

LED flashlights often come equipped with advanced features, such as: strobe light functions which can be useful when trying to gain attention from passersby if requiring attention while in a vehicle, or dealing with an emergency situation. LED stroke light functions are available in most LED flashlights meant to be used for a variety of purposes.

When buying a flashlight, it is important that the light be able to withstand dropping, be water resistant and is able to maintain the light through a variety of situations. LED lights have been proven stronger than traditional flashlights, and are used within a variety of industries. From the fire fighting teams, police officers and other emergency services, LED lights are the choice of each of these professions!

Rob Rich is the president and CEO of MEI Research, a Temecula, California- based company with many lighting/equipment manufacturing property supply for consumers, businesses, and the military. For more information on LED flashlights, check out http://www.action-lights.com

Article Source: http://EzineArticles.com/?expert=Rob_Rich

The Benefits of LEDs (powerlineleds)

2008-12-10T22:30:00.000-08:00

Designed as drop-in replacements, DDP® LED lamps offer several advantages compared to incandescent bulbs:

	DDP® LED Lamp	Incandescent Bulb
Average Life	100,000 hours	2,000 hours
Failure Mode	Predictable	Unpredictable
Lifetime affected by on/off operation	No	Yes
Resistant to shock and vibration	Yes	No
Operating temperature	Low	High
Power consumption	Low	High
Susceptible to cold filament inrush current	No	Yes

The primary benefit of DDP® LED technology is the tremendous cost savings for the user as a result of eliminating replacement cost, lowering power consumption, and reducing operating temperatures. Moreover, DDP® LED lamps improve efficiency by providing reliable status indication.

Cost Savings
Based on an average incandescent bulb life of three months, converting to DDP® LEDs will pay for itself in material costs alone within the first year. This payback period is only considering the cost of the incandescent bulb. It does not take into account the labor cost associated with changing bulbs, power savings, operating downtime, incandescent bulb inventory and ordering costs, and other significant factors. The following graph depicts the average cost of replacing a $2.00 24X incandescent bulb in one socket four times a year. The cost of the bi-polar 24L4-R1 is fixed at $5.00 for ten years.

For a facility with only 1,000 lamps, the material savings alone would be approximately $3,000 after the first year!

Long Life
The most compelling advantage of using DDP® LED lamps is a predictable life. LEDs are solid-state devices and, by definition, control current without heated filaments. When used within its design parameters, a DDP® LED lamp will operate up to 100,000 hours (or 10 years). Furthermore, LED lifetime is not shortened by turning the lamp on and off.

* The life of an incandescent bulb is unpredictable - subject to catastrophic failure due to shock, vibration, or cold filament inrush current. Initial powering of a control panel with numerous incandescent bulbs will generally result in several failures.

Cooler Operations
Since incandescent bulbs generate light by heating a filament, they also heat the lenses they illuminate. This causes discoloration and eventual melting of the control panel lenses. DDP® LED lamps generate much less heat than the incandescent bulbs they replace. Furthermore, heat is dissipated through the base of the LED lamp, keeping the lens cooler.

Lens melting and discoloration is so common with extended use of incandescent bulbs, DDP offers replacement lenses for several industry-standard sockets.

Power Consumptions
LEDs generally draw much lower current than incandescent bulbs.

DDP® LED Lamp		Incandescent Bulb
6S6L120-CWX	11mA	6S6/120V	50mA
120PSBL-NWX	5.8mA	120PSB	25mA
387L-X1	16mA	387	40mA
1819L-X-CX	17mA	1819	40mA

While lower power consumption reduces operating costs, it also reduces wear on other components in the application such as transformers, batteries and power converters.

Cold Filament Inrush
When cold, and incandescent filament draws ten times as much current as it does during normal operation. The initial powering of hundreds of incandescent bulbs simultaneously causes significant voltage surges that lead to lamp failures.

DDP LED lamps are designed with series resistors to limit the operating current, resulting in no cold filament current variation.

Shunt Resistor
Because noise current as low as .25mA may cause the LED to illuminate dimly in the off state, DDP® LEDs are available with an optional built-in shunt resistor to bleed-off residual current. There are several sources of leakage current in a circuit. Transient voltage from a relay or discharge from a capacitor creates circuit noise. Also, inherent in the design of some programmable logic controllers (PLCs), is a triac protective circuit that may supply up to 5mA of leakage current in the off state.

LED Technology (Wiki)

2008-12-10T22:26:00.000-08:00

An LED lamp is a type of solid state lighting (SSL) that uses light-emitting diodes (LEDs) as the source of light, rather than electrical filaments plasma (used in arc lamps such as fluorescent lamps), or gas.

LED lamps (also called LED bars or Illuminators) are usually clusters of LEDs in a suitable housing. They come in different shapes, including the standard light bulb shape with a large E27 Edison screw and MR16 shape with a bi-pin base. Other models might have a small Edison E14 fitting, GU5.3 (Bipin cap) or GU10 (bayonet socket). This includes low voltage (typically 12 V halogen-like) varieties and replacements for regular AC mains (120-240 V AC) lighting. Currently the latter are less widely available but this is changing rapidly.

History

The phenomenon of solid state junctions producing light was discovered in the crystal detector era. In the 1960s commercial red LED's became available, and by the 1970s these were in widespread use as indicators in a very wide range of equipment. These early LED's had much too small an output to be useful as lighting. They replaced the previously widely used indicator types of filament lamps and neon. Compared to neon, indicator LED's have longer lifetimes and run on lower voltage; compared to miniature filament lamps, indicator LED's have much longer lifetimes, such that they do not require replacement, and consume less power. The lack of need for replacement also eliminates the need for bulb sockets and a user access port.

Commercial amber (yellow) and orange LED's followed, and were used where differentiation of multiple LEDs was required. For many years LED's came in infra-red, red, orange, yellow, and green. Blue, cyan, and violet LEDs finally appeared in the 1990s.

To produce a white SSL device, a blue LED was needed. In 1993, Shuji Nakamura of Nichia Corporation came up with a blue LED using gallium nitride (GaN). With this invention, it was now possible to create white light by combining the light of separate LED's (red, green, and blue), or by placing a blue LED in a package with an internal light converting phosphor. With the phosphor type, some of the blue output becomes either yellow or red and green with the result that the LED light emission appears white to the human eye.

In 2008, SSL technology advanced to the point that Sentry Equipment Corporation in Oconomowoc, Wis. was able to light its new factory almost entirely with LEDs, both interior and exterior. Although the initial cost was three times more than a traditional mixture of incandescent and fluorescent bulbs, the extra cost will be repaid within two years from electricity savings, and the bulbs should not need replacement for 20 years.[3]

Technology overview

A single LED can produce only a limited amount of light, and only a single color at a time. To produce the white light necessary for SSL, light spanning the visible spectrum (red, green, and blue) must be generated in approximately correct proportions. To achieve this, three approaches are used for generating white light with LEDs: wavelength conversion, color mixing, and most recently Homoepitaxial ZnSe.

Wavelength conversion involves converting some or all of the LED’s output into visible wavelengths. Methods used to accomplish this feat include:

Blue LED & yellow phosphor – Considered the least expensive method for producing white light. Blue light from an LED is used to excite a phosphor which then re-emits yellow light. This balanced mixing of yellow and blue lights results in the appearance of white light, but produces poor color rendition (i.e., has low CRI).
Blue LED & several phosphors – Similar to the process involved with yellow phosphors, except that each excited phosphor re-emits a different color. Similarly, the resulting light is combined with the originating blue light to create white light. The resulting light, however, has a richer and broader wavelength spectrum and produces a higher color-quality light, albeit at an increased cost.
Ultraviolet (UV) LED & red, green, & blue phosphors – The UV light is used to excite the different phosphors, which are doped at measured amounts. The colors are mixed resulting in a white light with the richest and broadest wavelength spectrum.
Blue LED & quantum dots – A process by which a thin layer of nanocrystal particles containing 33 or 34 pairs of atoms, primarily cadmium and selenium, are coated on top of the LED. The blue light excites the quantum dots, resulting in a white light with a wavelength spectrum similar to UV LEDs.

Color mixing involves using multiple colors of LEDs in a lamp to produce white light. Such lamps contain a minimum of two LEDs (blue and yellow), but can also have three (red, blue, and green) or four (red, blue, green, and yellow). As no phosphors are used, there is no energy lost in the conversion process, thereby exhibiting the potential for higher efficiency.

Homoepitaxial ZnSe is a technology developed by Sumomito Electric where a LED is grown on a ZnSe substrate, which simultaneously produces blue light from the active region and yellow emission from the substrate. The resulting white light has a wavelength spectrum on par with UV LEDs. No phosphors are used, resulting in a higher efficiency white LED.

To be considered SSL, however, a multitude of LEDs must be placed close together in a lamp to add their illuminating effects. This is because an individual LED produces only a small amount of light, thereby limiting its effectiveness as a replacement light source. In the case where white LEDs are utilized in SSL, this is a relatively simple task, as all LEDs are of the same color and can be arranged in any fashion. When using the color-mixing method, however, it is more difficult to generate equivalent brightness when compared to using white LEDs in a similar lamp size. Furthermore, degradation of different LEDs at various times in a color-mixed lamp can lead to an uneven color output. Because of the inherent benefits and greater number of applications for white LED based SSL, most designs focus on utilizing them exclusively.

Driving LEDs

LEDs have very low dynamic resistance, with the same voltage drop for widely varying currents. Consequently they can not connect direct to most power sources without causing self destruction. A current control ballast is normally used, which is sometimes constant current.

Indicator LEDs

Miniature indicator LEDs are normally driven from low voltage DC via a current limiting resistor. Currents of 2mA, 10mA and 20mA are common. Some low current indicators are only rated to 2mA, and should not be driven at higher current.

Sub-mA indicators may be made by driving ultrabright LEDs at very low current. Efficacy tends to reduce at low currents, but indicators running on 100uA are still practical. The cost of ultrabrights is higher than 2mA indicator LEDs.

LEDs have a low max repeat reverse voltage rating, ranging from apx 2v to 5v, and this can be a problem in some applications. Back to back LEDs are immune to this problem. These are available in single color as well as bicolor types. There are various strategies for reverse voltage handling.

In niche applications such as IR therapy, LEDs are often driven at far above rated current. This causes high failure rate and occasional LED explosions. Thus many parallel strings are used, and a safety screen and ongoing maintenance are required.

Alphanumeric LEDs

These use the same drive strategy as indicator LEDs, the only difference being the larger number of channels, each with its own resistor. 7 segment and starburst LED arrays are available in both common anode or common cathode forms.

Lighting LEDs on mains

A CR dropper (capacitor & resistor) followed by full wave rectification is the usual ballast with mains driven series-parallel LED clusters.

A single series string would minimise dropper losses, but one LED failure would extinguish the whole string. Parallelled strings increase reliability. In practice usually 3 strings or more are used.

Operation on square wave and modified sine wave (MSW) sources, such as many inverter, causes heavily increased resistor dissipation in CR droppers, and LED ballasts designed for sine wave use tend to burn on non-sine waveforms. The non-sine waveform also causes high peak LED currents, heavily shortening LED life. An inductor & rectifier makes a more suitable ballast for such use, and other options are also possible.

Lighting LEDs on low voltage

LEDs are normally operated in parallel strings of series LEDs, with the total LED voltage typically adding up to around 2/3 of the supply voltage, and resistor current control for each string.

In resistor-drive devices, LED current is then proportional to power supply (PSU) voltage minus total LED string voltage. Where battery sources are used, the PSU voltage can vary widely, causing large changes in LED current and therefore color and light output. For such applications, a constant current regulator is preferred to resistor control. Low drop-out (LDO) constant current regs also allow the total LED string voltage to be a higher percentage of PSU voltage, resulting in improved efficiency and reduced power use.

Torches run one or more lighting LEDs on a low voltage battery. These usually use a resistor ballast.

In disposable coin cell powered keyring type LED lights, the resistance of the cell itself is usually the only current limiting device. The cell should not therefore be replaced with a lower resistance type, such as one using a different battery chemistry.

Finally, an LED can be run from a single cell by use of a constant current switched mode inverter. While adding additional expense, this method provides a high level of color and brightness control, and ensures longer LED lifetime.

Comparison to other lighting technologies

Incandescent lamps (light bulbs) create light by running electricity through a thin filament, thereby heating the filament to a very high temperature so that it glows and produces visible light. A broad range of visible frequencies are naturally produced, yielding a pleasing warm yellow or white color quality. The incandescing process, however, is highly inefficient, as over 98% of its energy input is emitted as heat.^{[citation needed]} A standard 100 watt 120 VAC light bulb produces about 1700 lumens, about 17 lumens per watt. Incandescent lamps are relatively inexpensive to produce. The typical lifespan of a mains incandescent lamp is around 1,000 hours.^{[citation needed]} They work well with dimmers. Most existing light fixtures are designed for the size and shape of these traditional bulbs.

Fluorescent lamps (light bulbs) work by passing electricity through mercury vapor, which in turn produces ultraviolet light. The ultraviolet light is then absorbed by a phosphor coating inside the lamp, causing it to glow, or fluoresce. While the heat generated by fluorescent lamps is much less than its incandescent counterpart, energy is still lost in generating the ultraviolet light and converting this light into visible light. If the lamp breaks exposure to mercury can occur. Linear fluorescent lamps are typically five to six times the cost of incandescent lamps^{[citation needed]}, but have life spans around 10,000 and 20,000 hours. Lifetime varies from 1,200 hours to 20,000 hours for compact fluorescent lamps.

The efficacy of fluorescent tubes with modern electronic ballast commonly averages 50 to 67 lm/W overall. Most compact fluorescents rated at 13 watts or more with integral electronic ballasts achieve about 60 lumens/watt. Those with "iron" ballasts flicker at 100 or 120 Hz, and are less efficient. Most fluorescent luminaires are not compatible with dimmers. The quality of the light tends to be a harsh white because of the lack of a broad band of frequencies. To prevent mercury release, fluorescent tubes should be recycled by specialist routes rather than included in general refuse.

Neon lamp (light bulbs) used like night-lamp in children's room. Typically a 230 V (in Europe) is rated 0.5 W of power.

SSL/LEDs LEDs come in multiple colors, which are produced without the need for filters. A white SSL can be comprised of a single high-power LED, multiple white LEDs, or from LEDs of different colors mixed to produce white light. Advantages include:
- High efficiency - LEDs are now available that reliably offer over 100 lumens from a one-watt device, or much higher outputs at higher drive currents
- Small size - provides design flexibility, arranged in rows, rings, clusters, or individual points
- High durability - no filament or tube to break
- Life span - in properly engineered lamps, LEDs can last 50,000 - 60,000 hours
- Full dimmability – unlike fluorescent lamps, LEDs can be dimmed using pulse-width modulation (PWM - turning the light on and off very quickly at varying intervals). This also allows full color mixing in lamps with LEDs of different colors.^[1]
- Mercury-free - unlike fluorescent and most HID technologies, LEDs contain no hazardous mercury or halogen gases

However, some current models are not compatible with standard dimmers. It is not currently practical to produce high levels of room lighting. As a result, current LED screw-in light bulbs offer either low levels of light at a moderate cost, or moderate levels of light at a high cost. In contrast to other lighting technologies, LED light tends to be directional. This is a disadvantage for most general lighting applications, but can be an advantage for spot or flood lighting.

Because individual LEDs are low-voltage DC devices, implementing SSL to operate from mains AC requires well designed circuitry and a thermal case to dissipate the heat.

Applications

This garden light can use stored solar energy because of the low power consumption of its LED

Traffic lights
Automotive lighting
Stage lighting
Bicycle lighting
Flashlight (Electric torches)
Domestic lighting
Public Transit Vehicle Destination signs
Billboard displays
Floodlighting of buildings
Display lighting in art galleries to achieve a low heating effect on pictures etc.
Train lights and Train Signals (Now common on nearly all modern and most older MU's and Loco's in the UK)

Challenges

The current manufacturing process of white LEDs has not matured enough for them to be produced at low enough cost for widespread use. There are multiple manufacturing hurdles that must be overcome. The process used to deposit the active semiconductor layers of the LED must be improved to increase yields and manufacturing throughput. Problems with phosphors, which are needed for their ability to emit a broader wavelength spectrum of light, have also been an issue. In particular, the inability to tune the absorption and emission, and inflexibility of form have been issues in taking advantage of the phosphors spectral capabilities.

More apparent to the end user, however, is the low Color Rendering Index (CRI) of current LEDs. The current generation of LEDs, which employs mostly blue LED chip + yellow phosphor, has a CRI around 70, which is much too low for widespread use in indoor lighting. (CRI is used to measure how accurately a lighting source renders the color of objects. Sunlight and some incandescent lamps have a perfect CRI of 100, while white fluorescent lamps have CRI varying from the 50s to 98.) Better CRI LEDs are more expensive, and more research & development is needed to reduce costs. End user costs are still too high to make it a viable option, for instance, Maplin's website quotes comparable LED spots at £9.99 GBP[4] against the standard Halogen lamp twin pack which comes in at £6.49 GBP[5] (or roughly £3.25 GBP each).

Variations of CCT (color correlated temperature) at different viewing angles present another obstacle against widespread use of white LED. It has been shown, that CCT variations can exceed 500 K, which is clearly noticeable by human observer, who is normally capable of distinguishing CCT differences of 50 to 100 K in range from 2000 K to 6000 K, which is the range of CCT variations of daylight.

LEDs also have limited temperature tolerance and falling efficiency as temperature rises. This limits the total LED power that can practically be fitted into lamps that physically replace existing filament & compact fluorescent types. R&D is needed to improve thermal characteristics.

The long life of SSL products, expected to be about 50 times the most common incandescent bulbs, poses a problem for bulb makers, whose current customers buy frequent replacements.[6]

Research and development

Feb 2008 - Bilkent university - Turkey reports 300 lumens of visible light per watt luminous efficacy (not per electrical watt) and warm light by using nanocrystals ^[2].

Philips Lighting has ceased research on compact fluorescents, and is devoting the bulk of its R.& D. budget, 5 percent of the company’s global lighting revenue, to SSL. [7]

US

Department of Energy

In May 2008 the U.S. Department of Energy (DOE) announced details of the Bright Tomorrow Lighting Prize competition. The L Prize™ is the first government-sponsored technology competition designed to spur lighting manufacturers to develop high quality, high efficiency solid-state lighting products to replace the common light bulb. The competition will award cash prizes, and may also lead to opportunities for federal purchasing agreements, utility programs, and other incentives for winning products.

The Energy Independence and Security Act (EISA) of 2007 authorizes DOE to establish the Bright Tomorrow Lighting Prize competition. The legislation challenges industry to develop replacement technologies for the most commonly used and inefficient products, 60W incandescent lamps and PAR 38 halogen lamps. The L Prize specifies technical requirements for these two competition categories. Lighting products meeting the competition requirements would consume just 17% of the energy used by most incandescent lamps in use today. A future L Prize program announcement will call for development of a new “21st Century Lamp,” as authorized in the legislation.

The EISA legislation establishes basic requirements and prize amounts for each category. The legislation authorizes up to $20 million in cash prizes. [8] [9]

National Institute of Standards and Technology

In June 2008 scientists at the National Institute of Standards and Technology (NIST) announced the first two standards for solid-state lighting in the United States. These standards detail the color specifications of LED lamps and LED light fixtures, and the test methods that manufacturers should use when testing these solid-state lighting products for total light output, energy consumption and chromaticity, or color quality.

The Illuminating Engineering Society of North America (IESNA) published a documentary standard LM-79, which describes the methods for testing solid-state lighting products for their light output (lumens), energy efficiency (lumens per watt) and chromaticity.

The solid-state lights being studied are intended for general illumination, but white lights used today vary greatly in chromaticity, or specific shade of white. The American National Standards Institute (ANSI) published the standard C78.377-2008, which specifies the recommended color ranges for solid-state lighting products using cool to warm white LEDs with various correlated color temperatures. The standard may be downloaded from ANSI’s Web site. [10]

DOE is launching the Energy Star program for solid-state lighting products later in 2008. NIST scientists assisted DOE by providing research, technical details and comments for the Energy Star specifications. The Energy Star certification assures consumers that products save energy and are high quality and also serves as an incentive for manufacturers to provide energy-saving products for consumers.

The solid-state lighting community is continuing to develop LED lighting standards for rating LED lamp lifetime and for measuring the performance of the individual high-power LED chips and arrays. NIST scientists are taking active roles in these continuing efforts.

NIST is working with the U.S. Department of Energy (DOE) to support its goal of developing and introducing solid-state lighting to reduce energy consumption for lighting by 50 percent by the year 2025. The department predicts that phasing in solid-state lighting over the next 20 years could save more than $280 billion in 2007 dollars. [11]

Photovoltaic vs Wind Turbine for Home

2008-12-09T03:37:00.000-08:00

First reference can be download at :
http://www.detronics.net/wind_solar.pdf

It may seem that environmentalist make solar power and other alternatives over exaggerate, they are actually very good forms of energy production that many people can make use of. Although it obviously uses up energy to make the components, they are still cause very little pollution. Once they have been manufactured they’ll be able to keep producing energy indefinitely. Plus the forms of energy don’t have to come from unstable countries.

Solar Energy - Solar energy from the sun can easily be converted into sunlight and is now now-well understood process. The beams of light from the sun hit a photovoltaic (PV) module which responds by generating a current. This electrical energy is then carried into our homes by wires and circuit breakers.

Wind Energy - Although completely different from solar, there are some similarities. The wind blows the propeller which is on a shaft surrounded by a magnet wrapped by a coil of wire. Either the magnet turns near the wire or the wire turns causing electrons in the wire to experience force. The force causes the electrons to move along the wire causing what we call an electrical current.

The methods are simple. Sun and wind cost nothing. There are problems however; it does cost money to convert the energy into a usable form, plus there are some physical limitations along with engineering difficulties.

Costs - First of all there are costs involved in order to produce a PV module or wind turbine. Then there is the cost of transportation and installation. Plus at the moment they aren’t as cost-effective as the more traditional forms of producing energy such as oil or coal.

Although technology is constantly improving, they don’t produce as much power as other forms for the same cost.

Efficiency - If the solar panel is placed on the equator, 1,00 watts per square meter of solar energy is obtained. However if the panels are further away from the equator and it is a dull day, then the watts obtained are reduced to about 125-375 W/m2. Then you need to take into consideration the efficiency. With a solar-powered PVmodule you’ll get 10-15% efficiency depending on how it’s made.

Despite this, having solar panels covering your roof will give you enough energy to power the electricity in your home, as long as you are careful about usage.

Problems with Wind Power - Engineers want to place wind turbines where it is windiest in order to obtain the most energy. Unfortunately many of the windiest locations are inhabited by many species of bird. If a bird flies into a turbine it will kill them.

If there is a lack of wind, the turbines cannot function. They also need to be connected to a storage system and they don’t give out as much power as it would be liked.

Despite the drawbacks that solar and wind energy has, they are an essential part of our future if we want to reduce our dependency on oil and reduce air pollution. As technology improves, an increase in efficiency can be expected along with reduced costs. It may however be some time before we can rely on them 100% of our energy needs.

Related Entries:

* Is Solar Power Worth it? - Solar power may have many benefits but with costs ranging anywhere between a few thousand dollars to $50,000 or more it’s worthwhile reading up as much as you can on the subject. Sunlight Levels - One serious consideration is the amount of sunlight you enjoy where you live. If you’re lucky to live somewhere sunny like
* Is Renting You Solar Panels a Feasible Option - Although most people love the idea of having solar panels to generate their own power, one of the main things that put them off is the initial costs. In order to power the average home you’ll need pretty large solar panels. Solar panel systems typically cover the whole of the south-facing roof in order to
* Solar Roof Shingles - With so many people concerned about our impact on planet Earth, it’s no wonder that renewable energy has become so popular. One way that you can do your bit for the environment is to have solar panels fitted to your roof which then take the energy from the sun so that you can use
* Environmentally Friendly Solar Powered Water Heaters - If you’re looking to replace your current water heater you will find that there are a number of different options available to you. Although the most common types are gas and electric, you should also consider the benefits of buying a solar water heater too. Unfortunately they do tend to cost more money to begin
* Solar Powered Attic Fans and Vents - If you have an attic and you are keen on using renewable energy as much as possible, then you should look into buying an attic fan or vent. Besides being eco friendly, one of the major benefits of using solar power is that fact that the energy is taken from the sun.

Photovoltaic vs Photosynthetic vs Solar thermal energy vs Photoconductivity

2008-12-09T03:26:00.000-08:00

Photovoltaic vs. Photosynthetic Solar Energy

As of yet few quantum physicists have actually written philosophical papers on the political implications of photochemical solar cells. While they remain in the laboratories, predictions have been set that within three to five years, they will become a more aesthetic approach to solar energy generation with the same, if not better conductivity levels as current photovoltaics. Basically, its high-tech competition.

So what is a photosynthetic solar energy cell, how does it compete with the photovoltaic market and what kind of implications would that have on our society? Good question, but not so easy to answer. Photosynthesis is every outdoor school kids most important discovery, and as early as the sixth grade people get the idea about converting sunlight into sugars, but how can chlorophyll be synthesized and conductive to electrons, thereby creating a usable current? By using photosynthetic proteins to convert light into electricity.

Academic research in the US on this subject has been top secret for years including such names as the Massachusetts Institute of Technology, the U.S. Naval Research Laboratory, and the University of Tennessee. By taking spinach leaf molecules or photosynthetic bacteria toconvert light into energy, a whole new kind of solar panel is now available to architects. Even better, it works and as Dr. Frankenstein once screamed in scientific delight, Its alive!

One of the most important researchers on this concept outside the U.S. wrote a paper called Supramolecular Photochemistry and Solar Cellswhich pretty much details all the legwork done so far on the subatomic level with microbiology and photochemistry. The world renown Chemistry professor and researcher at the University in São Paulo, Brazil Dr. Neyde Yukie Murakami Iha shows how some of her teams most outstanding studies have been fairing over the last decade or so, and keep on going non-stop.

Although Neyde herself would not be interested in commercializing this stuff to all of us, some of her peers in Japan have already taken the commercial risks. The so called PV-TV used as a skyscraper skin developed in 2003 for commercial use by the Tokyo-based MSK Corporation together with Kaneka Chemicals and Taiyo Industries for architecture, is a transparent solar panel that works, is cost effective, pays for itself and just may create a revolution in the European market sometime soon.

These panels are 980mm long and 950 mm wide, with a standard depth of 10-13mm thick. Both flexible or strengthened-glass options are available making it a transparent skin of virtually any pain-glass color you might be looking for with certain scientific restrictions thus far. Which colors exactly are less efficient still remains unclear, but the ones sold so far can act as a three-in-one glazing element, solar energy panel and video display screen.

Taiyo Industries has already been putting this skyscraper skin on buildings in Japan and in London since July of 2004. While the languagebarrier may be a little restrictive, the product itself offers enough advantages for the buyer that it becomes more than worth it. At $45 a square foot, the skin actually pays for itself after some years of usage, and helps get zero energy buildings farther along in the realm of practical, no-nonsense business.

For urbanism and architecture students, this is a thing to be looking into very soon. Not only is this skin economical and multi-functional, but creativity is one of its biggest advantages. Wanta skylight that will hold up to heavy rain, hail or even snow and still serve as a generator in the sunlight and impede ultraviolet rays? Sound good? What about a skin that can be both, a window and a outdoor bulletin board system at night, while stillholding out the intense summer heat, illuminating the offices, hallways, meeting rooms and still acting as a mirror during the day?

So why worry about conventional roofing, when a photosynthetic solar panel can offer natural lighting, keep heat out in thesummer and warm air in during the colder months while still acting as a natural form of skylight? Talk about sustainability! Just one thing is to be said, Its alive!

Solar thermal energy, or solar hot water, uses flat collector plates to harness the sun’s energy to heat water for use in businesses, homes, and pools. The installation and appearance are much like those of the PV panel, and the collectors are best installed facing south, under unobstructed sunlight. Unlike PV panels, solar thermal collectors do not convert sunlight to electricity, but transfer the energy directly to the water. Solar thermal systems displace the electricity or natural gas that would otherwise be required to heat water. Federal tax credits are available for most solar hot water systems, but cannot be used for systems that heat swimming pools or hot tubs. State-funded solar thermal incentives are not yet available outside of a pilot program in San Diego.

Photoconductivity is an optical and electrical phenomenon in which a material becomes more conductive due to the absorption of electro-magnetic radiation such as visible light, ultraviolet light, infrared light, or gamma radiation. Lead content of the surrounding area can be a factor in the effectiveness of this, however. When light is absorbed by a material like a semiconductor, the number of free electrons and holes changes and raises the electrical conductivity of the semiconductor. To cause excitation the light that strikes the semiconductor must have enough energy to raise electrons across the forbidden bandgap or by exciting the impurities within the bandgap. When a bias voltage and a load resistor are used in series with the semiconductor, a voltage drop across the load resistors can be measured when the change in electrical conductivity varies the current flowing through the circuit. Two classic examples of photoconductive materials are the polymer polyvinylcarbazole, which is used extensively in photocopying (xerography); and lead sulfide, used in infrared detection applications, such as the U.S. Sidewinder and Russian Atoll heat-seeking missiles and selenium, as employed in early television and xerography experiments.

Why Solar Cell so Expensive

2008-12-09T02:55:00.000-08:00

Most solar cells (the best ones) are made from silicon crystal that is grown very slowly. Silicon crystals growth from pure silicon is an extremely slow and expensive process.
Because of gravity and how the crystals are grown it is very hard to grow large flawless crystals.
The biger the crystal the harder it is to make it perfectly flawless, a requirement for it to work.
Pure silicon crystal ingots are very expensive items flawless or not. I'm not sure what it runs but it is likely to be more expensive that gold ingots.
Fortunately, most chips are small and one waffer which is a very thin slice from an ingot can make thousands of chips, but only one solar cell. There are new types of solar cells now that
do not cost so much...but the technology is new and the cost has not come down yet. Here is an example that uses nanostructure diamonds of all things: http://www.advanceddiamond.com/
Source:
http://www.solaicx.com/
http://www.solarworld.de/

One reason is that silicon is in limited supply. Until better means of producing it are discovered and developed, it will be of limited supply and increasing demand. However, some state Governments and also the federal government have started to provide subsidies to help with the initial investment which is expected to take 10-15 years to recoup. Also, 42 states and D.C. require utilities companies to pay you for any excess power that you generate and sell to them.

And because of the failure rate of making the cells. They are fragile to begin with, and assembly makes the problems worse. There is also the point of supply and demand. If there is a high demand for a product, then the price goes up for the item, like gasoline.

The purity of semiconductor photovoltaic materials (e.g. silicon) must be very high to produce efficient solar cells. It is true that the PV industry has benefited from the computer industry in the development of large-scale processes for preparing pure and highly crystalline feedstock. However, the value of silicon is artificially inflated because of the high cost/value of computer chips. The value of a commodity, whether it be silicon, gold, or cattle, is nominally proportional to the scarcity of that material, but it also depends on demand for the finished product. Computer chips sell for $500-1000. Since you need the same grade of silicon to make solar cells, it's hard to make them for a penny a piece. Single-crystal silicon wafers are also made using a batch process, which is inherently more expensive than a continuous process. Newer techniques to produce amorphous silicon panels has had some success at lowering the cost of solar panels. Keep in mind that the material has to be doped with trace amounts of certain elements to produce an n-p junction. Photovoltaic panels generate a DC current, just like a battery, but with light instead of chemical energy. Like the battery, the n-p junction gives the panel a positive and negative side which directs the flow of current. Controlling and optimizing the concentration of dopants in semiconducting materials is a black art, unto itself.
A number of materials such as gallium arsenide and indium phosphide have been used to produce solar cells with greater efficiency than silicon, but these materials are even more expensive to manufacture.
One of the hot fields to watch out for is thin-film solar cells. Traditionally, photovoltaic materials are grown in reactors at high temperatures and near vacuum conditions. Cadmium sulfide and copper indium diselenide can be deposited at low temperatures onto flexible, light-weight polymer sheets. Due to natural "defects" in the crystal structure of these compounds, CdS/CIS forms a natural n-p junction, which eliminates the need to add dopants to the materials. A continuous roll-to-roll process can also be used to make hundreds of feet of solar panel at a time. Right now the efficiencies of these thin-film solar panels are relatively low, but they are cheap as dirt to make.
It will still be awhile before you see them in wide-spread use, due in large part to the low cost of fossil fuels and advances in battery technologies. Developments in niche markets where it is more practical to use panels (such as in portable devices and in remote facilities) than other power sources will see some of the first applications. There is also a lot of interest in light-weight flexible panels for space-based applications. It costs in the neighborhood of $10,000/pound to place a payload in space and there is only so much room in the nosecone of a rocket. A large panel of thin-film material could be rolled up into the space of a rigid solar panel and measure a fraction of the weight.

So there are a variety of interdependent issues which control costs You have to take all these things into consideration when you are looking at the big picture. Diesel fuel is a much lower grade of petroleum then the unleaded gasoline that you put in your car, but it typically costs more at the pump because of lower demand for diesel. Until the cost of fossil fuels goes up and/or demand for alternative energy sources increases, the solar industry won't be able to exploit the full benefit of mass production cost-savings.

A while back I wrote about people innovating in the web space for solar, where I mentioned how I had a beef with the way the media portrays new solar energy technology. Here’s why:

First, they always understate time frames and cost, and overstate benefits. Read this. It’s just an example, but there are hundreds of these types of articles written each week, and they make my skin crawl. The article leaves you feeling as though a revolutionary startup is going to have $1/watt solar panels on your doorstep next week. They’re not.

* Will they be able to PRODUCE solar panels for $1/watt at some point? Possibly, some day a long time from now. Will they be able to meet demand and distribution problems on the day they meet that production price point? Probably not. Will they sell them for $1/watt? NO, they will cost more, that’s how companies make money. Will the distributors resell them for the same price? No, or they would go broke too. Will it cost $1/watt for installers to put them in? No, it will cost more. In fact, if the panels were available TODAY, my (totally off the cuff) guess is you are looking at something like $6/watt, turnkey.
* Will they work on homes? Probably not. Initial applications will be commercial applications with large roofs. Homes with small roofs will need highly efficient panels to capitalize on that space. The best thin film you can get out there at the moment is going to require four times the space to get the same power out of it. That is simply not an option for homes. That is why no one is installing the stuff on houses right now, and it doesn’t look like we will be anytime soon. Ironically, the article makes it sound as though it will be more efficient than current photovoltaic panels, which is ludicrous.

And another thing. We’re in a subsidy sweet spot, in many places, including here in California. The federal tax credit on solar energy, as it stands, is gone at the end of 08′. The California Solar Initiative, our state-wide subsidy, steps down in 30 cent/watt steps as more people install solar. Add that to the rising production costs of solar, this space age product, whenever it comes out, may end up costing you the same as installations do now. And by then you’ve paid another 80 months of power bills.

That’s right, you heard me correctly. Solar is getting more expensive. The price of energy has increased the cost to manufacture solar panels. Additionally, many are made in Asia and must be shipped over, and shipping costs have exploded. Finally, heavy demand in places like Spain and Germany, due to their excellent, forward thinking subsidies has caused a lot of local distributors to ship overseas.

For the company I work for, our products cost substantially more per watt than they did last year, and that trend is going to continue. Are breakthroughs in solar energy technology that allow for much cheaper production that will also work in residential applications going to be employed at some point? Yes. But it’s way longer into the future than the media would lead you to believe, and solar energy is cost effective right now. If you get a PV system on your roof, and 15 years later some flexo-thin film product is available at half price, you’ll still have the last laugh, and you will have been energy independent for those 20 years.

Germany Reconsidering their Awesome Solar Subsidy Program
THALHEIM, Germany — This sad stretch of eastern Germany, with its deserted coal mines and corroded factories, epitomizes post-industrial gloom. It is a place where even the clouds rarely seem to part.
Yet the sun was shining here the other day — and nowhere more brightly than at Q-Cells, a German company that surpassed Sharp last year to become the world’s largest maker of photovoltaic solar cells. Q-Cells is the main tenant among a flowering cluster of solar start-ups here in an area known as Solar Valley.

Thanks to its aggressive push into renewable energies, cloud-wreathed Germany has become an unlikely leader in the race to harness the sun’s energy. It has by far the largest market for photovoltaic systems, which convert sunlight into electricity, with roughly half of the world’s total installations. And it is the third-largest producer of solar cells and modules, after China and Japan.

Now, though, with so many solar panels on so many rooftops, critics say Germany has too much of a good thing — even in a time of record oil prices. Conservative lawmakers, in particular, want to pare back generous government incentives that support solar development. They say solar generation is growing so fast that it threatens to overburden consumers with high electricity bills.

Solar-energy entrepreneurs warn that reducing incentives will deprive Germany of its pole position in an industry of the future. As proof, they point to the United States and Japan, which were once solar stars but have faded as their government subsidies became less enticing.

The debate over solar subsidies is a test of how an environmentally minded country can move from nurturing a promising alternative energy sector to creating a mass-market industry that can compete with conventional energy sources on its own footing. It is a tricky transition, even with a sympathetic population.

“Germany’s law has basically been a turbocharger,” said Anton Milner, the chief executive of Q-Cells. If the proposals being floated by the Christian Democratic Union, the party of Chancellor Angela Merkel, were adopted, he predicted, “you’d kill the industry.”

Germany’s surging market has lured investors from Canada, Norway and the United States. More than 40,000 people work in the photovoltaic industry, helping to revive blighted regions like this one. On Wednesday, Q-Cells reported a 63 percent jump in its first-quarter operating profit, showing the riches to be reaped from sunshine.

Leading a visitor past gleaming rows of solar panels on the roof of Q-Cells’ headquarters, Mr. Milner, a British-born former executive at Royal Dutch Shell, said Germany could not afford to blow this chance. Surely, he says, the naysayers are aware that the cost of electricity will spike along with the price of fossil fuels?

Joachim Pfeiffer, a member of Parliament who is drafting the plan to cut incentives, said: “We don’t want to slaughter the solar industry; we think photovoltaic technology will have a great future. But to have that future, we can’t have overkill now.”

At the heart of the debate is the Renewable Energy Sources Act. It requires power companies to buy all the alternative energy produced by these systems, at a fixed above-market price, for 20 years.

This mechanism, known as a feed-in tariff, gives entrepreneurs a powerful incentive to install solar panels. With a locked-in customer base for their electricity, they can earn a reliable return on their investment. It has worked: homeowners rushed to clamp solar panels on their roofs and farmers planted them in fields where sheep once grazed.

The amount of electricity generated by these installations rose 60 percent in 2007 compared with 2006, faster than any other renewable energy (solar still generates just 0.6 percent of Germany’s total electricity, compared with 6.4 percent for wind).

This, in a country that gets an average of only 1,528 hours of sunshine a year, less than a third of the total daylight hours. That figure is comparable to London’s but it is one-third fewer sunshine hours than in Florence, Italy, and only half San Diego’s, making German solar installations less efficient, and their growth all the more remarkable.

With wind, biomass and other alternative energy also growing, Germany derives 14.2 percent of its electricity from renewable sources. That puts it ahead of a European Union target for countries to generate 12.5 percent of electricity from alternative sources by 2010.

Spain, France, Italy and Greece have copied Germany’s solar incentives. In California, Gov. Arnold Schwarzenegger pushed a plan in which utilities pay rebates to customers with solar panels, though only up to the amount of electricity they would have otherwise used from conventional energy sources.

“Germany is a driving force worldwide,” said Hermann Scheer, a member of Parliament who helped write the law. “It is very important that the driving force not become a lame duck.”

Christian Democrats, however, say the law has been too successful for its own good. Utilities, they note, are allowed to pass along the extra cost of buying renewable energy to customers, and there is no cap on the capacity that can be installed — as exists in other countries to prevent subsidies from mushrooming.

At the moment, solar energy adds 1.01 euros ($1.69) a month to a typical home electricity bill, a modest surcharge that Germans are willing to pay. That will increase to 2.14 euros a month by 2014, according to the German Solar Energy Association.

But the volume of solar-generated energy is rising much faster than originally predicted, and critics contend that the costs will soar. Mr. Pfeiffer, the legislator, said solar power could end up adding 8 euros ($12.32) to a monthly electricity bill, which would alienate even the most green-minded. With no change in the law, he says, the solar industry will soak up 120 billion euros ($184 billion) in public support by 2015.

The conservatives would like to accelerate the rate at which the feed-in tariff declines, now set at 5 percent a year. Under a draft proposal, the tariff would fall 30 percent in 2009, and 9 percent a year after that. The law’s term might also be shortened to 15 years from 20.

Mrs. Merkel, who boasts of her green credentials, has yet to enter the debate. Her party must win over its coalition partner, the Social Democratic Party, which might be tough, given that the law was strengthened in 2004 by the last government, led by the Social Democrats.

Meanwhile, solar advocates are testifying before Parliament and publishing articles defending the law.

Eicke R. Weber, a prominent physicist, said the estimate of 120 billion euros in subsidies was too high because it did not take into account the rising price of conventional electricity. That, plus a gradual decline in the cost of solar, will close the price gap between conventional and solar-generated electricity by 2014 or 2015, he predicted.

The actual subsidy, Mr. Weber said, will be 40 billion to 60 billion euros, a third of what the German state is paying to prop up its superannuated coal industry.

“If we’re willing to burden the population with 180 billion euros of support for a dying industry, who do we worry about taking one-third of this to make Germany the world leader in photovoltaic technology?” said Mr. Weber, director of the Fraunhofer Institute for Solar Energy Systems in Freiburg.

Defenders of solar energy see the hand of Germany’s power companies behind the effort to change the law. Reducing incentives for solar would favor wind, which is a more natural fit for the utilities, since the cost of building wind farms is too high for the average homeowner with an empty roof and an urge to generate electricity.

“Solar energy is more decentralized, so the industry sees more competition from solar than from wind,” said Carsten Körnig, the managing director of the German Solar Energy Association.

In the former East Germany, where scores of state-subsidized industries were shuttered after reunification in 1990, the solar industry is a welcome tonic for a depressed region. Signet Solar, an American maker of photovoltaic modules that use thin-film technology, chose to build its first factory and research center near Dresden.

“We decided right from the beginning to have our main R&D in Germany,” said Gunter Ziegenbalg, Signet’s managing director.

Still, there are constant reminders of how quickly Germany could lose its status. Signet is building its next factory in Madras, India; Q-Cells is building one in Malaysia. Other German companies are exploring the Mediterranean markets, particularly Spain.

With more sunny days a year, Spain is likely to have a competitive solar industry that can stand on its feet before Germany’s does. And now it has put in place its own German-style incentives.

“To develop a technology, you’ve got to create an industry,” said Mr. Milner, the chief executive of Q-Cells, referring to the German success story. “You can wait and wait and wait for costs to come down, but it takes too long.”

Free Energy Machine. Does it True or Fake ?

2008-12-01T02:16:00.000-08:00

Here are list of Them :

Perpetual Engine

The Fuelless Engine

The Fuelless Heater

The Gravity Motor

The Air Engine

Tesla Turbine

Water subtitute Oil

Wind Turbine (Wikipedia Version)

2008-12-01T02:01:00.000-08:00

A wind turbine is a rotating machine which converts the kinetic energy in wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill. If the mechanical energy is then converted to electricity, the machine is called a wind generator, wind turbine, wind power unit (WPU), wind energy converter (WEC), or aerogenerator.

This article discusses electric power generation machinery. Windmill discusses machines used for grain-grinding, water pumping, etc. The article on wind power describes turbine placement, economics and public concerns. The wind energy section of that article describes the distribution of wind energy over time, and how that affects wind-turbine design. See environmental concerns with electricity generation for discussion of environmental problems with wind-energy production.

Wind turbines near Aalborg, Denmark. For scale, a normally-sized doorway can be seen at the base of the pylon.

History

Main article: History of wind power

The world's first megawatt wind turbine at Castleton, Vermont

Wind machines were used in Persia as early as 200 B.C. This type of machine was introduced into the Roman Empire by 250 A.C. However, the first practical windmills were built in Sistan, Iran, from the 7th century. These were vertical axle windmills, which had long vertical driveshafts with rectangle shaped blades.^[1] Made of six to twelve sails covered in reed matting or cloth material, these windmills were used to grind corn and draw up water, and were used in the gristmilling and sugarcane industries.^[2]

By the 14th century, Dutch windmills were in use to drain areas of the Rhine River delta. In Denmark by 1900 there were about 2500 windmills for mechanical loads such as pumps and mills, producing an estimated combined peak power of about 30 MW. The first known electricity generating windmill operated was a battery charging machine installed in 1887 by James Blyth in Scotland, UK^{[citation needed]}. The first windmill for electricity production in the United States was built in Cleveland, Ohio by Charles F Brush in 1888, and in 1908 there were 72 wind-driven electric generators from 5 kW to 25 kW. The largest machines were on 24 m (79 ft) towers with four-bladed 23 m (75 ft) diameter rotors. Around the time of World War I, American windmill makers were producing 100,000 farm windmills each year, most for water-pumping.^[3] By the 1930s windmills for electricity were common on farms, mostly in the United States where distribution systems had not yet been installed. In this period, high-tensile steel was cheap, and windmills were placed atop prefabricated open steel lattice towers.

A forerunner of modern horizontal-axis wind generators was in service at Yalta, USSR in 1931. This was a 100 kW generator on a 30 m (100 ft) tower, connected to the local 6.3 kV distribution system. It was reported to have an annual capacity factor of 32 per cent, not much different from current wind machines.^[4]

The first utility grid-connected wind turbine operated in the UK was built by the John Brown Company in 1954 in the Orkney Islands. It had an 18 meter diameter, three-bladed rotor and a rated output of 100 kW.

Potential turbine power

Main article: Wind turbine design

Wind Turbine Power Coefficient

The amount of power transferred to a wind turbine is directly proportional to the area swept out by the rotor, to the density of the air, and the cube of the wind speed.

The power $P$ in the wind is given by:

where P = power in watts., α = an efficiency factor determined by the design of the turbine, ρ = mass density of air in kilograms per cubic meter, r = radius of the wind turbine in meters, and v = velocity of the air in meters per second.^[5]

As the wind turbine extracts energy from the air flow, the air is slowed down which causes it to spread out. Albert Betz, a German physicist, determined in 1919 (see Betz' law) that a wind turbine can extract at most 59% of the energy that would otherwise flow through the turbine's cross section, that is α can never be higher than 0.59 in the above equation. The Betz limit applies regardless of the design of the turbine.

This equation shows the effects of the mass rate of flow of air traveling through the turbine, and the energy of each unit mass of air flow caused by its velocity. As an example, on a cool 15 °C (59 °F) day at sea level, air density is 1.225 kilograms per cubic metre. An 8 m/s (28.8 km/h or 18 mi/h) breeze blowing through a 100 meter diameter rotor would move almost 77,000 kilograms of air per second through the swept area. The total power of the example breeze through a 100 meter diameter rotor would be about 2.5 megawatts. Betz' law states that no more than 1.5 megawatts could be extracted.

Types of wind turbines

Wind turbines can be separated into two types based by the axis in which the turbine rotates. Turbines that rotate around a horizontal axis are more common. Vertical-axis turbines are less frequently used.

Horizontal axis

Components of a horizontal axis wind turbine (gearbox, rotor shaft and brake assembly) being lifted into position

Horizontal-axis wind turbines (HAWT) have the main rotor shaft and electrical generator at the top of a tower, and must be pointed into the wind. Small turbines are pointed by a simple wind vane, while large turbines generally use a wind sensor coupled with a servo motor. Most have a gearbox, which turns the slow rotation of the blades into a quicker rotation that is more suitable to drive an electrical generator.^[6]

Since a tower produces turbulence behind it, the turbine is usually pointed upwind of the tower. Turbine blades are made stiff to prevent the blades from being pushed into the tower by high winds. Additionally, the blades are placed a considerable distance in front of the tower and are sometimes tilted up a small amount.

Downwind machines have been built, despite the problem of turbulence, because they don't need an additional mechanism for keeping them in line with the wind, and because in high winds, the blades can be allowed to bend which reduces their swept area and thus their wind resistance. Since turbulence leads to fatigue failures, and reliability is so important, most HAWTs are upwind machines.

HAWT Subtypes

Doesburger windmill, Ede, The Netherlands.

There are several types of HAWT:

12th-century windmills

These squat structures, typically (at least) four bladed, usually with wooden shutters or fabric sails, were developed in Europe. These windmills were pointed into the wind manually or via a tail-fan and were typically used to grind grain. In the Netherlands they were also used to pump water from low-lying land, and were instrumental in keeping its polders dry.

In Schiedam, the Netherlands, a traditional style windmill (the Noletmolen) was built in 2005 to generate electricity.^[7] The mill is one of the tallest Tower mills in the world, being some 42.5 metres (139 ft) tall.

19th-century windmills

The Eclipse windmill factory was set up around 1866 in Beloit, Wisconsin and soon became successful building mills for pumping water on farms and for filling railroad tanks. Other firms like Star, Dempster, and Aeromotor also entered the market. Hundreds of thousands of these mills were produced before rural electrification and small numbers continue to be made.^[3] They typically had many blades, operated at tip speed ratios (defined below) not better than one, and had good starting torque. Some had small direct-current generators used to charge storage batteries, to provide power to lights, or to operate a radio receiver. The American rural electrification connected many farms to centrally-generated power and replaced individual windmills as a primary source of farm power by the 1950s. They were also produced in other countries like South Africa and Australia (where an American design was copied in 1876^[8]). Such devices are still used in locations where it is too costly to bring in commercial power.

Modern wind turbines

Three bladed wind turbine

Turbines used in wind farms for commercial production of electric power are usually three-bladed and pointed into the wind by computer-controlled motors. These have high tip speeds of up to six times the wind speed, high efficiency, and low torque ripple, which contribute to good reliability. The blades are usually colored light gray to blend in with the clouds and range in length from 20 to 40 metres (65 to 130 ft) or more. The tubular steel towers range from 200 to 300 feet (60 to 90 metres) tall. The blades rotate at 10-22 revolutions per minute.^[9]^[10] A gear box is commonly used to step up the speed of the generator, although designs may also use direct drive of an annular generator. Some models operate at constant speed, but more energy can be collected by variable-speed turbines which use a solid-state power converter to interface to the transmission system. All turbines are equipped with shut-down features to avoid damage at high wind speeds.

HAWT advantages

Variable blade pitch, which gives the turbine blades the optimum angle of attack. Allowing the angle of attack to be remotely adjusted gives greater control, so the turbine collects the maximum amount of wind energy for the time of day and season.
The tall tower base allows access to stronger wind in sites with wind shear. In some wind shear sites, every ten meters up, the wind speed can increase by 20% and the power output by 34%.

HAWT disadvantages

Turbine blade convoy passing through Edenfield in the UK

HAWTs have difficulty operating in near ground, turbulent winds.
The tall towers and blades up to 90 meters long are difficult to transport. Transportation can now cost 20% of equipment costs.
Tall HAWTs are difficult to install, needing very tall and expensive cranes and skilled operators.
Massive tower construction is required to support the heavy blades, gearbox, and generator.
Reflection on tall HAWTs may affect side lobs of radar installations creating signal clutter, although filtering can suppress it.
Their height makes them obtrusively visible across large areas, disrupting the appearance of the landscape and sometimes creating local opposition.
Downwind variants suffer from fatigue and structural failure caused by turbulence.
HAWTs require an additional yaw control mechanism to turn the blades toward the wind.

[edit] Cyclic stresses and vibration

Cyclic stresses fatigue the blade, axle and bearing; material failures were a major cause of turbine failure for many years. Because wind velocity often increases at higher altitudes, the backward force and torque on a horizontal-axis wind turbine (HAWT) blade peaks as it turns through the highest point in its circle. The tower hinders the airflow at the lowest point in the circle, which produces a local dip in force and torque. These effects produce a cyclic twist on the main bearings of a HAWT. The combined twist is worst in machines with an even number of blades, where one is straight up when another is straight down. To improve reliability, teetering hubs have been used which allow the main shaft to rock through a few degrees, so that the main bearings do not have to resist the torque peaks.

When the turbine turns to face the wind, the rotating blades act like a gyroscope. As it pivots, gyroscopic precession tries to twist the turbine into a forward or backward somersault. For each blade on a wind generator's turbine, precessive force is at a minimum when the blade is horizontal and at a maximum when the blade is vertical. This cyclic twisting can quickly fatigue and crack the blade roots, hub and axle of the turbines.

Water pumping rural windmill in Germany

Vertical axis

Vertical-axis wind turbines (or VAWTs) have the main rotor shaft arranged vertically. Key advantages of this arrangement are that the turbine does not need to be pointed into the wind to be effective. This is an advantage on sites where the wind direction is highly variable. VAWTs can utilize winds from varying directions.

With a vertical axis, the generator and gearbox can be placed near the ground, so the tower doesn't need to support it, and it is more accessible for maintenance. Drawbacks are that some designs produce pulsating torque. Drag may be created when the blade rotates into the wind.

It is difficult to mount vertical-axis turbines on towers, meaning they are often installed nearer to the base on which they rest, such as the ground or a building rooftop. The wind speed is slower at a lower altitude, so less wind energy is available for a given size turbine. Air flow near the ground and other objects can create turbulent flow, which can introduce issues of vibration, including noise and bearing wear which may increase the maintenance or shorten the service life. However, when a turbine is mounted on a rooftop, the building generally redirects wind over the roof and this can double the wind speed at the turbine. If the height of the rooftop mounted turbine tower is approximately 50% of the building height, this is near the optimum for maximum wind energy and minimum wind turbulence.

VAWT subtypes

30 m Darrieus wind turbine in the Magdalen Islands

Darrieus wind turbine: "Eggbeater" turbines. They have good efficiency, but produce large torque ripple and cyclic stress on the tower, which contributes to poor reliability. Also, they generally require some external power source, or an additional Savonius rotor, to start turning, because the starting torque is very low. The torque ripple is reduced by using three or more blades which results in a higher solidity for the rotor. Solidity is measured by blade area over the rotor area. Newer Darrieus type turbines are not held up by guy-wires but have an external superstructure connected to the top bearing.

Giromill: A subtype of Darrieus turbine with straight, as opposed to curved, blades. The cycloturbine variety has variable pitch to reduce the torque pulsation and is self-starting [1]. The advantages of variable pitch are: high starting torque; a wide, relatively flat torque curve; a lower blade speed ratio; a higher coefficient of performance; more efficient operation in turbulent winds; and a lower blade speed ratio which lowers blade bending stresses. Straight, V, or curved blades may be used. Recently, this type of turbine has been advanced by former Russian rocket scientists who claim to have increased the efficiency of the VAWT up to 38%. A company, SRC Vertical Ltd.[2], has been formed, and has begun selling the new turbine.

A helical twisted VAWT.

Savonius wind turbine: These are drag-type devices with two (or more) scoops that are used in anemometers, Flettner vents (commonly seen on bus and van roofs), and in some high-reliability low-efficiency power turbines. They are always self-starting if there are at least three scoops. They sometimes have long helical scoops to give a smooth torque. The Alvin Benesh rotor and the Hamid Rahai rotor improve efficiency with blades shaped to produce significant lift as well as drag.

12 m Windmill with rotational sails in Osijek, Croatia

VAWT advantages

No massive tower structure is needed.
As the rotor blades are vertical, no yaw mechanism is needed.
A VAWT can be located nearer the ground, making it easier to maintain the moving parts.
VAWTs have a higher airfoil pitch angle, giving improved aerodynamics while decreasing drag at low and high pressures.
Straight bladed VAWT designs with a square or rectangular cross-section have a larger swept area for a given diameter than the circular swept area of HAWTs.
VAWTs have lower wind startup speeds than HAWTs. Typically, they start creating electricity at 6 m.p.h. (10 km/h).
VAWTs usually have a lower tip speed ratio and so are less likely to break in high winds.
VAWTs may be built at locations where taller structures are prohibited.
VAWTs situated close to the ground can take advantage of locations where mesas, hilltops, ridgelines, and passes funnel the wind and increase wind velocity.
VAWTs do not need to turn to face the wind if the wind direction changes.
VAWT blades are easily seen and avoided by birds.
Most VAWTs start easily and do not require energy to begin turning.

VAWT disadvantages

Most VAWTs produce energy at only 50% of the efficiency of HAWTs in large part because of the additional drag that they have as their blades rotate into the wind. Versions that reduce drag produce more energy, especially those that funnel wind into the collector area.
VAWTs will rotate faster in stronger winds at higher elevations as they rotate at least as fast as the wind velocity.
A VAWT that uses guy-wires to hold it in place puts stress on the bottom bearing as all the weight of the rotor is on the bearing. Guy wires attached to the top bearing increase downward thrust in wind gusts. Solving this problem requires a superstructure to hold a top bearing in place to eliminate the downward thrusts of gust events in guy wired models.
While VAWTs' parts are located on the ground, they are also located under the weight of the structure above it, which can make changing out parts nearly impossible without dismantling the structure if not designed properly.

Wind turbines on the Lake Erie shore at Lackawanna, New York

Locations

Main article: Wind power

Wind turbines can also be classified by the location in which they are to be used. Onshore, offshore, or even aerial wind turbines have unique design characteristics, which are explained in more detail in section on turbine design and construction.

Turbine design and construction

Main article: Wind turbine design

Wind turbines are designed to exploit the wind energy that exists at a location. Aerodynamic modeling is used to determine the optimum tower height, control systems, number of blades, and blade shape.

Wind turbines convert wind energy to electricity for distribution. The turbine can be divided into three components. The rotor component, which is approximately 20% of the wind turbine cost, includes the blades for converting wind energy to low speed rotational energy. The generator component, which is approximately 34% of the wind turbine cost, includes the electrical generator, the control electronics, and most likely a gearbox component for converting the low speed incoming rotation to high speed rotation suitable for generating electricity. The structural support component, which is approximately 15% of the wind turbine cost, includes the tower and

Low temperature

Utility-scale wind turbine generators have minimum temperature operating limits which apply in areas that experience temperatures below –20 °C. Wind turbines must be protected from ice accumulation, which can make anemometer readings inaccurate and which can cause high structure loads and damage. Some turbine manufacturers offer low-temperature packages at a few percent extra cost, which include internal heaters, different lubricants, and different alloys for structural elements. If the low-temperature interval is combined with a low-wind condition, the wind turbine will require an external supply of power, equivalent to a few percent of its rated power, for internal heating. For example, the St. Leon, Manitoba project has a total rating of 99 MW and is estimated to need up to 3 MW (around 3% of capacity) of station service power a few days a year for temperatures down to –30 °C. This factor affects the economics of wind turbine operation in cold climates.

Special wind turbines

Main article: Special wind turbines

One E-66 wind turbine at Windpark Holtriem, Germany, carries an observation deck, open for visitors to see. Another turbine of the same type, with an observation deck, is located in Swaffham, England.

A series of lighter-than-air wind turbines are in development in Canada by Magenn Power. They deliver power to the ground by a tether system.^[12]

Wind turbines may also be used in conjunction with a large vertical solar updraft tower to extract the energy due to air heated by the sun. Or as part of wave powered generators where air displaced by waves drives turbines.^[13]

Variable pitch wind turbines are another special (yet low-cost) design. Designs such as the Jacobs are said to be inexpensive, highly efficient and usable in DIY-construction.^[14]

Small wind turbines

Main article: Small wind turbine

A small wind turbine being used at the Riverina Environmental Education Centre near Wagga Wagga, New South Wales, Australia

Small wind turbines may be as small as a fifty-watt generator for boat or caravan use. Small units often have direct drive generators, direct current output, aeroelastic blades, lifetime bearings and use a vane to point into the wind. Larger, more costly turbines generally have geared power trains, alternating current output, flaps and are actively pointed into the wind. Direct drive generators and aeroelastic blades for large wind turbines are being researched.

Record-holding turbines

The world's largest turbines are manufactured by the Northern German companies Enercon and REpower. The Enercon E-126 delivers up to 6 MW, has an overall height of 198 m (650 ft) and a diameter of 126 meters (413 ft). The Repower 5M delivers up to 5 MW, has an overall height of 183 m (600 ft) and has a diameter of 126 m (413 ft).

The turbine closest to the North Pole is a Nordex N-80 in Havøygavlen near Hammerfest, Norway. The ones closest to the South Pole are two Enercon E-30 in Antarctica, used to power the Australian Research Division's Mawson Station.^[15]

Matilda was a wind turbine located on Gotland, Sweden. It produced a total of 61.4 GWh in the 15 years it was active. That is more renewable energy than any other single wind power turbine had ever produced to that date. It was demolished on June 6th, 2008.

Criticisms

Wind turbines have very few impacts on the environment other than aesthetic effects, although VAWT designs are increasingly being designed with innovative artistic aesthetics.^{[citation needed]}

Wind Turbine Syndrome is a clinical phenomenon first coined by Nina Pierpont. According to her research, some people, when living in close proximity to horizontal axis industrial wind turbines, are affected by low-frequency vibrations emanating from the turbine. VAWT do not lend themselves to this effect as they do not rotate faster than wind speed.

Build A Wind Generator Book
Learn how to build a wind generator with our fully detailed guide book. Simple easy to follow instructions that even our 12 year old son can follow. You can save money on your energy bills and get started with renewable energy in your home with the home.

Lets Go Green

Energy Saving Tips and Trick (newdream)

Simple things you can do:

Long-term energy saving investments:

Reducing your car's energy usage:

Convert your Oil Car to Electric Car

REVA Electric Cars (greenprophet)

Build Your Own Electric Car - Electric Car Plans - Electric Car Conversions

(build-electric-car)

Dear Friends,

You see our family is no different than yours. We are just regular people who just want to make a difference in their lives. We wanted to lower our electricity costs. We wanted to lower our car expenses. It is getting very expensive out there so we figured out a way to beat it.

Today we live 100% Off-Grid and drive Electric Vehicles.

Our home requires a lot of batteries to store energy from our solar panels and wind generators. It was always so expensive to buy new ones, we needed an alternative. Then...

One summer a few years ago a friend of ours told us about a special kind of battery that we could get used (for free) in nearly dead condition and how he had come up with a way to recondition them to nearly new. He had been doing it for years for his RV that had a large solar array on it.

What was so amazing was that these particular batteries had tremendous capacity. When we hooked them up it seemed like our home was always full of power to use. Where before we had to conserve our energy much more strictly to see us through especially cloudy or windless days.

I wanted to make an improvement to our property so I went to get a bunch more of these batteries. Then it hit me! As I was hauling them home in the bed of our pickup truck I thought: "Why not use these same batteries to convert our car to electric?" And that is just what we did...

Did I mention that I am no mechanic? Nearly flunked out of auto mechanics in high school. I just couldn't get it. But, electricity and batteries is somehow easier for me to understand. And it seems like everybody who has read these plans agrees.

We have done 3 conversions for friends and family so far, and decided to let the plans out to a few of our Off Grid Newsletter subscribers to see what they could do with them. And every one of them found they could do it too.

"Well, pound nails to build your house, maybe", they would say. "But, build your own Electric Car? Doubt it."

Nuclear ? That's The Last Option but Not Now

Just Another comparison (nuclearpowerprocon)

More Deep about NUCLEAR

An Open Letter to Physicists

Table of Contents

Biological Ignorance

Some Biological Effects

Nuclear Power Plants

A Rational Energy Policy

Footnotes

Long and interesting Debate between Nuclear Power vs Renewable Energy

If you truly understand the system, a simple elegant solution will be obvious.

If you don't have a simple elegant solution, then you don't understand the problem.

Reply From Derek

NUCLEAR Energy

renewable energy

Global Warming FACT! (512developing)

Green Design Concepts (512developing)

Ten Earth-Friendly Things (512developing)

8 types of Renewable energy (512developing)

PARABOLIC TROUGHS

SOLAR DISH

SOLAR POWER TOWER

Computer-controlled LED lamp (bitrot)

1. The hardware

2. The firmware

3. Desktop computer control

Seven Component Regulated LED Lamp (solorb)

Seven Component Regulated LED Lamp

Introduction

Specifications

Theory

Construction

Alignment

Use

Parts

How 9W LED Bulb Beat 70W Incandescent (treehugger)

LED Vs Traditional Flashlights(ezinearticles)

The Benefits of LEDs (powerlineleds)

LED Technology (Wiki)

History

Technology overview

Driving LEDs

Indicator LEDs

Alphanumeric LEDs

Lighting LEDs on mains

Lighting LEDs on low voltage

Comparison to other lighting technologies

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Challenges

Research and development

US

Department of Energy

National Institute of Standards and Technology

Photovoltaic vs Wind Turbine for Home

Photovoltaic vs Photosynthetic vs Solar thermal energy vs Photoconductivity

Photovoltaic vs. Photosynthetic Solar Energy

Why Solar Cell so Expensive

Free Energy Machine. Does it True or Fake ?

Wind Turbine (Wikipedia Version)

Contents