geothermal def.
Geothermal energy produces 90% of the world’s energy. Geo means Earth and thermal means heat. Geothermal power plants use hydrothermal recourses and have two common ingredients. Water is hydro and heat is thermal. Geothermal plants require high temperature between 300 and 700F. Hydrothermal resources may come from steam or hot water well. Most geothermal of hot water were found in the western states, like Alaska and Hawaii. Hot water can be used to heat buildings, grow plants in green houses, drying crops, heating water and fish farms, and several industrial processes such as pasteurizing milk.
http://ecochamber.com/2009/01/geothermal-energy-description/ -----------------