Ground Source heat pumps (gshp) extract heat stored in the ground. At depths of 2m and more, the ground temperature does not deviate very much from the average summer/winter surface temperatures (around 9 -12C in the UK depending on location). The most practical way of extracting this energy is to bury a large amount of pipe in the ground. This is usually laid in horizontal trenches at 1.5 – 2m depth, but vertical bore-holes are an alternative method giving similar results.