Geothermal energy
Much too hot!
Deep down beneath our feet lies molten rock at ferociously hot temperatures!
2,500 kilometers down, between the lower mantle and the outer core (between A and B), very hot liquid rock bubbles upwards from a liquid iron core. At some places in the mantle where rock is fractured, this heat rises upward or even comes to the surface as volcanoes or geysers. Elsewhere, especially in broken granite, this heat can be tapped by deep wells.
Geothermal drilling can mean drilling for three miles down into the ground to reach the very hot broken granite rock
The intense heat, once piped to the surface, is turned to steam to power the turbines that then feed into the electric grid. The cooled water is then pumped back down. The whole system works like an enormous radiator.
Some useful links