Geothermal Energy National Geographic Society
Nov 20 2012 nbsp 0183 32 Geothermal energy is heat that is generated within the Earth Geo means earth and thermal means heat in Greek It is a renewable resource that can be harvested for human use About 2 900 kilometers 1 800 miles below the Earth s crust or surface is the hottest part of our planet the core A small portion of the core s heat comes from the friction and gravitational