Geothermal drilling allows access to capturing the earth's natural heat, which is relatively stable. Using geothermal heat pumps, this system can be used for heating or cooling. Water or other liquids are put through continuous loops that are buried vertically or horizontally next to the building. For cooling during hot weather, the heat is picked up by the fluid and transferred into the earth. Geothermal heat pumps use little electricity and are environmentally friendly. They can save up to 70% energy as opposed to natural gas, electric, propane or oil. Heat pumps are efficient and low in maintenance, having fewer mechanical components. The geothermal unit itself has a 30 year lifespan compared to the 15 year life span of a typical furnace. The use of geothermal heating also eliminates six tonnes of CO2 emissions from a typical home.