Modern renewable heating methods are all about making the most of the free energy sources in the world around us. The earth itself can be a good source of heat and many homes now make use of this fact by extracting the heat through a ground source heat pump which is used to power central heating or to heat water.
How it works
A ground source heat pump relies on the fact that the ground temperature below a depth of roughly 6m tends to be constant all year around. Setting up a ground source heat pump involves digging down into the ground to place loops of pipes containing fluid. The fluid circulates around the system, absorbing warmth from the ground in the deepest part of the loop. It then passes through a compressor which raises the temperature further and then transfers the resulting heat to water or air which will feed into the building’s central heating or hot water system.
There are various arrangements for pipes, depending on the amount of land space available, but they are most often laid in horizontal loops, which requires trenches to be dug as a part of the installation process. If only a small amount of ground space is available, the loops may be arranged vertically instead, which obviously results in the need to dig much deeper in order to install them.
Ground source heat pumps are not suitable for every building and are most efficient when built in as part of an entirely new home. However it is often possible to convert or replace existing systems to run on ground sourced heat. The advantages of harvesting heat from the ground are clear, as the heat is free, no fuel is required and the system needs very little maintenance, once installed.
You may also be eligible for payments under the UK government’s Renewable Heat Incentive (RHI) scheme, which pays grants to homes that use renewable sources of heat and power. Converting to a renewable source of heat also has obvious benefits for the environment as it cuts down on the use of power generated by fossil fuels and reduces CO2 emissions.
Typical installation costs for a ground source heat pump range between £13,000-£20,000. Costs per kW of peak heat output vary from up to £2,400 for a smaller system (5-10kw) to below £2,000 for a larger system (10-20kw). Horizontal systems based around loops placed in trenches will be cheaper than bore hole or vertical systems. Generally, the larger the size of the system installed, the lower the unit price per Kw will be.
Things to take into account when you are considering installing a heat pump include the amount of land space available. A horizontal loop system will cost less but require more land space to install. You should also assess the current heating system and insulation status of your home. The heat generated from ground sources tends to be lower temperatures than the average central heating system, so is impractical to use with a radiator system and better installed in conjunction with an underfloor heating system. Due to the lower temperatures, it is also imperative that your home is extremely well-insulated to prevent the loss of the heat generated.
If you are unsure whether a ground source heat pump is the best solution for your home, we at Franck Energy offer help and advice for those looking to switch to renewable energy solutions.
We are friendly and knowledgeable and will gladly take you through the various options available and help you to consider the factors that come into play in your unique home and situation.