The Basics: Many technologies have been developed to take advantage of geothermal energy—the heat from the earth. This heat can be drawn from several sources: hot water or steam reservoirs deep in the earth that are accessed by drilling; geothermal reservoirs located near the earth’s surface, mostly located in western states, Alaska, and Hawaii; and the shallow ground near the Earth’s surface that maintains a relatively constant temperature of 50°-60° F.
This variety of geothermal resources allows them to be used on both large and small scales. A utility can use the hot water and steam from reservoirs to drive generators and produce electricity for its customers. Other applications apply the heat produced from geothermal directly to various uses in buildings, roads, agriculture, and industrial plants. Still others use the heat directly from the ground to provide heating and cooling in homes and other buildings. (National Renewable Energy Lab, 2010)
How it Works: Our own backyard has the potential to be an energy source for heating and cooling comfort. Outdoor air temperatures fluctuate throughout the year with the changing seasons. In contrast, ground temperatures about four to six feet below the earth’s surface remain relatively moderate and constant all year. That’s because the earth absorbs 47% of all the heat energy that reaches its surface from the sun. A geothermal system circulates a water-based solution through a buried loop system to take advantage of these constant temperatures. Geoexchange systems have the ability to heat and cool homes, buildings, schools, and municipalities and provide some or all of your home’s hot water as well. Furthermore, geoexchange systems provide domestic hot water for pools and hot tubs with other benefits including snow melt, refrigeration, and hot water for radiant floor heating.??A geothermal heating and cooling system is an excellent alternative to the escalating cost in natural gas prices; particularly since residential consumers have absorbed a 27% increase in natural gas costs. With no end in site to the elevated natural gas prices, installing a geoexchange system will save you 30%-70% on your utility costs annually. (Rocky Mountain Geothermal Inc, 2010)