Geothermal energy is energy that comes from the heat inside the Earth. The Earth's core is very hot and is always giving off heat. Geothermal energy harnesses this heat to create electricity. It works kind of like a fire. Just like you can turn a fire on a stove into energy, geothermal energy turns the heat inside the Earth into energy. It does this by taking the hot water or steam from deep underground and using it to spin a turbine. The turbine then creates electricity.