Green Building

Geothermal

Geothermal energy is a renewable and reliable source of heat. Because 46 percent of solar energy is absorbed by the earth, at a depth of approximately six feet, the soil maintains a consistent average temperature of between 42-77 degrees Fahrenheit year round. Geothermal heat pumps use this natural energy to heat and cool water circulated through an underground loop. The system directs conditioned air to zones within a building. This natural energy source often eliminates the need for traditional heating and cooling.

Unlike conventional heat pumps, with geothermal heat pumps, it is much easier for the system to capture heat from soil of a moderate temperature than from the frigid air outside in winter. Conversely, in summer, the relatively cool ground absorbs waste heat more readily than warm outdoor air.

In some instances, subsurface water is so warm it can even provide direct heating and be used to run steam turbines that in turn create electricity.

According to the Environmental Protection Agency, geothermal energy is the most energy-efficient system of air handling and can lower energy costs by 25 to 40 percent, with fewer emissions, lower maintenance and no danger of underground contaminants. There is also a reduced use of refrigerants.