Geothermal

In the United Kingdom, the earth – a few meters below our feet – keeps a constant temperature of about 11- 12°C throughout the year as the ground stores heat from the sun during the summer months. Additionally heat radiating from the earth’s core can be found at greater depths and can be tapped into where the mantle is shallowest.

The easiest way to tap into geothermal heat sources is by using ground source heat pumps, a process that is widely used across Scandinavia with great success.

A heat pump works in the same way as a refrigerator, but in reverse. The collection system consists of a single deep borehole outside the building. Alternatively, where space permits, a looped array of pipes buried about 1.2 metres below the surface can be used. A mixture of water and an environmentally friendly anti-freeze solution are used as a process medium, circulating through the closed loop, absorbing thermal energy from the earth and carrying it to the heat pump.

Heat pumps operate on the same principles as a domestic fridge: the cold is recycled and the heat retained and converted into high-grade heat to be released in the home through under floor heating, radiators and into the hot water tank.

Once a ground-source heat pump is installed, there are no external fans and no visible external equipment. The system is quiet in operation, very safe and requires little, if any, maintenance.

Projects within the Park already taking advantage of this renewable energy source include The Old Repeater Station at Grindon, Bellingham Town Hall, Elsdon Village Hall, The Hytte, Saughy Rigg Farm, and Stonehaugh Community Hall, amongst others.

This technology is generally suited to accommodation providers and public buildings due to the high installation costs, but the introduction of the Renewable Heat Incentive payments from April 2011 may see certain larger households investing in this technology.

The Authority needs to carry out a scoping exercise to ascertain the further potential for rolling this system across the Park. Ground source heat pumps tend to be reliable systems and offer an energy efficiency ratio of 1:5. One unit of energy running the heat pump realises five units of heat from the system.

Geothermal Fact Sheet from the Energy Saving Trust (PDF - 200KB)

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External Link

• Ground Source Heat Pumps at the Energy Saving Trust