Heat Batteries: Decarbonising Homes

Tom Hayes Excerpts

Wednesday 8th January 2025 Westminster Hall

[Deirdre Costigan]

As I have laid out, the Government have already taken steps to increase the funding to transition to heat pumps. I am sure the Minister will have more to say on rural communities and the particular barriers they face.

Although heat pumps are extremely important in the move to wean us off gas, they do not work for every home. An estimated 20% of homes are unsuitable for heat pumps. We need to do more to break down the reasons why people can be reluctant to choose them. Air source heat pumps need outdoor space. Many of my Ealing Southall constituents live in small terraced homes or flats and do not have much outdoor space, so a heat pump is not a viable or attractive option. Many people have repurposed the space that used to house their hot water tank.

That is where innovative British firms such as Kensa in Cornwall and Tepeo in Reading come in. Both companies use heat batteries, using the same science that is behind hand-warmer packs, to store thermal energy until it is needed. Tepeo’s zero emission boiler, ZEB, uses a heat battery that automatically buys energy at cheaper times of day and releases it when required, reducing energy bills. Users do not need an outside pump; they just need a box about the size of a gas boiler. Because of their small size and their ability to plug and play without needing to do replumbing, heat batteries are a good solution for heating homes in built-up urban environments like London, including parts of Ealing Southall.

Kensa uses shared ground source heat loops that are connected to whole streets or blocks of flats. The energy is connected from the ground, is produced in networked heat pumps in each of the linked houses or flats and is then stored in Kensa’s Sunamp heat batteries. No outdoor space is needed, and it replaces the need for a hot water tank.

[Tom Hayes (Bournemouth East) (Lab)]

Will my hon. Friend give way?

[Esther McVey (in the Chair)]

Order. Before the hon. Gentleman intervenes, may I remind Members that interventions should be concise and should not be speeches?

[Tom Hayes]

I thank my hon. Friend for securing this debate. I was lucky recently to visit Kensa’s air source heat pumps in Sutton Dwellings in Chelsea. I have also visited Tepeo’s factory; it is great to see the chief executive officer in the Public Gallery today. Does my hon. Friend agree that for heat batteries to enjoy the same penetration of the market as heat pumps, it is important that they benefit from VAT relief and the same levels of subsidy so that we can decarbonise our heating?

[Deirdre Costigan]

I absolutely agree, and I will come on to exactly those points. Kensa’s approach also uses ground source heat technology, aligned with heat batteries—a cheap and efficient way of rolling out heat pumps at scale. My hon. Friend mentions a visit he made; another example is that Kensa has replaced direct electric heaters with shared ground loops alongside heat batteries in more than 270 flats across three tower blocks in Thurrock. Residents’ bills have reduced by more than 60%, which is a huge saving. Both those technologies can wean us off gas. They are examples of the kind of British manufacturing and innovation that we need to support to create good-quality jobs. However, barriers remain, and I hope that the Minister will consider ways of addressing them.