From our home on the earth's thin crust, it's hard to believe that 99.9% of the earth's volume is hot enough to boil water. Atomic decay inside of the earth heats its molten core to a temperature that is hotter than the surface of the sun! To harness this geothermal power, we need only drill through the crust and use that heat to boil water to drive turbine generators. This water can be reinjected into the earth in a closed loop.