The Department of Energy funded a program in 1991 to update the inventory of geothermal resources for direct-heat applications and to promote geothermal heat pumps in the U.S. Geothermal energy comes from heat deep in the earth, creating hot water and steam. Using geothermal energy has environmental benefits and is more reliable than traditional energy sources. It helps with electricity generation, heating, and cooling buildings, reducing the need for electricity and natural gas.