Ground Source Heat Pumps (GSHPs)
Ground Source Heat Pumps (GSHPs) use natural heat from the ground to heat your home via pipes buried in the garden.
This heat is then used to heat radiators, underfloor or warm air heating systems and hot water.
During the winter months heat is taken directly from the ground whilst in summer it can be sourced from a heat sink. As the temperature under the surface of the ground is moderate and remains at a fairly constant temperature, a GSHP can be used all year round.
As GSHPs works using a combination of geothermal energy (from the earth’s core) and solar energy (from the sun) they are sometimes referred to as geothermal heat pumps, earth energy heat pumps, geo-exchange pumps and water source heat pumps.
How do they work?
In the UK there are marked seasonal differences in our weather, sometimes reaching high temperatures in the summer months and falling below zero during the winter. In spite of these fluctuations, just a few metres down under the surface, the ground temperature remains fairly constant.
A Ground Source Heat Pump (GSHP) absorbs this low temperature heat into a fluid in an underground loop of pipe (ground loop). The fluid travels through a compressor which raises the temperature drawn from the ground so that it can then be used to heat domestic heating and hot water systems. The cooled ground loop fluid is passed back into the ground where it continually absorbs further energy from the ground for as long as heating is required.
There are three main components to a GSHP; a ground heat exchanger that collects heat from the ground, a heat pump that increases the temperature of the heat collected and a heat distribution system.
A ground heat exchanger consists of an invisible ground loop buried in the garden. A ground loop is usually laid flat or coiled in trenches but if space is of a premium, it is sometimes possible to install a vertical loop.
There are two types of ground loop; an indirect circulation system and a direct expansion system. An indirect circulation system is the most common and this comprises a sealed loop made from high density polyethylene pipe containing a mixture of water and antifreeze. The liquid is pumped around the loop and the energy collected is transferred indirectly to the heat pump refrigerant via the heat exchanger. With a direct expansion system the refrigerant is circulated directly through a copper ground source heat exchanger.
Direct expansion systems are generally more efficient than indirect expansion systems but require more refrigerant and carry the risk of potential leaks.
A heat pump is powered by a small amount of electricity. It increases the temperature of the heat drawn from the ground to a sufficient level to provide heating and hot water in your home. A typical heat pump will operate at a ground temperature of -5 degrees Celsius to 12 degrees Celsius.
Planning permission is not generally required to install a GSHP in England, Scotland Wales but it is as well to check with your local planning office. In Northern Ireland planning permission may be needed and you should consult your local authority for current requirements,
The RHI ( Renewable Heat Incentive) tariff levels have been set at:
- Solar thermal: 19.2p/kWh (minimum)
- Biomass boilers: 12.2p/kWh
- Ground source heat pumps: 18.8
- Air source heat pumps: 7.3p/kWh
Please try our renewable heat incentive calculator, enter your current heating arrangements and costs then chose the preferred Renewable heating system. We will then work out the costs and returns from this scheme.
You can book a Free Energy Assessment survey today – we’ll discuss your options and help you to decide what’s best for your needs.
Advantages of Ground Source Heat Pumps (GSHPs)
- GSHPs are more carbon friendly than systems powered by fossil fuels.
- A GSHP is a long lasting and very reliable form of home heating.
- Low maintenance.
- There are no visible external components.
- GSHPs do not require a boiler.
- No flue or ventilation is required.
- Installing a GSHP will reduce your fuel bill by 70%.
- A GSHP will generate an income via the government’s Renewable Heat Incentive (RHI) for 7 years @ £2,500 – £7,000 per year
- A one off grant of £2,300 RHPP to the initial cost
- Can provide hot water as well as heating.
Costs and potential savings
You can expect to pay between £9,000 and £17,000 to install a typical Ground Source Heat Pump (GSHP) system. Running costs thereafter will depend on several factors such as the size of your home and if it is well insulated. Pay back is generally 3-5 years with cost savings and RHPP grants @ RHI Incentives.
As Ground Source Heat Pumps (GSHPs) run on electricity, you will still have to pay some bills but you will save money on the fuel you are replacing and maintenance costs are minimal.
Once up and running, it is estimated* that installing a typical GSHP for residential heating will provide savings, depending on the type of system you are replacing: the best savings are on Electricity Saving 70-90%, Oil Heating 70-80% Saving.
Renewable Heat Premium Payment
The Renewable Heat Premium Payment is the forerunner to the Renewable Heat Incentive (RHI) for householders. It is a government backed scheme to help domestic users pay for renewable energy technologies in the home. The payment amount varies according to which technology you are applying for. The voucher for GSHPs is worth £2,300 from May 2013.
Anyone living in England, Scotland or Wales who uses an appropriate renewable energy system to heat their home can apply for the Renewable Heat Premium Payment.
Mr Renewables Services for GSHP
Design and Installation of GSHP for both domestic and commercial applications, Small, Medium or large
On going support after installation with servicing packages
Specification for underfloor heating, radiators and hot water needs
Bore Holes, Ground loops engineering service for a complete installation solution