Heat Batteries Move Closer to Boiler Upgrade Scheme Support: What Homeowners Need to Know

What Parliament debated this week

On 14 October 2026, MPs considered the Draft Boiler Upgrade Scheme (Amendment to the Energy Act 2008 etc.) Regulations 2026. The central purpose of the regulations is to add thermal energy storage to the categories of technology that the Boiler Upgrade Scheme can legally support.

That creates the statutory foundation for the government to offer grants for eligible heat batteries at a later date. Without this amendment, the scheme would not have the necessary legal scope to fund them.

The debate also covered administrative changes, including provisions allowing Ofgem, which administers the scheme, to recover payments made incorrectly or where eligibility conditions were not met. Although that sounds procedural, it is important for homeowners and installers: future applications will need accurate property details, compliant products and a clear installation record.

Ministers stressed that funding would not begin until suitable product, installation and safety standards were in place. MPs also raised questions about safety and the complexity of the drafting. Those concerns reflect the fact that “heat battery” covers a developing group of technologies rather than one universal type of appliance.

What is a heat battery?

A heat battery stores energy in the form of heat and releases it when a home needs space heating or hot water. It performs a similar time-shifting function to an electrical battery, but it stores thermal energy rather than retaining electricity for later use as electricity.

Different products use different storage materials. Some rely on high-density ceramic or mineral cores, while others use phase-change materials that absorb and release substantial amounts of heat as they change physical state. A conventional hot water cylinder is also a form of thermal storage, although modern heat batteries may store more usable energy in a smaller space and may not hold a large volume of domestic water.

A heat battery can be charged when electricity is cheaper, when renewable generation is plentiful or when another heat source is operating efficiently. The stored energy can then be released during periods of higher demand. Depending on the design, it may provide domestic hot water, feed a wet central heating system or support another heating appliance.

This does not mean every heat battery can replace every boiler. Some products are designed mainly for hot water, some for space heating, and others work as part of a hybrid system. Output rate is just as important as storage capacity: a battery may hold enough total energy for a household but still be unable to release it quickly enough to meet simultaneous shower, hot water and heating demand.

Why the change matters for UK homes

Heat pumps are likely to remain central to the transition away from fossil-fuel heating, but they are not the only useful technology. Some homes have restricted outdoor space, difficult planning considerations, unusual heat-demand patterns or electrical and fabric constraints that make a straightforward heat pump installation more involved.

Thermal storage may provide another route, particularly where households can shift electricity use away from expensive peak periods. It can also help the electricity network by reducing demand at the times when millions of homes would otherwise be calling for heat simultaneously.

For homeowners, greater choice is welcome, but choice also creates a need for careful system design. A heat battery should not be selected simply because it is compact, quiet or potentially grant-funded. The installer must establish how much heat the building loses, how much hot water the occupants use, how quickly the stored heat must be delivered and how the unit will be recharged.

The technical checks that will determine whether it works

The starting point for any low-carbon heating design is a room-by-room heat-loss calculation. This estimates how quickly heat escapes through walls, windows, roofs, floors and ventilation when outdoor temperatures fall. The result determines both the required heating output and the likely daily energy consumption.

Storage must then be sized in kilowatt-hours, while its maximum output is measured in kilowatts. These figures are related but not interchangeable. Capacity tells you how much heat can be stored; output tells you how quickly it can be delivered. A large store with inadequate output may struggle on a cold morning, while a high-output unit with insufficient capacity may run out before the next charging period.

The property’s electrical supply also needs checking. Electrically charged thermal storage can create a substantial load, particularly when combined with an electric vehicle charger, induction hob or electric shower. The consumer unit, cable sizes, earthing arrangements and main supply capacity must all be suitable. In some cases, the local electricity network operator may need to be notified or asked about an upgrade.

Controls and tariffs are equally important. The financial case may depend on charging during lower-cost periods, but cheap-rate windows vary between tariffs and can change over time. Controls must balance tariff periods, weather forecasts, household routines and the amount of heat remaining in the store.

What it could mean financially

The draft regulations do not confirm a heat battery grant amount, a start date or the detailed eligibility conditions. They should therefore not be treated as a promise that a particular product purchased now will receive funding retrospectively.

Future support could reduce the upfront cost, but installation price is only one part of the financial assessment. Homeowners should also consider annual electricity consumption, tariff availability, maintenance requirements, expected product life and whether other work is needed to the electrical installation, radiators, controls or insulation.

A heat battery charged entirely at a standard peak electricity rate may have very different running costs from one managed around a suitable time-of-use tariff. Likewise, replacing a gas boiler in a poorly insulated house with direct electrically charged storage could increase bills if the system and tariff are not carefully designed.

Households should be cautious about sales claims based only on headline savings. A credible proposal should show the building’s calculated heat demand, the assumed electricity price, charging schedule, standing losses and expected backup energy use. Comparisons should use the home’s real gas and electricity consumption where possible, rather than relying solely on a generic property example.

What the proposal means locally

The housing stock around Bordon, Whitehill, Liphook, Alton, Farnham and Haslemere is extremely varied. It includes newer estates built to relatively modern insulation standards, post-war homes, rural cottages, large detached properties and period buildings with solid walls.

That variation will have a major effect on whether thermal storage is practical. A well-insulated modern home in Bordon or Whitehill may have a modest and predictable heat requirement, making it easier to store enough energy during an off-peak charging window. A larger solid-wall property near Alton, Farnham or Haslemere may lose heat much faster and require considerably more storage capacity and electrical input.

Rural properties around Liphook and the surrounding villages may also be using oil, LPG or direct electric heating rather than mains gas. Heat batteries could eventually give some of these households another option, but the economics must be compared against their existing fuel, the condition of the heating system and possible heat pump solutions.

Space is another local consideration. Compact thermal storage may appeal where there is no room for a traditional hot water cylinder, but installation still requires safe access, adequate structural support, ventilation where specified by the manufacturer and suitable pipe or cable routes.

What homeowners should do now

There is no need to rush into buying a heat battery because of this parliamentary development. The regulations establish a route towards future support; they do not make every thermal store immediately eligible for a grant.

• Wait for confirmed government and Ofgem guidance before relying on grant funding in a financial plan.
• Do not assume that a product will qualify retrospectively unless the published scheme rules explicitly say so.
• Gather at least 12 months of gas, oil and electricity usage so proposed systems can be compared against real consumption.
• Arrange a proper heat-loss assessment before selecting the size of any heat pump, electric boiler or thermal store.
• Check insulation, draughts and heating controls first, because reducing heat loss can reduce the size and cost of the equipment required.
• Ask for both storage capacity and maximum output, together with a clear explanation of what happens if the stored heat is exhausted.
• Ensure any quotation identifies electrical upgrade costs, tariff assumptions, warranties and ongoing maintenance requirements.

If a boiler has become unsafe or unreliable, homeowners should not postpone essential work solely in anticipation of an unconfirmed grant. A repair, a modern boiler, a heat pump or a future heat battery can only be judged properly after considering the property, budget and expected length of ownership.

Safety and standards will be decisive

The government’s emphasis on standards is sensible. Thermal stores can contain very high temperatures and significant amounts of energy, so products need dependable insulation, over-temperature protection, safe controls and clear provisions for faults or power interruptions.

Installation standards will also need to address electrical protection, hydraulic design, commissioning and installer competence. Future Boiler Upgrade Scheme rules are likely to specify approved technologies and evidence requirements rather than allowing grants for any device marketed as a heat battery.

For homeowners, the key message is that this week’s development is promising but preliminary. Heat batteries could become a useful additional tool for lower-carbon heating, especially in homes suited to off-peak charging, but they will not remove the need for accurate calculations and competent installation.

Discuss your home’s heating options with Embassy Gas

For practical advice on boilers, heat pumps, heating controls and future-ready system design in Bordon, Whitehill, Liphook, Alton, Farnham and Haslemere, call (01420) 558993, email helpdesk@embassygas.com or book online at https://www.embassygas.com/book.