ABSTRACT
Utilization ......................................................................... 440 14.6 Conclusion.................................................................................................... 440 References.............................................................................................................. 441
The natural heat of the earth is called geothermal energy. Geothermal is a hybrid word, combining geo (earth) and thermal (of heat). The term geothermal energy denotes the total thermal energy contained beneath the relatively thin and comparatively cool outer surface of the earth. This represents about 260 billion cubic miles of rocks and metallic alloys at or near their melting temperatures. Geothermal resources range from shallow ground to hot rock and water several miles below the earth’s outer surface, and even farther down toward the earth’s core, in the region of extremely high temperatures of molten rock called magma.
