Ground Source Heat Pumps: Green Energy Made Affordable
Ground source heat pumps are an effective as well as environmentally friendly investment that can help you save up to 50% on heating bills, when compared to conventional heating systems. There are several different types of ground source heat pumps. Some of the many advantages of ground source heat pumps (GSHP) include:
- Save £790 to £1425/year on your heating bill price when replacing an electric system
- Indoor components last approximately 25 years
- Ground loops last 50 - 100 years
- Equal distribution of heat
With incentives available from the UK government, saving money on heat pumps has never been easier.
Since the Earth absorbs energy released from the sun, underground temperatures remain constant year round. In the UK, the temperature of the Earth a few metres below our feet is constant around 11 degrees Celsius.
The purpose of ground source heat pumps is to absorb heat from one place and transport and release it to another location, in this case your home.
If you are ready to start lowering your heating costs, fill out the form on this page, and our sales team will provide you with up to four different suppliers to help you find the best ground source heat pump.
Are Ground Source Heat Pumps Suitable for my Home?
There are two different types of loop systems for ground source heat pumps, the open loop system and the closed loop system.
The open loop system extracts groundwater which passes through a heat pump where heat is extracted.
The closed loop system draws the heat from the ground itself and uses a continuous loop of piping connected to the indoor heat pump. There are three types of closed loop systems:
Horizontal Ground Source Heat Pump
The system is laid in horizontal trenches that are approximately 1-2 metres deep. It is more common in rural areas where there is more land available.
To install the horizontal system, the area required depends on the heating and cooling loads of your home, the depth at which your loop is going to be buried, your soil and its moisture, the climate, and the efficiency of the heat pump. The average 150 m2 home needs an area of between 300 and 700 m2.
Vertical Ground Source Heat Pump
Vertical boreholes are a more expensive alternative when there is not enough area to lay the pipes horizontally. It is more often the appropriate choice for suburban homes where space is restricted.
A hole is dug at least 6m into the ground for insulation and the total piping will be 50-150 m deep depending on the composition of the ground and the heat requirement of your home.
Closed Loop System for Pond/Lake
Although less common than horizontal or vertical systems, a closed pond loop is also an option. It is uncommon because it requires proximity to a body of water, so an open loop system is usually preferable.
It may be advantageous when poor water quality prevents the use of an open loop.
Price of Ground Source Heat Pumps
What are ground source heat pump prices? Setup costs are higher than more traditional systems, but the difference is usually compensated by energy savings. The Energy Saving Trust (EST) estimates it can cost between £11,000 and £15,000 to install a ground source heat pumps in your home.
Ground source heat pumps cost approximately £655 a year to run and around £13,000 to install. The total installation price includes the heat pump, drilling, and installation. Approximately 45% of the price is allocated to the heat pump, 45% towards the drilling, and 10% towards the installation itself. It is important to note that prices vary depending on the size of the system and any additional work required.
Installation Costs of Vertical vs. Horizontal Systems
Costs vary whether you set up a vertical or a horizontal system. With total system installation costs of 600-1150 £/kW for horizontal and 850-1500 £/kW for vertical systems, assuming a standard 8kW heat pump system, the following installation costs can be calculated:
The cost of drilling and lining a borehole for a ground source heat pump is typically £60-£100 per metre depending on geology.
The following is a table based on figures from the Energy Saving Trust, outlining the carbon dioxide and energy bill savings when using a ground source heat pump in England, Scotland and Wales. The exisiting systems listed are all non-condensing systems, which are likely the systems users are looking to replace.
|Current System||Savings on Energy Bill (£/year)||Carbon Dioxide Savings (kgCO2/year)|
|Gas||£440 -£660||2100 - 3300 kg|
|Electric||£790 - £1425||6700 - 11700 kg|
|Oil||£130 - £220||3000 - 4700 kg|
|LPG||£960 - £1500||2800 - 4500 kg|
|Coal||£590 - £990||7600 - 12100 kg|
Advantages and Disadvantages of Ground Source Heat Pumps
Contrary to popular belief, you don’t need several acres of land to install a heat pump. Even a modest garden can be used to benefit from the Earth’s heat.
Ground Source Advantages
- Ground source heat pumps are among the most energy efficient technologies for providing water heating
- Ground source systems are automated and have low maintenance and low running costs
- They make less noise than gas boilers and air source heat pumps
- Low environmental impact as they reduce carbon emissions and there is no carbon emissions if a renewable source of electricity is used to power them
- Longer lifespan of indoor components than an air source pump - up to 25 years for ground source
Ground Source Disadvantages
- Ground source heat pumps have high setup costs. Air source heat pumps cost less because you don’t need to setup a ground heat exchanger
- The type of bedrock can affect the amount of energy that can be produced when using a vertical ground source heat pump
- A horizontal ground source heat pump requires a lot of space since the pipes are spread out over a large surface
- Some liquids used when transferring heat are debatable as they raise environmental concerns, therefore ensure installation is done by certified individuals aware of regulations
Ground Source Heat Pump Efficiency
GSHP systems save energy by using the constant temperature of the ground to increase the efficiency of home heating. The source of heat used for ground source heat pumps is the sun, as it heats up the ground water resulting in the stable temperature of the Earth’s floor.
For every kW of electricity consumed by the heat pump, around 4 kW’s of heat is generated in return, meaning you have a 400% cost effectiveness ratio.
What do the COP and SCOP tell us about efficiency?
Ground pump systems reach rather high performance coefficients, with the average between 3 and 4. The Coefficient of Performance is found by dividing the useful heat output by the electrical energy input.
A ground source heat pump that transfers 4 kilowatts of heat from the ground for 1 kilowatt of electricity has a COP of 4. We recommend you check out the seasonal coefficient of performance (SCOP), as it is a more accurate representation of the efficiency during different times of the year, compared to the COP.
While the COP is the performance delivered at a specific moment, the SCOP will provide an average for the whole year, giving a more trustworthy figure.
What brands sell GSHP’s?
Ground source heat pumps differ in efficiency, price, and brands. Certain brands may have similar efficiencies and prices, yet some brands are available at higher costs than others.
There are many brands of ground source heat pumps available in the UK market, some of the most known brands include Baxi, Calorex, Bosch and Mitsubishi. Due to the large variety of brands available, it is important to compare supplier quotes to help make your decision easier when buying the best ground source heat pump. Ground source heat pump efficiency is improved by utilising solar recharge of the ground.
Ground Source Heat Pumps Explained
Ground source heat pump systems have three components:
- The heat pump
- The underground heat exchanger
- The distribution system
A mixture of water and antifreeze or refrigerant is pumped into the ground via the heat pump, and the antifreeze mixture is continuously warmed up by the constant temperature of the ground.
The liquid is fed into a heat exchanger and energy absorbed from the ground is transferred into a refrigerant which boils at a low temperature and turns it into gas.
The gas is fed into a compressor and the compressing process makes the temperature of the gas rise. The water is heated in the hydronic distribution system, where water is distributed to either radiators or floor heating.
Finally, the gas is transferred into a condenser, from which it delivers heat to serve the household’s space heating needs.
Installation of Ground Source Heat Pumps
House size and building requirements will determine whether a vertical or horizontal loop system is needed. The first step is the excavation of the loop fields.
To install a vertical ground source heat pump, the loop is placed in the drilled well that is dug deep into the ground. The heat exchanger is then installed in order to capture the heat from the ground.
For horizontal installation, a large area of land is dug up so that the loops can be placed across the land without having to dig deep into the earth.
Underfloor heating vs. Radiators
For maximum performance of your ground source heat pump, underfloor heating is ideal. Underfloor heating performs better than radiators because the heat is transferred equally across the whole surface, whereas radiators need to spread the heat from one corner to the entire room.
However, due to the higher cost of underfloor heating, radiators are also a good choice that results in high performance.
The SCOP is higher for underfloor heating compared to radiators because heat distribution is well designed with underfloor heating and therefore the floor system will likely have a lower output temperature than a radiator, meaning a higher coefficient of performance .
Heat Pumps Combined with Renewable Energy
Since electricity is required to run the heat pump, if you're not using renewable energy, it is not an entirely carbon neutral system. However, when heat pumps are combined with solar panels it is possible to reach a fully carbon neutral system.
It is important to note that special planning permissions are required in Wales and Northern Ireland, and in England and Scotland permissions depend on your location and the size of your property.
Incentives Available for Ground Source Heat Pumps
Are There Government Funds Available for Installing a GSHP?
Currently, the Renewable Heating Incentive pays 19.33 p/kWh of energy generated through ground source heat pumps. This is one of the highest tariffs you can get and after solar thermal panels at 19.74 p/kWh.
Payments are made on a quarterly basis over seven years. The amount of funds you receive will depend on a number of factors - including the technology you install, the latest tariffs available for each heating solution and - in some cases - metering.
If you are interested in buying the best ground source heat pump, we are here to help you. Simply fill in the contact form with your details and preferences and we will get back to you with customized, free, and no-obligation quotes!