Geothermal Energy: Meeting Our Energy Needs

Heat from the Earth or geothermal energy can be and already is accessed by drilling water or steam wells in a process similar to drilling for oil. Geothermal energy is an enormous, underused heat and power resource that is clean or emits little or no greenhouse gases. It also is very reliable and is homegrown making us less dependent on foreign oil. Geothermal resources range from shallow ground to hot water and rock several miles below the Earth’s surface. Deep wells can be drilled to tap steam and very hot water that can be brought to the surface for use in a variety of applications. In the U.S., most geothermal reservoirs are located in the western states, Alaska and Hawaii.

The U.S. generates more geothermal electricity than any other country but the amount of electricity it produces is less than one-half of one percent of the electricity produced in the U.S. Only four states have geothermal power plants. California has 33 geothermal power plants that produce almost 90 percent of the nation’s geothermal electricity. Nevada has 14 geothermal power plants and Hawaii and Utah each have one geothermal plant.

Almost everywhere, the upper 10 feet of Earth’s surface maintains a nearly constant temperature between 50 and 60 degrees Fahrenheit. A geothermal heat pump system consists of pipes buried in the shallow ground near a building along with a heat exchanger and ductwork into the building. In winter, heat from the relatively warmer ground goes through the heat exchanger and ductwork into the building. In the summer, hot air from the building is pulled through the heat exchanger into the relatively cooler ground. Also, technology is being developed to drill into hot dry rock being heated by molten magma. Cold water is injected down one well and circulated through the hot fractured rock and then the heated water is drawn off from another well. Geothermal energy does not deplete like oil and natural gas fields, so geothermal energy is considered a renewable form of energy and therefore eligible for significant investment tax breaks.