Geothermal power is an old technology that is newly gaining fame.
Most states have local installers that will install underground tubing for the heating needs for your home or business.
This solution relies on the constant temperature of the Earth and uses a simple heat pump to transfer that temperature to your site. Usually geothermal heating installations also provide cooling during warmer temperatures.
On a commercial scale, there are geothermal power plants that utilize the convection currents of the fluids in underground pipes to turn a turbine and create electricity. These commercial power plants are on the rise, especially in the western U.S., where ground temperatures are higher than in other parts of the country.