What is Geothermal Webpage GEO-HEAT CENTER What is Geothermal?
Geothermal Energy Geothermal Energy is heat (thermal) derived from the earth (geo). It is the thermal energy contained in the rock and fluid (that fills the fractures and pores within the rock) in the earth’s crust. Calculations show that the earth, originating from a completely molten state, would have cooled and become completely solid many thousands of years ago without an energy input in addition to that of the sun. It is believed that the ultimate source of geothermal energy is radioactive decay occurring deep within the earth (Burkland, 1973). In most areas, this heat reaches the surface in a very diffuse state. However, due to a variety of geological processes, some areas, including substantial portions of many western states, are underlain by relatively shallow geothermal resources. These resources can be classified as low temperature (less than 90°C or 194°F), moderate temperature (90°C – 150°C or 194 – 302°F), and high temperature (greater than 150°C or 302°F). The uses to wh
