Ground source heat pumps draw as much as 75% of their energy from freely available, inexhaustible solar energy stored in the ground.
The earth stores an enormous amount of solar energy from both solar radiation and rainfall and more than 1m below the surface, you'll find a stable source of heat year-round.
To extract this heat energy, ground collectors consisting of flexible polyethylene pipes are buried in the earth, either horizontally or vertically. A mixture of water and anti-freeze is then circulated through pipe loops, attracting the heat and transferring it to the heat pump.