According to the National Audit Office, home heating represents 18% of UK greenhouse gas emissions. The government is under huge pressure to reach environmental targets in its commitment to Net Zero, and sees heat pumps as the best way of cutting our emissions. Heat pumps are 3 times more energy efficient than traditional gas boilers so can substantially reduce the carbon footprint of homes throughout the UK, and the government’s independent climate advisers have said that approximately half of all homes in the UK will need to have a heat pump installed by 2040 if they are going to meet demanding targets.
Here we’re going to take a close look at heat pumps and explore the different types, look at how they work, the grants available, and, as they’re not suitable for every property which is particularly true to typically older off-grid properties facing their own challenges, look at low-carbon alternatives such as LPG and renewable gases with which to heat your home as we all move towards a lower carbon future.
Heat pump uptake in the UK
Uptake has been slow. In a 2024 press release, the National Audit Office reported that the number of heat pump installations by December 2023 was less than half of the planned projections. However, latest figures show a record number of government-supported heat pumps were installed over the last 12 months in the UK, with the BBC reporting earlier this month that 52% more heat pumps were installed than in 2023 with just short of 100K being installed in total last year:
How heat pumps work
Heat pumps are low-carbon heating systems that run on electricity to take heat from the air or ground and transfer it to your home to provide heating and hot water. They basically work like a fridge, only in reverse.
There are two main types of heat pumps, an air source heat pump (ASHP) or a ground source heat pump (GHSP). The most common types of heat pumps in the UK are the air source heat pumps as they’re usually less expensive to install. Plus, ground source heat pumps need a lot of space as they require a big hole boring into the ground, and there can also be planning permission issues for instance if you live in a listed building or a conservation area.
The main difference between these two types of heat pump is that ASHPs absorb heat from the air around the unit, whereas GSHPs absorb heat from the ground through underground pipework. Both take the heat and raise its temperature through a heat exchanger before transferring it to your central heating system.
The type of heat pump that’s right for you will depend on your home, how much space you have and your budget. They work best in airtight, highly insulated homes and you do need outdoor space, with ample airflow to accommodate the unit and allow access for maintenance.
Heat pump efficiency
Heat pumps run on electricity and, as The Energy Savings Trust reports, for every unit of electricity used, you can get three to four times as much heat. How much money you will save will depend on what heating system you’re replacing, and if you have a newer A-rated heating oil or LPG boiler, heat pumps are likely to be slightly more expensive to run as can be seen from the graph below:
Source: Energy Savings Trust
Savings for Great Britain are based on an electricity price of 24.5p/kWh and a mains gas price of 6.29p/kWh, calculated from a weighted average of projected current and recent energy price caps.
We're all feeling the pinch as our bills go up and up, and households are looking more than ever at how they can be cost-effective. Whilst heat pumps are efficient, energy tariffs are constantly changing and as they run on electricity, it’s difficult to determine how much you would save. Plus savings also depend on the type of your property.
Installing a heat pump – the costs
Whilst heat pumps can potentially save on running costs, they are not cheap to install, which can be a major hurdle in persuading homeowners to make the switch with many sceptical as to whether they’re worth the cost. Plus the substantial upfront costs, which can vary based on the system and the complexity of the installation, mean they are unaffordable for many.
According to the Energy Savings Trust, air source heat pumps cost around £14,000 to install, whereas ground source heat pumps, which should be considered as a long-term investment, cost from £28,000 upwards, depending on whether you need to dig a borehole which can increase the cost to as much as £57,000.
Apart from high upfront costs, there are other things you need to think about. Such as, do you need to alter your home? For instance, if you live in an older home, you may need to make home improvements to add in a lot more insulation, and you will need bigger radiators and underfloor heating to generate an equivalent amount of heat and hot water as is produced by a traditional oil or LPG boiler.
What grants are available?
Whilst installing a heat pump is expensive, there is government funding available.
In England and Wales, the government has introduced the Boiler Upgrade Scheme which provides a grant of £7,500 to homeowners to help with the cost of upgrading from a fossil fuel boiler to a low-carbon alternative like an air source heat pump. Fossil fuel heating systems include LPG, mains gas, oil and electric.
However, there are a lot of boxes to tick to be eligible, and there’s still a big amount to pay on top of the £7,500 grant. You need to own your property so if you’re in social housing or rent, you won’t qualify. You need to be replacing a fossil fuel system, e.g. an oil or LPG boiler, and your property must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation.
The Home Energy Scotland scheme and loan service is a similar scheme for people living in Scotland. Once again there are grants of up to £7.5k (or 9K in some remote areas), but on top of that, there is an additional £7.5K available as an interest-free loan. The more you need to borrow, the longer the maximum term of the interest-free loan. Again, you need to own your home, (although it’s not available to landlords, businesses or property developers), and you’ll need an Energy Performance Certificate for your property before and after the installation.
There is help available for properties that require energy efficiency upgrades under The Energy Company Obligation (ECO) which is a government energy efficiency scheme in the UK which aims to tackle fuel poverty and help reduce carbon emissions.
You must own your home or have permission from your landlord to benefit from the scheme, and you could be eligible if you receive certain benefits or if someone in your home has a severe or long-term health condition that is affected by a cold home. The Energy Saving Genie has a useful online eligibility checker.
Clean, green alternatives
With potentially prohibitive high up-front costs, for many households it’s important to consider the alternatives to heat pumps as they’re not for everyone or every home. If you’re concerned about the high up-front installation costs, liquid petroleum gas (LPG) and soon to come renewable gases could be the perfect solution for you.
LPG is versatile and provides high-temperature heating, hot water, and an instant flame for cooking too. It’s also cleaner that other conventional off-grid fuels.
BioLPG and rDME, both environmentally friendly versions of traditional LPG, offer a more cost-effective alternative to installing a heat pump. Both are drop-in solutions so, once available, can be used in existing systems without having to make any changes, so no retrofit or replacement costs, and no need for expensive home improvements or new equipment. And they’re efficient and sustainable, providing key future solutions for decarbonizing off-grid homes throughout the UK. Great news for the future of gas boilers and renewable gases!
For more information on how you can improve your carbon footprint, contact us on 01423 772 789.