Renewable Geothermal Energy
Solar heat which has been stored in the earth’s crust provides the inexhaustible source of supply energy for a geothermal heat pump. This energy is replenished each year by the sun during the normal cycle of our seasons. There is enough solar energy stored beneath each building to more than supply the cooling and heating requirements. All we need to do is extract that energy and the geothermal heat pump has been designed to do just that!
Studies by the US Department of Energy and Natural Resources Canada ranked new generation geothermal heat pumps above all other heating and cooling systems in their ability to conserve energy and reduce CO2 emissions.
When compared to an electrically heated home, geothermal heat pumps consume less than 1/3 the amount of electrical energy to heat the structure. Consequently the electric utility company generates only 1/3 the emissions it normally would.
How Energy Efficient Is GHP (Ground-Source Heat Pump) Technology
Geothermal Heat Pumps (Ground-Source Heat Pumps) are electrically powered home heating and cooling heat pumps which transfer heat to and from the earth via a refrigeration process. Geothermal Heat Pumps have been in operation for over 50 years and operate on the same principle as your household refrigerator or air conditioner.
During winter operation heat energy is absorbed from the ground via underground tubing or by pumping well water to the heat pump. The heat pump mechanism concentrates this energy and delivers it to the home in the form of warm air or hot water.
During summer operation the process is reversed. Warm air is collected from the home and rejected to the cooler earth. On most models, domestic hot water is produced any time the heat pump operates.
Geothermal Heat pumps are available for both forced air and radiant floor heating systems in a variety of output capacities which can accommodate any building design.
Efficiencies of Heat Pumps
The efficiency of a heat pump depends upon the temperature at which it finds its heat (source temperature) and the temperature at which it discharges this heat (sink temperature). The greater the difference between the source temperature and sink temperature, the more work is done by the compressor in the heat pump; and consequently, the more cost.
In other words, as the source temperature declines, so will the efficiency of the heat pump. The prospective buyer will naturally choose the type of heat pump (air source vs. ground source) which gets its heat from the source that remains at the highest temperature for most of the year.
During the heating season in our part of Canada, our mean ground water temperature will remain 47°F (8°C) where the mean winter air temperature is approx. 12°F (-10.4°C). It is for this reason that seasonal efficiencies of a ground source heat pump are much higher than an air source.
Where does the energy come from?
There are two common sources of energy from which a heat pump could transfer
The AIR around us.
The EARTH beneath us.