Geothermal energy uses heat from within the Earth. It works by circulating water through underground loops of pipes to transfer heat. There are three main types of geothermal power plants: dry steam plants, flash steam plants, and binary cycle plants. Dry steam plants use steam directly from reservoirs. Flash steam plants depressurize hot water to produce steam. Binary cycle plants use hot water to boil a secondary fluid like isobutane that powers a turbine. Geothermal systems can use vertical loops, horizontal loops, pond loops, or open loops depending on available land and water resources.

1. Geothermal Energy

2. What is it? Two Greek words in it geo means earth and thermal means heat Basically, it is using water heated within the earth and using it for energy.

3. How it works These are the steps to making geothermal energy: Heat pumps in the ground move water continuously through a closed loop of a plastic pipe The heat pump then moves the heat from an area of low temperature to an area of high temperature This concept is similar to an air conditioner, (cold air comes in, warm air goes out)

4. Geothermal Power plants Designs There are three designs of geothermal power plants: Dry Steam: steam is goes into a turbine and then a condenser where it condenses to water Flash Steam: in order for the water to turn to steam, the water is depressurized, then it is used to power a generator Dry Steam Flash Steam

5. Geothermal Power plants Designs (continued) Binary System: the hot water is passed through a heat exchanger where the heat from the water is used to heat another liquid such as isobutane. Then the isobutane is heated a temperature where it can be easily transformed into steam. Binary System

6. Types of Loops Vertical Loop: This example is used when there is not a lot of land available. A drill then drills a 150-200 foot hole. A pipe is then inserted and the hole is then filled with a sealer. Horizontal Loop: This loop is used when there is a lot of land. Excavation material is used to dig 6-8 feet deep trenches that are 100 to 300 feet long

7. Types of Loops (Continued) Pond Loop: This is most common when there is a ½ acre wide and 8-10 foot deep body of water nearby. The pipe coils are most commonly 300 to 500 feet in length and are placed at the bottom of the water. Open Loop: This like the pond is used when there is a body of water around but in the open loop, there must be enough water to provide 4 to 8 gallons of water a minute. There must also be a discharge drain

8. Sources Works Cited Binary cycle. N.d.Union of Concerned Scientists. Union of Concerned Scientists, n.d. Web. 20 May 2011. <http://www.ucsusa.org/​clean_energy/​technology_and_impacts/​ energy_technologies/​how-geothermal-energy-works.html>. Dry Steam. N.d.Union of Concerned Scientists. Union of Concerned Scientists, n.d. Web. 20 May 2011. <http://www.ucsusa.org/​clean_energy/​technology_and_impacts/​ energy_technologies/​how-geothermal-energy-works.html>. Flash Steam. N.d.Union of Concerned Scientists. Union of Concerned Scientists, n.d. Web. 20 May 2011. <http://www.ucsusa.org/​clean_energy/​technology_and_impacts/​ energy_technologies/​how-geothermal-energy-works.html>. Geothermal Energy. N.d.BBC. British Broadcasting Company, n.d. Web. 17 May 2011. <http://news.bbc.co.uk/​2/​hi/​uk_news/​england/​cornwall/​ 3937771.stm>. Geothermal Energy. N.d.DebatePedia. N.p., n.d. Web. 17 May 2011. <http://debatepedia.idebate.org/​en/​index.php/​Debate:_Geothermal_energy>. Geothermal Energy. N.d.Going Eco Green. GoingEcoGreen, n.d. Web. 17 May 2011. <http://www.goingecogreen.com/​go-green-videos/​geothermal-energy/>. Renew Mechanical Inc. “Geothermal Energy.” Renew Mechanical Inc.N.p., 2010. Web. 24 May 2011. <http://www.renewmechanical.com/​geo_energy.htm>. Union of Concerned Scientists. “How Geothermal Energy Works .” Union of Concerned Scientists . Union of Concerned Scientists, 16 Dec. 2009. Web. 20 May 2011. <http://www.ucsusa.org/​clean_energy/​technology_and_impacts/​ energy_technologies/​how-geothermal-energy-works.html>. U.S. Energy Information Administration. “Renewable Geothermal.” Energy Kids. U.S. Energy Information Administration, n.d. Web. 17 May 2011. <http://www.eia.doe.gov/​kids/​ energy.cfm?page=geothermal_home-basics>.