Medium-depth boreholes, which are drilled 300m below ground, differ from standard ground source heat pump borehole depths of 100 – 230m. Here, we examine the ways in which deeper boreholes could bring about more ground source opportunities for projects with limited land area – just like Daisyfield tower blocks.
Is there unexploited potential in medium-depth boreholes?
Ground source heat pump technology is vastly underused within the UK, despite boasting the best system efficiencies versus any other heating technology. This is often the case for densely populated urban areas, where space for the ground array might be at a premium. When installing ground source heat pumps in these locations, borehole geometry is key; if boreholes are drilled to a standard depth of 100 – 230m, projects can be ruled as unfeasible as there is insufficient space to install the required number of boreholes.
Drilling to depths of 300 – 400m means more pipe can be installed in the ground for the same amount of ground-level surface area. This would allow the loops to absorb extra energy, sustaining a higher heat load for domestic properties or commercial premises in urban or high heat loss locations.