Energy term of the day: geothermal energy

Geothermal energy is the term used to describe energy that is stored in the Earth as a result of the radioactive decay of minerals and the conduction of heat from the core of the planet.

Applications and use of geothermal energy include heat pumps on a domestic scale, but geothermal power stations across the world create some 11,400 megawatts of energy per year.

Wikipedia page.