GEOTHERMAL ENERGY

     Scientists believe that the core of our planet is a large mass of molten material. They call this material magma. It may have a temperature of 800^OF.

     In most places on earth, the magma is many miles below the ground. But at some locations, it comes close to the surface, and it creates hot spots. When ground water comes in contact with these hot spots, the water turns to steam. The geysers in Yellowstone National Park are well-known examples of this geothermal energy in action.

     Incidentally, the name geothermal comes from geo (earth) and therm (heat). Geothermal means heat from the earth.

     Where geothermal energy is available in the form of steam (at a suitable temperature and pressure), it is a practical source of energy. At the geysers geothermal field in Northern California, enough electricity is generated to serve a city nearly the size of San Francisco.

     The steam is used to spin turbines that drive electric generators. The process is not complicated, particularly if the steam is hot and dry. Moist steam, though, may carry minerals from the water. And these minerals can clog and corrode the generating equipment.

     The United States has 1.8 million acres of land where geothermal energy is known to exist in various forms. This leads to the belief that geothermal energy may eventually become an important source of electricity. Some estimates indicate that 30% of our electricity will come from geothermal energy by the 21st Century.