It is believed that the first geothermal energy use in industry was during the late 18th century near Pisa, Italy. This history of geothermal shows energy been used to extract boric acid from the Larderello Fields through the use of steam

The heat from the earth's own molten core can be converted into electricity. This core consists primarily of extremely high temperature liquid rock known as magma. This "geothermal" heat circulates within the rock or is transferred to underground reservoirs of water, which also circulate under the earth's crust. Because of the near limitless ability of the earth to produce magma, and the continuous transfer of heat between subsurface rock and water, geothermal energy is considered a renewable resource.

Geothermal energy is heat that is generated within the Earth.