Geothermal energy is an abundant and renewable source of energy that can be harnessed from the Earth's natural heat. It is a clean, sustainable, and cost-effective way to generate electricity and heat homes and businesses. Geothermal energy can be
From Wikipedia
Geothermal energy is thermal energy extracted from the Earth's crust. It combines energy from the formation of the planet and from radioactive decay. Geothermal energy has been exploited as a source of heat and/or electric power for millennia.