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With a fuel cell, chemicals constantly flow into the cell so it never goes dead -- as long as there is a flow of chemicals into the cell, the electricity flows out of the cell. Most fuel cells in use today use hydrogen and oxygen as the chemicals.

If you want to be technical about it, a fuel cell is an electrochemical energy conversion device. A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity.

get about a hundred of these "bad boys" cranking out a few hundred RPM's and you might have the sound of an alien attack.

If you do live along the coast, your personal property is rather expensive and you might not be able to afford the opportunity to afford the land, let alone a wind generator.

Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current

Modern wind turbines fall into two basic groups; the horizontal-axis variety, like the traditional farm windmills used for pumping water, and the vertical-axis design, like the eggbeater-style Darrieus model

wind farm, and generate bulk electrical power

Utility-scale turbines range in size from 50 to 750 kilowatts. Single small turbines, below 50 kilowatts

Wind energy is very abundant in many parts of the United States. Wind resources are characterized by wind-power density classes, ranging from class 1 (the lowest) to class 7 (the highest). Good wind resources (e.g., class 3 and above, which have an average annual wind speed of at least 13 miles per hour) are found in many locations (see United States Wind Energy Resource Map)

free, renewable resource, so no matter how much is used today, there will still be the same supply in the future

clean, non-polluting, electricity. Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases

higher initial investment than fossil-fueled generators. Roughly 80% of the cost is the machinery, with the balance being site preparation and installation.

Although wind power plants have relatively little impact on the environment compared to fossil fuel power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and birds and bats having been killed (avian/bat mortality) by flying into the rotors. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants

remote locations far from areas of electric power demand (such as cities)

alternative uses may be more highly valued than electricity generation. However, wind turbines can be located on land that is also used for grazing or even farming

Wind is a form of solar energy

The terms "wind energy" or "wind power

describe the process by which the wind is used to generate mechanical power or electricity.

Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current. Simply stated, a wind turbine is the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.

"Thus, the combination of expected growth in energy demand and the lower density of biomass imply that by 2050, biomass transport volumes will be greater than the current capacity of the entire energy and agricultural commodity infrastructure,

"For example, a large biofuel plant would require 16 to 20 tanker trucks or railcars per day to move the fuel to market, increasing both traffic and costs."

Advantages   Geothermal energy does not produce any pollution, and does not contribute to the greenhouse effect.

Once you've built a geothermal power station, the energy is almost free. It may need a little energy to run a pump, but this can be taken from the energy being generated.

The big problem is that there are not many places where you can build a geothermal power station. You need hot rocks of a suitable type, at a depth where we can drill down to them. The type of rock above is also important, it must be of a type that we can easily drill through.

Hazardous gases and minerals may come up from underground, and can be difficult to safely dispose of.

Is it renewable? Geothermal energy is renewable. The energy keeps on coming, as long as we don't pump too much cold water down and cool the rocks too much

iofuels are potentially carbon-neutral, because although carbon dioxide is released when we burn them, carbon dioxide is taken in by the plants as they grow. However, energy is needed to grow the crops, harvest them, and to process the results into usable products - and most of this energy will be from fossil fuels for farm machinery and power stations.

Biofuels are potentially carbon-neutral, because although carbon dioxide is released when we burn them, carbon dioxide is taken in by the plants as they grow. However, energy is needed to grow the crops, harvest them, and to process the results into usable products - and most of this energy will be from fossil fuels for farm machinery and power stations.

Producing biofuels from crops means using large amounts of land to grow those crops - that means less land for food production. We must be careful to strike a balance between crops ofr fuel and crops for food.

Producing biofuels from crops means using large amounts of land to grow those crops - that means less land for food production. We must be careful to strike a balance between crops ofr fuel and crops for food.

Algae - that's pond scum - are microscopic water plants. They reproduce and photosynthesise fast, and the algae are then filtered out of the water and the lipids (oils) are used to make biodiesel.

It is claimed that growing plants to make biofuels will take in that carbon dioxide again. But biologists tell us that forests are not 'the lungs of the planet' after all - they give out as much CO2 as they absorb as the plants respire. It seems that it's plant plankton in the oceans that takes in most CO2 and gives out most oxygen.

It takes huge areas of land in order to grow crops for biofuels, although making biofuels from algae does not have this problem

Biofuel production is closer to being carbon-neutral than using fossil fuels.

Is it renewable? Biofuels are renewable, we can plant more of the crops or grow more of the algae.

Compared to petroleum diesel, biodiesel combustion produces less sulfur oxides, particulate matter, carbon monoxide, and unburned and other hydrocarbons, but more nitrogen oxide.

Biofuels may be considered to be carbon-neutral because the plants that are used to make biofuels (such as corn and sugarcane for ethanol, and soy beans and palm oil trees for biodiesel) absorb CO2 as they grow and may offset the CO2 produced when biofuels are made and burned.

Growing plants for biofuels is controversial however, as the land, fertilizers, and energy used to grow biofuel crops could be used to grow food crops instead. Also, in some parts of the world, large areas of natural vegetation and forests have been cut down to grow sugar cane for ethanol and soybeans and palm-oil trees to make biodiesel.

Biomass — Renewable Energy from Plants and Animals Source: The National Energy Education Project (Public Domain) Source: The National Energy Education Project (Public Domain) Biomass is organic material made from plants

Biomass fuels provided about 4% of the energy used in the United States in 2010. Of this, about 46% was from wood and wood-derived biomass, 43% from biofuels (mainly ethanol),

Currently, although the technology required to harness tidal energy is well established, tidal power is expensive, and there is only one major tidal generating station in operation. This is a 240 megawatt (1 megawatt = 1 MW = 1 million watts) at the mouth of the La Rance river estuary on the northern coast of France

Tidal electricity can be used to displace electricity which would otherwise be generated by fossil fuel (coal, oil, natural gas) fired power plants, thus reducing emissions of greenhouse and acid gasses.

There is a high capital cost for a tidal energy project, with possibly a 10-year construction period.

Electricity can be generated by water flowing both into and out of a bay. As there are two high and two low tides each day, electrical generation from tidal power plants is characterized by periods of maximum generation every twelve hours, with no electricity generation at the six hour mark in between.

Tidal energy is a renewable source of electricity which does not result in the emission of gases responsible for global warming or acid rain associated with fossil fuel generated electricity. Use of tidal energy could also decrease the need for nuclear power, with its associated radiation risks. Changing tidal flows by damming a bay or estuary could, however, result in negative impacts on aquatic and shoreline ecosystems, as well as navigation and recreation.

Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.

idal energy is one of the oldest forms of energy used by humans. Indeed, tide mills, in use on the Spanish, French and British coasts, date back to 787 A.D.. Tide mills consisted of a storage pond, filled by the incoming (flood) tide through a sluice and emptied during the outgoing (ebb) tide through a water wheel. The tides turned waterwheels, producing mechanical power to mill grain. We even have one remaining in New York- which worked well into the 20th century. Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.

Natural current driven tidal generators can be built into the structure of existing bridges. These generators will involve virtually no aesthetic problems.

Tidal energy use may not be a big player in our energy future, but it can make a contribution.

The first study of large scale tidal power plants was by the US Federal Power Commission in 1924 which if built would have been located in the northern border area of the US state of Maine and the south eastern border area of the Canadian province of New Brunswick, with various dams, powerhouses and ship locks enclosing the Bay of Fundy and Passamaquoddy Bay (note: see map in reference). Nothing came of the study and it is unknown whether Canada had been approached about the study by the US Federal Power Commission.[10] There was also a report on the international commission in April 1961 entitled " Investigation of the International Passamaquoddy Tidal Power Project" produced by both the US and Canadian Federal Governments.