There is huge potential for heat pumps to help decarbonise domestic heating within the UK. One way is to use renewable energy provided through smart local energy systems, but consumers will need to feel confident that heat pumps can deliver the comfort they desire, before they are willing to remove their gas boilers.

This report documents an approach taken by Energy Systems Catapult to encourage adoption of a low carbon heating system and proposals for how the barriers to wider scale adoption could be overcome.

The work was carried out by the Consumer Insight team in the Living Lab for the Energy Revolution Integration Service as part of the Prospering from the Energy Revolution programme. It builds on work delivered in the Smart Systems and Heat programme.

Key points

The UK has one of the largest and most valuable gas boiler markets in the world, with more than 24 million homes, businesses and industrial users being reliant on natural gas for heating. This equates to around 84% of all UK households, showing how strongly consumers have favoured gas boilers over other heating options.

Air source heat pumps offer one of the more viable low carbon alternatives to gas central heating. This is because they can be run on low carbon electricity, are generally more efficient than gas boilers, can connect to the existing home plumbing, and can even result in lower energy bills if a home is insulated sufficiently.

As of October 2018, there are approximately 46,000 heat pumps installed across the UK, with experts predicting the heat pump market will double by 2025. This uptake will need to increase significantly if the UK is to accomplish its carbon emissions target, with the Committee on Climate Change highlighting that 17 million heat pumps would be needed by 2050 to meet this target in their core scenario.

What we did

Step 1: Gas boiler to a hybrid heating system

We recruited five participants willing to install a heat pump at their property. The heat pump was paired with their existing gas boiler to create a hybrid heating system. Participants were given smart heating controls, which enabled them to individually control the heat in different rooms.

Step 2: Hybrid heating system to solely heat pump

After one year, participants were given the option to trial heating their home using just their heat pump for a six-week period. All five indicated they were keen to take part. None had experienced heating with only their heat pump previously. Participants were also given cost information to help estimate how their energy costs could change.

What we saw

• Four participants managed to get as comfortable (or better) with a heat pump as they had with their gas boiler. The fifth experienced comfort issues specific to an inefficient room.
• Two reported improved comfort when heating with a heat pump. Both indicated that they had scheduled their heating for longer periods to support the heat pump, resulting in a more consistent temperature. In one instance, a participant simply chose to be warmer when using the heat pump as they did not think it would harm the environment.
• The heat pump took longer to warm some rooms up and struggled to heat thermally inefficient rooms. Some participants preferred to turn their heating off early in the morning to avoid the noise, even if this meant being cold. Others reported feeling colder than when using the hybrid system when they were less physically active.
• The year spent heating their homes with a hybrid heating system gave participants the confidence to trial heating with only a heat pump. This was because it provided a chance to explore whether heat pumps could meet their needs before removing their existing boiler.

What you should consider

• Heat pumps are new and unfamiliar to consumers, so consider how you introduce them to consumers. To give consumers confidence to purchase, provide information about how heat pumps work and perform, using familiar language where possible.
• Help consumers achieve positive early experiences. Explain what the installation will involve, so consumers expect the disruption. Advise on the types of heating schedules they should consider, to ensure they can get comfortable.
• Persuade consumers to heat for the longer periods, often better suited to heat pumps, by introducing financial safety nets.
• Regularly check the system is working properly to boost consumers’ faith in the technology. Ensure you have demonstrated that heat pumps can deliver the heating consumers desire without the gas boiler, prior to removing the boiler.