If you have ever been in a cave, you probably remember how cool it was. All caves are about the same temperature: around 55 degrees Fahrenheit (13 degrees Centigrade). Dig down about 6-8 feet (2 to 2.5 meters) in your back yard and you have a similar effect. The ground is a relatively constant temperature of around 55 degrees F.
Therein lies the basis for geothermal technology that offers an essentially limitless source of non-fossil fuel based energy. Geothermal technology, also referred to as geo-exchange, takes advantage of the constant temperature zone underground and uses it as an enormous heat sink to absorb heat in the warmer months. Then, in winter when heating is desired, the same constant temperature becomes a heat source to offset the need for other energy sources to provide heating. All that is needed is a system of pipes buried in your back yard that can carry out efficient heat exchange, providing cooler air for you home in the summer and warmer air in the winter.
The idea is simple, but the technology is not simplistic. Systems should be well-engineered to maximize heat transfer and create maximum efficiency. But when done properly, the payback, especially if included in a new construction, is faster than that offered by solar or wind power.
Geothermal technology is not a new idea, but it has been ignored compared to more popular and popularized technologies such as solar photovoltaic panels, wind power, and biofuels. But the benefits of geothermal technology are compelling.
First of all, geothermal heating and cooling emits no greenhouse gases at all. It could also help countries become more energy independent and less reliant on sources of imported oil and gas.
A second benefit is that geothermal technology is not dependent on the vagaries of the weather. The geo-exchange process functions 24/7. The results are the same whether it is sunny or not, and regardless of whether the wind is blowing.
Then there are the economic advantages. A geo-exchange heating and cooling system works with existing ducts and reduces the need for heating and cooling from your already installed systems. As an add-on, a new geothermal exchange system can provide a payback of around 10 to 15 years without taking into account any government incentives. Depending on where you live and the incentives available, the payback in your specific case can be much shorter, as little as 3 to 6 years. If you are building a new home and can finance the cost of the geothermal installation as a part of the overall cost of the home, the reductions in heating and cooling costs will immediately provide positive cash flow at current home financing rates.
Geothermal technology should receive more attention as an energy source that causes no emissions of greenhouse gases and is almost limitless in its ability to provide cost effective energy to homes around the world.