1. Chelsey Colvin Geothermal Energy What is Geothermal Energy? Geothermal energy is a renewable source of energy that barely does any damage to the environment. It comes from the heat within the earth that is constantly created because of the slow decay of radioactive particles that occurs in rocks every day. The hottest geothermal regions can be found near plate boundaries where earthquakes and volcanoes centralize. Majority of the world’s geothermal activity happens in the area that is ear the Pacific Ocean that is known as the Ring of Fire. Geothermal energy is use through out the world to heat buildings and to produce electricity. How is Geothermal Energy used? There are many different strategies that geologists use while searching for geothermal reservoirs. They study aerial photographs and geological maps, analyze the chemistry of local water sources and the concentration of metals in the soil, and they measure variations in gravity and magnetic fields. Though all these methods help lead them to geothermal reservoirs the only way to be sure they have found one is by drilling an exploratory well. Once they have found the reservoir then they drill a production well. Next, turbines that are turned by 250-700 degree Fahrenheit hot water and steam generate electricity. Cost: Geothermal systems are more expensive to install than conventional heating and cooling systems but they are economically friendly in the sense that they save you money in the long run. They can reduce heating costs by 50-70 percent and cooling costs by 20-40 percent. Geothermal systems need little maintenance and can last twice as long as conventional systems. On average a homeowner can save about $20,000 over the life of a system. Geothermal energy is economically efficient because no fuel is used to produce the energy. Benefits: One major advantage of using geothermal energy is it is renewable energy and it does little damage to the environment and does not polute the aire. Also, the geothermal power plants’ emission levels are very low because they do not burn fuel to generate electricity. Next, they are convenient because the government allows development on federal lands because the power plants do not cause harm to the environment. Since geothermal energy does not need fuel to produce electricity it avoids importing from other countries and therefore benefits local communities. Disadvantages: Although geothermal energy is advantageous it also has some disadvantages. Geothermal steam and hot water contain traces of hydrogen sulfide and other gases and chemicals that could be harmful in large quantities. Since geothermal steam and hot water only contain small traces of these materials it is not very damaging to the environment. One last disadvantage is that very rarely a working plant may randomly stop producing steam and this stall in productivity can last up to ten years. Possibilities: It is predicted that improvements in technology will make it easier to use geothermal resource, bring the cost down and increase the number of geothermal reserves. Different Types Of Geothermal Power Plants -Flashed Steam Plants are the most commonly used of the power plants. They function when the hot water from the production wells “flash” or boil violently and create steam that is used to spin the turbine generator. -Dry Steam Plants are located in the geothermal reservoirs that produce mostly steam and very little water. The steam that comes from the reservoir goes directly thought a rock catcher and into the turbine generator. -Binary Power Plants produce electricity by transferring the heat from geothermal hot water into other liquids. The fluid that the heat is transformed into is then boiled and its vapor is used to spin the turbine generator. -Hybrid Power Plants are a combination of flash and binary power plants. In Hybrid plants both heat and steam are utilized. -GeoExchange Systems utilize the Earth’s constant temperature that lies about twenty feet below the surface to heat and cool buildings. Heat pumps remove heat from a heat exchanger and pump it into an indoor air delivery system to heat the building. To cool the building the reverse action is taken and heat is taken out of the indoor air that can be saved and used to heat water. This is a map showing where the Ring of Fire, the worlds most geothermal activity happens here. Scale: The use if geothermal energy is growing larger because of its vast advantages and slim disadvantages. Geothermal heat exchange systems are an efficient and economical alternative to conventional heating and cooling systems. In the United States more than 300,000 homes and buildings use geothermal heat exchange. Geothermal energy compromises four percent of the total U.S. domestic energy reserves. “In our world today there are 250 geothermal power plants in 21 countries, supplying 8,200 megawatts of electricity to 15 million people. Direct uses of geothermal reservoirs amount to over 11,00 megawatts of thermal energy in 35 counties. And an additional 40 countries use hot springs and spas but have not yet commercially developed their geothermal reservoirs.” Taken from (http://www.learnaboutenergy.org/focus/part10.htm) This is a diagram of what a Flash Steam Power Plant may look like. This is a diagram of what a Binary Cycle Power Plant may look like. This is a diagram of what a Dry Steam Power Plant may look like. A geyser is one of the most commonly used resources to collect geothermal energy. This is a picture of a geothermal power plant located in Iceland. Bibliography: "Disadvantages of Geothermal Energy." Clean-energy-ideas.com. Web. 2010.. This website taught me about the disadvantages of geothermal energy. "Geothermal Energy Facts." Our-energy.com. Web. 25 Mar. 2010.. This website gave me general information about geothermal energy. It also had a few interesting facts. "Geothermal Energy." Renewableenergyworld.com. Web. 25 Mar. 2010.. I used this source to find out about the uses of geothermal energy. Also, this explained a lot about heat pumps. Http://standeyo.com/Reports/041222.EQ.warning/West.Coast/ring.of.fire. gif. Web. 30 Mar. 2010. The picture of the map of the ring of fire came from this site. "What Is Geothermal Energy? Can It Be Utilized in Your Home?" Alternative-energy-resources.net. Web. 29 Mar. 2010.. I took the diagrams of the different kinds of power plants from this site. "What Is Geothermal Energy?" Learnaboutenergy.org. Web. 26 Mar. 2010.. I used this website for most of my information. It taught me about all the different kinds of power plants.