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Geothermal energy has been used for thousands of years in some countries for cooking and heating. It is simply power derived from the Earth's internal heat.This thermal energy is contained in the rock and fluids beneath Earth's crust. It can be found from shallow ground to several miles below the surface, and even farther down to the extremely hot molten rock called magma.These underground reservoirs of steam and hot water can be tapped to generate electricity or to heat and cool buildings directly.A geothermal heat pump system can take advantage of the constant temperature of the upper ten feet (three meters) of the Earth's surface to heat a home in the winter, while extracting heat from the building and transferring it back to the relatively cooler ground in the summer

There are three types of geothermal power plants: dry steam, flash, and binary. Dry steam, the oldest geothermal technology, takes steam out of fractures in the ground and uses it to directly drive a turbine. Flash plants pull deep, high-pressure hot water into cooler, low-pressure water. The steam that results from this process is used to drive the turbine. In binary plants, the hot water is passed by a secondary fluid with a much lower boiling point than water. This causes the secondary fluid to turn to vapor, which then drives a turbine. Most geothermal power plants in the future will be binary plants.

It can be extracted without burning a fossil fuel such as coal, gas, or oil. Geothermal fields produce only about one-sixth of the carbon dioxide that a relatively clean natural-gas-fueled power plant produces.

Tidal power is a means of electricity generation achieved by capturing the energy contained in moving water mass due to tides. Two types of energy can be extracted: kinetic energy of currents between ebbing and surging, and potential energy from the difference in height (or head) between high and low water marks.

Tidal power schemes do not produce energy 24 hours a day. A conventional design, in any mode of operation, would produce power for 6 to 12 hours in every 24 and will not produce power at other times

A fuel cell is a device that uses a source of fuel, such as hydrogen, and an oxidant to create electricity from an electrochemical process.

Most fuel cells in use today, however, use hydrogen and oxygen as the chemicals.

Although hydrogen is the most abundant element in the universe, it is difficult to store and distribute. Canisters of pure hydrogen are readily available from hydrogen producers, but as of now, you can't just fill up with hydrogen at a local gas station.

Wind farms can cause climate change, according to new research, that shows for the first time the new technology is already pushing up temperatures.

Usually at night the air closer to the ground becomes colder when the sun goes down and the earth cools. But on huge wind farms the motion of the turbines mixes the air higher in the atmosphere that is warmer, pushing up the overall temperature.

Because pure hydrogen does not occur naturally, it takes energy to manufacture it. There are different ways to manufacture it, such as, electrolysis and steam-methane reforming process.

In electrolysis, electricity is run through water to separate the hydrogen and oxygen atoms. This method can be used by using wind, solar, geothermal, hydro, fossil fuels, biomass, and many other resources.

The more natural methods of making electricity (wind, solar, hydro, geothermal, biomass), rather than fossil fuels, would be better used as to continue the environment-friendly process of the fuel. Obtaining hydrogen from this process is being studied as a viable way to produce it domestically at a low cost. Steam-methane reforming process extracts the hydrogen from methane. However, this reaction causes a side production of carbon dioxide and carbon monoxide which are greenhouse gases and contribute to global warming.

There have been studies that prove the many benefits of substituting fossil fuels (petroleum, etc) with biofuels such as biodiesel and ethanol. In its simplest sense, such biofuels are biodegradable which means they are derived from organic materials. They are naturally renewable. It can create numerous jobs since our own farmers can practically make them domestically. Consequently, our reliance on foreign sources of fossil fuels will be significantly reduced. Moreover, these biofuels emit nontoxic and cleaner emissions in comparison to traditional fuels. These alternative fuels also do not promote global warming, since the carbon they emit is taken back to the environment.

biofuel is far more simple and easy to use

Wind energy releases no pollution into the air or water, and does not contribute to global warming

"on average, each MWh of electricity generated in the U.S. results in the emission of 1,341 pounds of carbon dioxide (CO2)

his avoided CO2 equals over 1.8 million tons of carbon, enough to fill 180 trains, each 100 cars long, with each car holding 100 tons of carbon every year."

Fossil fuels—coal, oil, and natural gas—are America's primary source of energy, accounting for 85 percent of current US fuel use.

Many of the environmental problems our country faces today result from our fossil fuel dependence. These impacts include global warming, air quality deterioration, oil spills, and acid rain.

Over the last 150 years, burning fossil fuels has resulted in more than a 25 percent increase in the amount of carbon dioxide in our atmosphere.

Can Already Cost Under $.06 per Kilowatt Hour * Pneumatic devices, such as the oscillating water column (OWC), use wave motion to compress and decompress air, and drive a turbine. * Float-based devices utilise a buoyant float moving with the waves, reacting against a sea bed anchor in order to harness energy. * Spillover devices utilise wave height to replenish a reservoir of seawater, which runs a turbine. * Raft-type devices use the relative motion of adjacent rafts or pontoons to harness wave energy. * Moving-body devices articulate in the water, inducing motion, which may be used to drive a hydraulic motor.

Tidal stream devices extract energy from the diurnal flow of tidal currents (caused by the gravitational pull of the moon). Unlike wind and wave power, tidal streams offer entirely predictable output. However, as the lunar cycle is of around 25 hours’ duration, the timing of peak outputs differs by around an hour each day and tidal energy cannot be guaranteed at times of peak demand.

However, several large grid-connected demonstration projects are expected to enter the water in the near future. Tidal stream is thus a few years behind wave energy.

Like electricity, hydrogen is a secondary source of energy. It stores and carries energy produced from other resources (fossil fuels, water, and biomass).

ydrogen is the simplest element. Each atom of hydrogen has only one proton. It is also the most plentiful gas in the universe. Stars like the sun are made primarily of hydrogen. The sun is basically a giant ball of hydrogen and helium gases. In the sun's core, hydrogen atoms combine to form helium atoms. This process — called fusion — gives off radiant energy.

Hydrogen gas is so much lighter than air that it rises fast and is quickly ejected from the atmosphere. This is why hydrogen as a gas (H2) is not found by itself on Earth. It is found only in compound form with other elements. Hydrogen combined with oxygen, is water (H2O). Hydrogen combined with carbon forms different compounds, including methane (CH4), coal, and petroleum.

Tidal 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.

A tidal range of at least 7 m is required for economical operation and for sufficient head of water for the turbines

By converting the power of the sun into electricity, solar energy is clean, green, will never run out and, after the initial cost of the solar panels, is entirely free

The sun is constant – it will always be there and is therefore a reliable, utterly renewable source of energy.

As it does not rely on the burning of harmful fuels to generate electricity, solar power is non-polluting – it does not contribute to global warming or greenhouse gas emissions.

As gas prices rise and global warming becomes more pervasive, more people are using biofuels as a way to save money and decrease their consumption of fossil fuels.

Geothermal power plants, which use heat from deep inside the Earth to generate steam to make electricity. Geothermal heat pumps, which tap into heat close to the Earth's surface to heat water or provide heat for buildings.

At a geothermal power plant, wells are drilled 1 or 2 miles deep into the Earth to pump steam or hot water to the surface.

hot springs, geysers, or volcanic activity, because these are places where the Earth is particularly hot just below the surface.

Almost all biofuels used today cause more greenhouse gas emissions than conventional fuels if the full emissions costs of producing these “green” fuels are taken into account,

pollution spewing from a typical coal plant

3,700,000 tons of carbon dioxide (CO2), the primary human cause of global warming--as much CO2 as cutting down 161 million trees.

sulphur dioxide (SO2), which causes acid rain

solar energy is environmentally safe and does not contribute to pollution, acid rain, global warming, or smog. it is very dependable and lasts as long as the sun does-a couple billion years.