Geothermal power is a form of renewable energy generated from heat that naturally occurs within the Earth. Radioactive materials, such as uranium and potassium, decay and produce heat deep underground, which is reachable through weak spots or boundaries in tectonic plates.
The extreme heat caused by magma within the Earth's crust is a major form of geothermal power. It is harnessed by large power plants and used to provide electricity to communities. These plants use steam to power a turbine, which creates electricity. Since mild geothermal energy can be found as little as 10 feet underground, it is also used directly to heat homes, greenhouses and other buildings by way of a ground-source pump.