In the search for sustainable energy options in the 21st century, geothermal heating is quickly rising to the top of viable solutions. Geothermal systems use the residual heat in the Earth to regulate heating and cooling in buildings. Instead of using fossil fuels, generators are used to transfer the kinetic energy in the heat to generate BTU's that are then transferred to the heaters and air-conditioning. Businesses are installing geothermals at an increasing rate, both to save money and to be pollution-free.