What is Geothermal?

Geothermal energy is the heat of the earth. The temperature underground remains constant throughout the year come rain or shine.

A Geothermal Heating/Cooling system simply transfers heat to and from the earth to provide a more efficient, affordable and environmentally friendly method of both heating and cooling.

“... amongst the most environmentally friendly heating and cooling systems available today..”

Green Energy
Geothermal systems are amongst the most environmentally friendly heating and cooling systems available today. They produce zero localised emissions, so there is no air pollution or contribution to global warming. They use the earth’s free and renewable energy and they operate at a typical 400% overall efficiency – that means for every unit of energy they use, they produce 4 more. An average domestic geothermal installation would create the same environmental benefits as planting 750 trees or save the electricity company burning approximately 9 tons of coal. Geothermal energy is an unlimited resource - the earth absorbs 47% of the sun’s energy, which amounts to 500 times more energy than is required by mankind each year. A 1m2 area of ground typically absorbs 1100kW per annum.

Geothermal Heat Pumps
The technology behind ground Source Heat pumps is very simple. It uses the same technology as a refrigerator. During the heating cycle, low grade heat is transferred from the ground to a heat pump where the temperature is increased before being pumped to the heating distribution system. This can also be reversed to create cooling. Rather than making heat, they take existing heat from the distribution system and move it to a lower temperature source in the ground loop. The distribution system can be, amongst other methods, via under floor heating, radiators or forced air delivery for heating or chilled floors, chilled ceilings or forced air delivery for cooling.

Closed Loop Installations
A closed loop system is a continuous loop of buried pipe, which typically contains an environmentally friendly solution of water and anti-freeze. As the water is pumped through the pipe, the thermal energy from the earth transfers to the fluid in the pipe, changing the temperature by a few degrees. This temperature is then increased / decreased by passing it through a heat pump.

The loops can be laid vertically, horizontally or in ponds and lakes, although vertical is often the only option when there is limited space.

The pipes are made of high density PE100 polyethylene and will last for many many decades and probably beyond. They are joined using electro-fusion which protects against leakage or contamination.

Open Loop Installations

Open Loop systems involve pumping water from wells, boreholes, ponds, rivers or even the ocean. The water is passed through pipe work to the heat pumps directly or more commonly via a plate heat exchanger and then into the heat pump where heat is extracted or rejected. The source water is then disposed of in an environmentally friendly manner. There are several ways to dispose of the spent water, these can include pumping water into a river, stream, lake or alternatively a second borehole is drilled to return the water to the same ground aquifer from which it came. The local Environment Agency will usually be consulted on Open Loop systems.