Heating accounts for more carbon dioxide (CO2) emissions than any other aspect of our lives for the average UK household. In order to reach net zero targets we’re going to need to dramatically reduce the amount of fossil-fuel generated heating ie gas or oil-fired boilers in our homes.
One way to do that is by installing a renewable heating technology, such as a heat pump, solar water heating or biomass boiler. Each home is different and you need to find out which technology will suit your home and your lifestyle.
If you’re not in a position to invest in a renewable heating system, don’t despair, you can still bring down your bills and reduce your carbon emissions by improving the insulation in your home.
In general, it is better to take an ‘insulation first’ approach to making your home more sustainable. Generating energy should be the final consideration, after you have done all you can to insulate your home. This is especially important to gain all the comfort benefits a heating system can bring.
Insulating your home effectively ensures that you keep the heat you generate in the house, rather than losing it through your roof, windows, doors or walls. The less heat you lose, the less you need to generate – some buildings that follow the Passivhaus principle do this so well that they barely need to generate any heat at all.
The Energy Performance Certificate (EPC) relating to your property may have some specific recommendations for your home when it comes to insulation. When you move into a property, you will receive an EPC as part of the paperwork associated with the move.
Find out more about the information on your Energy Performance Certificate and how it can help.
Which technology is right?
Air source heat pumps absorb heat from the air to heat your home – even when outside temperatures are as low as -15 degrees. Air source heat pumps require a place outside your home where you can fit the unit. A sunny wall with plenty of space around it to get a good flow of air is ideal.
Find out more about the installation costs and potential bill and carbon savings from air source heat pumps.
Ground source heat pumps use pipes buried in your garden to extract heat from the ground. You need plenty of outside space for a ground source heat pump, so they are ideal if you’ve got a reasonable garden, where you can dig a trench.
Find out more about the installation costs and potential bill and carbon savings from ground source heat pumps.
If you are considering a heat pump, you may want to read our blog about whether a ground source or air source heat pump is right for you.
Solar water heating
Solar water heating systems, also known as solar thermal, use heat from the sun to warm up water for your home. The system uses solar panels called collectors, which are fitted on to your roof. The panels collect the heat from the sun and use it to heat up water in a cylinder.
You’ll need around five square metres for the panels in a sunny location. The panels can be mounted on a roof, fixed to a frame on a flat roof or hung from a wall. You will also need space for an additional or increased size hot water cylinder.
Find out more about solar water heating systems.
Biomass systems burn wood pellets, chips or logs. While burning the wood does emit carbon dioxide, it is at a much lower level than coal or oil provided the fuel is sourced locally. Biomass is considered a sustainable option as long as new plants continue to grow in place of those used for fuel.
If you’re considering a biomass boiler, you will need space for the wood boiler itself, which would be bigger than a gas or oil equivalent, as well as space to store the fuel. You would also need a flue which meets the regulations for wood-burning appliances.
Find out more about biomass heating systems
Then, there are a number of options to choose from, which generate heat in different ways and can play different roles: providing hot water, space heating, or both.
The wood-fuelled systems that are eligible for the incentive are biomass boilers and pellet stoves, these supply all your heating needs. Solar thermal panels will provide hot water. Heat pumps are good for heating your home and are especially at providing low temperature heat, like underfloor heating. but are not as efficient at heating water too.
You’ll need to check that the renewable technology is on the official Product Eligibility List (PEL). The list shows which renewable heating systems are eligible for the scheme.
Financial support from the Renewable Heat Incentive
Installing renewable heating technology is a major investment. The government’s Renewable Heat Incentive (RHI) works in a similar way to the old Feed-in-Tariff system for renewable electricity. It offers quarterly cash payments over seven years for generating low carbon heat, which improves the return on investment. However, the scheme closes to new applications in March 2021.
If you’re intending to apply for the Renewable Heat Incentive, your home will need a certain amount of insulation to be eligible for the scheme.
What heating is already in place?
If you’re looking to replace your heating system with a low-carbon option in order to cut your home’s running costs, not just greenhouse gas emissions, it’s vitally important to consider the fuel you’ll be replacing, and the type of heating system you have.
In general, if you’re off the gas grid or replacing an electric heating system, renewable heating should be a good investment. However, if your home is served by the gas network and you’ve got a relatively new heating system in place, switching to renewable heating may result in increased fuel bills. It might be worth exploring other types of renewable energy, such as solar PV.
You should factor the heating system you’ve already got into your decision-making. Ground source heat pumps work better with underfloor or warm air heating systems, as opposed to radiators, due to the lower water temperatures needed. Solar water heating is compatible with most boilers and water cylinders, but this might not be the case with combi boilers.
Different renewable systems can complement each other. For example, solar water heating works well with heat pumps, because together they can provide efficient water and space heating. Of course, this is a more expensive route to take, so a lot will depend on your budget.
By installing a heat technology when you’ve already got work going on in your home you can save on installation costs – combining jobs and saving on disruption too. As with all big investments in the home, do plenty of research and ask potential installers questions.
The Russills, Fishguard, South Wales
Richard and his wife Sue built a new sustainable home off the gas network, so decided to invest in solar water heating and an air source heat pump rather than make an expensive connection to a gas supply some distance away.
Their builder, who had extensive experience installing them elsewhere, recommended the technologies. The fact it was a new build meant the installation could be neatly planned into the design. The building had the advantage of being well insulated, meaning the heat pump wouldn’t be overworked.
They had been worried about the noise of the heat pump after some stories from people who had installed older models, but have found the one they installed, which features serrated blades, to be virtually silent. They are also pleased with how the solar panels perform, despite South Wales’ often less than sunny climate.
They found registration for the Renewable Heat Incentive easy, with quarterly payments coming through reliably and without administrative burden.
To others considering investing in these technologies, Richard says: “Don’t be afraid. We had not used solar thermal or heat pumps before and they have exceeded our expectations.
“We used an installation contractor who not only has the relevant experience but also had a good working relationship with the equipment manufacturers. This ensured that they jointly come up with the best design for the project.”