Ground source heat pumps work with boreholes to extract geothermal heat energy stored in layers of rock, providing a very stable heat source.
Solar energy stored in surface soil dissipates through the many rock layers beneath our feet to form a very stable heat source. Depending on the make-up of the geology, this can provide an excellent heat source for ground source heat pumps.
Boreholes are the collectors used to extract heat energy from rock for ground source heat pumps. They are a very discreet and compact solution when space saving and minimal ground disruption is a priority.
Typically just one borehole is required per dwelling depending on the underlying ground conditions. Boreholes are the most expensive collector but become especially economically viable on large commercial projects, those with district heating schemes, and sites with heat loads above 100kW due to the costs involved of assembling the drilling rig and its speed when on site.Read more
"I will liken him to a wise man, he who built his house on rock."
As in the Parable of the Wise and Foolish Builder, a house built on rock is far more beneficial for a borehole than a house built on sand. Geology plays a significant role in the depth and efficiency of rock boreholes due to their conductivity and thermal mass.
Kensa can recommend companies that can assess your geology and specifications for a borehole.Read more
How do ground source heat pumps extract heat from rock?
A drilling contractor is employed to drill a borehole approximately 90m deep x 150mm wide, depending on ground conditions, located within approx 20m of the property. Straight pipe is inserted into the borehole, and connected via a trench to the ground source heat pump.
Typically one borehole is required per property, with multiple boreholes being used for larger installations with greater heat demands or heat network schemes.Read more