Geothermal Energy for Homes

Geothermal Systems are becoming increasingly popular with new home builders and with those who wish to make their existing homes less expensive to operate. These systems can be used to make heating much more efficient as well as to provide air conditioning in the summer. In addition, domestic hot water (and even a hot tub, if you have one) can be heated by the system.

Normally, energy is extracted from water that has circulated in pipes that are buried underground. The depth of the pipes is a minimum of five feet, (below the frost line), where the temperature remains relatively constant all year round at 13ºC (55ºF).

The water can be circulated in pipes that are placed horizontally in the earth, or run vertically into the ground when the space around a home is limited. A third option is to pass a pipe loop into a fairly deep pond, or a flowing aquifer, and extract energy from the water. In the winter heat is extracted from the ground and in the summer excess heat from the home is transferred to the ground.

A heat pump provides the heating and cooling required in a home. The heat pump operates in a manner somewhat similar to a fridge. Air circulating through the inside of a fridge would be cold. Air passing over the heat exchange coils at the back of the fridge would heat up. This is essentially how a heat pump can either heat or cool a home. Extracting energy from geothermally heated water simply means that the heat pump needs less overall electricity to operate. Geothermal systems typically reduce heating costs to between a quarter and a third of what they would cost without the system and cooling costs are cut in half.

It costs more to install a geothermal system than a conventional heating and cooling system but it costs far less to operate, and the saving of energy helps to protect the environment. Ground loop systems are maintenance free and the rest of the in-home system requires minimal attention. If a family anticipates living in a house for a number of years geothermal is an excellent addition which also enhances the resale value of a house.

Several local companies, listed in the Yellow Pages, can install geothermal systems. Another, less expensive option, only recommended if you are a very competent DIY person, is to purchase a geothermal kit; see for details.