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8: One Megawatt of Wind Energy = 2,600 Fewer Tons of Carbon Dioxide So, with all the noise about clean energy, what kind of improvement are we really talking about with wind? Consider that every year 1MW of wind energy can offset approximately 2,600 tons of carbon dioxide (CO2) [source: NREL], and the interest comes into focus. The simple math is less fossil fuel consumption equals less CO2. And measuring carbon reduction has become a key benchmark for monitoring the progress of alternative energy adoption.

Wind Energy The answer is blowin’ in the wind How is man going to keep up with increasing energy demand while the amount of available fossil fuel diminishes? The answer could be wind power, the capturing of the energy contained in gusts of wind. What is wind Energy?

Man has been using wind energy for thousands of years. Windmills, sails and even kites are all devices designed to harness the awesome power produced when the wind blows. Even modern aircraft benefit from wind power. Pilots flying westward usually expend much effort trying to make sure they place themselves in the jet stream, the hundred mile per hour wind caused by the earth spinning. Now engineers are able to convert such power into electricity, pump it into grids and provide energy for homes.

What is U.S. electricity generation by energy source? In 2012, the United States generated about 4,054 billion kilowatthours of electricity.  About 68% of the electricity generated was from fossil fuel (coal, natural gas, and petroleum), with 37% attributed from coal. Energy sources and percent share of  total electricity generation in 2012 were:  Coal 37% Natural Gas 30% Nuclear 19% Hydropower 7% Other Renewable 5% Biomass 1.42% Geothermal 0.41% Solar 0.11% Wind 3.46% Petroleum 1% Other Gases < 1%

Somewhat surprisingly, the hot air that carries the heat from the earth at geothermal sites also contains carbon dioxide, CO2, the Greenhouse Gas that sends anti-technologists into a frenzy.  The suite of 20 geothermal sites from which Southern California Electric is obligated to buy electricity produces 730 tonnes of CO2 for every gigawatt-hour (GWh) of electricity produced.  Across the spectrum of all natural-gas power plants in the US, the average CO2 production is 519 tonnes per GWh.  That is, the geothermal power plants, which burn no fossil fuels whatsoever, produce 41% more CO2 than the run-of-the-mill natural gas power plant for the same amount of electrical energy produced.

Lost in the mix are the biofuels, fuels made from biological ingredients instead of fossil fuels. These starting ingredients can range from corn to soybeans to animal fat, depending on the type of fuel being made and the production method.

Photovoltaic cells are made of at least two layers of semiconducting material. The first layer has a positive charge; the next layer has a negative charge. When sunlight strikes the cell, the semiconducting material absorbs photons from the light. This process frees electrons from the negative layer, which move to the positive layer. This flow of electrons constitutes an electric current, which can be captured in a circuit connecting the two layers. The electricity generated by a photovoltaic cell can be used directly, stored in batteries or sold back to a utility company.

The amount with in the earth’s surface contains 50,000 times more energy than all the oil and natural gas resources in the world.

To get that heat, water is pumped down an “injection well”. Then it filters through the cracks in the rocks where they are at a high temperature. The water then returns via the “recovery well” under pressure in the form of steam. That steam is captured and is used to drive electric generators.