Summary:
- Geothermal energy stems from Earth's internal heat.
- Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface.
- In the United States, California leads all states in producing geothermal energy.
- The largest plant is in the Geysers Geothermal Resource Area.
- Geothermal energy is clean and safe.
- It is renewable.
- It does not release greenhouse gases.
- But it is not economical everywhere.
- Many parts of the world do not have underground sources of heat that are close to the surface for building geothermal power plants.