Geothermal Heating Systems
Geothermal heating systems use geothermal energy to heat a building or hot water. Geothermal energy is naturally occurring thermal (heat) energy stored in or beneath the Earth’s surface. Geothermal heating systems collect a portion of this energy and use it as a heat source. There are geothermal power plants, which take advantage of natural geographical features like hot springs. These plants make use of naturally-occurring steam or hot water to power turbines and generate electricity. Other geothermal plants dig deep wells into the earth, where the temperature is warmer naturally. There are also geothermal heating systems designed for use at home. These domestic geothermal heating systems combine heat wells or heat loops with ground source heat pumps to transfer heat from the ground to inside the home.
Geothermal Heating At Home
Of course, most homes do not sit on active geysers, nor is it possible for homeowners to dig deeply into the Earth to access where the temperatures are higher. To compensate, domestic geothermal heating systems will include a ground source heat pump (also known as a geo exchange, a geothermal heat pump or simply a heat pump). The systems work like this; a relatively shallow well or a ground loop is laid (essentially pipes dug in the soil) which circulate a heat transfer fluid. As this fluid is heated, a ground source heat pump extracts the heat and then pumps the cooled fluid back into the soil to collect more heat. This process is often compared to that of a refrigerator operating in reverse; the system simply moves heat from outside the home to inside.
The Rise of The Hybrid
As with all heating systems, the more efficient and cost effective a system is, the better. In recent years, this urge for greater efficiency has led to the creation of hybrid heating systems, where traditionally separate technologies have been combined and integrated for a large increase in efficiency. The SunPump is a perfect example of such a hybrid system. The SunPump takes the heat pump from a geothermal heating system and integrates it into a solar thermal heating system. In effect, the system is like a geothermal loop that runs through solar thermal panels instead of the soil. The fluid in the system circulates boils at -50°C (-58°F), meaning that lots of heat can be drawn straight from the air around the panels instead of having to run the system beneath the ground. The solar thermal panels heat the fluid at the same time, generating even more energy. Enough energy is collected this way to allow the system to act as a home’s primary heating source, heating the home and domestic hot water all year round (and at night) without requiring another heating system.