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In only one hour, the amount of energy that shines on the Earth equates to the amount used by the world's population in an entire year. Mankind has developed a way to utilize the sun's vast energy by converting its sunlight into electricity via photovoltaics and other solar power methods.

"The hydrogen economy is a proposed system of delivering energy using hydrogen. The term hydrogen economy was coined by John Bockris during a talk he gave in 1970 at General Motors (GM) Technical Center.[1] Hydrogen advocates promote hydrogen as a potential fuel for motive power[2] (including cars and boats), the energy needs of buildings and portable electronics. Free hydrogen does not occur naturally in quantity, but can be generated by steam reformation of hydrocarbons, water electrolysis or by other methods. Hydrogen is thus an energy carrier (like a battery), not a primary energy source (like coal). The feasibility of a hydrogen economy depends on issues of electrolysis, energy sourcing, including fossil fuel use, climate change, and sustainable energy generation."

" Geothermal Electricity Production Most power plants need steam to generate electricity. The steam rotates a turbine that activates a generator, which produces electricity. Many power plants still use fossil fuels to boil water for steam. Geothermal power plants, however, use steam produced from reservoirs of hot water found a couple of miles or more below the Earth's surface. There are three types of geothermal power plants: dry steam, flash steam, and binary cycle. Dry steam power plants draw from underground resources of steam. The steam is piped directly from underground wells to the power plant, where it is directed into a turbine/generator unit. There are only two known underground resources of steam in the United States: The Geysers in northern California and Yellowstone National Park in Wyoming, where there's a well-known geyser called Old Faithful. Since Yellowstone is protected from development, the only dry steam plants in the country are at The Geysers. This geothermal power plant generates electricity for the Imperial Valley in California. Credit: Warren Gretz Flash steam power plants are the most common. They use geothermal reservoirs of water with temperatures greater than 360°F (182°C). This very hot water flows up through wells in the ground under its own pressure. As it flows upward, the pressure decreases and some of the hot water boils into steam. The steam is then separated from the water and used to power a turbine/generator. Any leftover water and condensed steam are injected back into the reservoir, making this a sustainable resource. Binary cycle power plants operate on water at lower temperatures of about 225°-360°F (107°-182°C). These plants use the heat from the hot water to boil a working fluid, usually an organic compound with a low boiling point. The working fluid is vaporized in a heat exchanger and used to turn a turbine. The water is then injected back into the ground to be reheated. The water and the working fluid are

solar energy

"Pollution free production of energy. Since geothermal energy does not require fossil fuels to be burned, production of electricity using this type of energy can be considered as pollution free. Sometimes, there is the tendency that this could release some harmful gases from beneath the earth that might actually be harmful. However, these gases could be contained."

" Where does Wind Energy come From? All renewable energy (except tidal and geothermal power), and even the energy in fossil fuels, ultimately comes from the sun. The sun radiates 174,423,000,000,000 kilowatt hours of energy to the earth per hour. In other words, the earth receives 1.74 x 10 17 watts of power . 1) About 1 to 2 per cent of the energy coming from the sun is converted into wind energy. That is about 50 to 100 times more than the energy converted into biomass by all plants on earth. 2)"

"Bio-fuel is produced directly from plant matter typically corn, sugar cane, sugar beets, or cellulose transforming it into alcohol. Fossil fuels are produced by either the decomposition of plant or animal matter over long periods of time under certain conditions such as high temperature and "

"Wind power will become cheaper than fossil fuel in the next few years (when the price of carbon is added to coal and oil), and in many places already is."