Answer: Geothermal energy
Geothermal energy is the energy that is stored inside the deep layers of the earth. The energy is produced in the form off heat energy, harnessed by the extremely high temperature and pressure on the rocks and water. The example of geothermal energy is hot spring. The hot water emerge out from the earth crust. Geothermal energy is utilized for the generation of electricity and in thermal power plants as energy source.