Ground source heat pumps explained 

What is a ground source heat pump?

A ground source heat pump (GSHP) is a renewable energy system that uses the natural heat stored in the ground to provide heating and hot water for your home. GSHPs are highly efficient and can significantly reduce your reliance on traditional heating methods.

There are different types of heat pumps available, such as air source heat pumps and water source heat pumps, each with their own unique advantages.

How does a ground source heat pump work?

Ground source heat pumps work by circulating a mixture of water and antifreeze through underground pipes, absorbing heat from the earth and transferring it into your home.

When this heat is transferred to a heat exchanger inside your home, it’s increased to the desired temperature and distributed through radiators or underfloor heating systems.

Since the ground maintains a consistent temperature throughout the year, the system operates efficiently regardless of outdoor weather. Although the pump uses electricity, it relies on the earth's natural heat to warm your home effectively.

Different types of ground source heat pumps

There are two main types of ground source heat pumps, these are closed-loop and open-loop systems.

Closed loop ground source heat pumps

A closed-loop ground source heat pump uses a network of buried pipes filled with water and an antifreeze mixture to absorb heat from the ground and transfer it to your home. Unlike open-loop systems, which draw water from external sources, closed-loop systems rely on the consistent temperature of the earth for heat extraction. This system is ideal for properties with enough land for the underground pipes and doesn’t require access to groundwater.

Closed-loop systems are highly efficient and low-maintenance, making them a popular choice for eco-conscious homeowners. Whether installed horizontally or vertically, they provide a reliable, sustainable source of heating and hot water.

Open-loop ground source heat pumps

An open-loop ground source heat pump uses groundwater or surface water from a well, pond, or other natural source as its heat source. The water is drawn into the system, where the heat is extracted and transferred to your home for heating or hot water.

After the heat is removed, the water is returned to the ground or to the water source. This method differs from closed-loop systems, which rely on circulating fluid through buried pipes rather than using groundwater directly.

Open-loop systems are ideal for properties with access to an abundant and reliable water source. These systems can be more efficient than closed-loop systems due to the higher heat capacity of water, but they require careful consideration of local water availability and regulations. They are typically suited for areas where groundwater is plentiful and accessible.

Ground source heat pump advantages and disadvantages

Ground source heat pumps may not be the best fit for every household, so it's important to weigh their pros and cons before making a decision.

Ground source heat pump advantages

• High efficiency: Ground source heat pumps are incredibly efficient as they draw heat from stable temperatures underground.
• Low operating costs: Once installed, these systems typically result in lower energy bills due to their high efficiency and reliance on renewable energy sources.
• Long lifespan: Ground source heat pumps can last up to 25 years, and underground pipes often have a lifespan of 50 years or more.
• Increased property value: Installing a ground source heat pump can potentially boost your property’s value, as it’s seen as a green and energy-efficient feature.
• Grants and incentives: In many regions, homeowners may be eligible for government grants or incentives that can reduce the upfront cost of installation.
• Low carbon: Since they use renewable energy from the ground, ground source heat pumps contribute to a reduction in carbon emissions.

Ground source heat pump disadvantages

• High installation costs: The initial cost of installing a ground source heat pump is high due to the need for digging and laying underground pipes.
• Space limitations: These systems require a significant amount of space for the ground loops, making them unsuitable for properties with small gardens or limited outdoor space.
• Efficiency affected by soil type: The efficiency of the system can vary depending on the type of soil, with dry or rocky soils being less effective for heat transfer.
• Disruptive installation process: The installation can be invasive, requiring extensive digging or drilling and potentially disrupting landscaping.
• Long payback period: While operating costs are low, the payback period for the initial investment can take several years, especially if energy prices are low.
• Location limitations: Ground source heat pumps are not suitable for every location, particularly in areas with unsuitable ground conditions or limited space for installation.

What you need to know about installing a ground source heat pump

Do ground source heat pumps need planning permission?

Planning permission isn’t usually required for a ground source heat pump as they are classed as a permitted development. Open loop systems may not require planning permission, but you will need an environmental permit, consent and a licence before installing. Find out more about the process on the government website.

How much space do I need to install a ground source heat pump?

The amount of space needed for a ground source heat pump will vary depending on the type of system and the size of your property. But according to Heat Pumps UK, generally, the average horizontal ground source heat pump system will need around 700-800 square metres of space for installation.

How much does a ground source heat pump cost?

According to The Eco Experts, on average, ground source heat pumps cost between £24,000 and £49,000 to buy and install.

Does the government provide grants for ground source heat pumps?

Yes, the Boiler Upgrade Scheme run by the UK government, provides grants of up to £7,500 for air source heat pumps and ground source heat pumps.

Common questions about ground source heat pumps

What maintenance does a ground source heat pump need?

Just like all other types of heat pumps, a ground source heat pump must be serviced once a year to ensure the system is working efficiently.

Do ground source heat pumps provide hot water?

Yes, ground source heat pumps can heat water stored in a hot water cylinder, ready to use for your taps and showers.

Are ground source heat pumps efficient in cold weather?

Yes, ground source heat pumps are usually more efficient than air source heat pumps in cold weather.

Are ground source heat pumps more efficient than air source heat pumps?

Ground source heat pumps are usually more efficient over the year than air source heat pumps in colder temperatures.

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