The Energy Saving Trust published research on 12 August 2026 examining how heat pumps, solar panels, batteries and energy tariffs perform together. The study used measured performance data from 546 homes and looked at around 1.1 million combinations using a full year of data1.
The central finding concerns tariffs rather than hardware. Most heat pumps on a standard flat-rate tariff cost the same or more to run than an efficient gas boiler, the research found, while switching to a heat pump appropriate tariff can save up to £330 a year on heating bills1. The Trust defines heat pump appropriate tariffs as dedicated specialist heat pump tariffs and dynamic tariffs, where the cost of electricity can change every 30 minutes. Dynamic tariffs often performed similarly to specialist heat pump tariffs1.
On payback, the Trust used a typical heat pump cost of around £11,700 and added the £7,500 discount available in England, Wales and Scotland through the Boiler Upgrade Scheme and the Home Energy Scotland Grant and Loan. It also counted the avoided cost of replacing a gas boiler, around £3,700 on average, bringing the additional cost of a heat pump down to £5001. Where a household moves fully away from gas for heating and cooking, avoiding the gas standing charge is worth around £105 a year based on July 2026 prices1.
The research also compared battery pairings. It found batteries are better paired with heat pumps than with solar panels, assuming an appropriate tariff, because batteries can draw electricity from the grid during off-peak periods and store it for the heat pump to use instead of peak-rate electricity1. For solar and battery combinations, the Trust states that current solar export tariff rates are good enough that a household can save almost as much by selling excess electricity at peak times, so the extra money made by adding a battery may not justify the cost1.
Combining heat pumps, solar panels and batteries with the right tariffs, described in the research as an integrated electric home, reduced energy bills by around £800 a year in general, with the best-performing combinations saving around £1,000 or more. In those strongest scenarios, heating bills fell by almost 80%1.
"Our energy experts designed this research to reflect real homes and real systems."
The Trust states that all savings shown are scenario-based, and that actual outcomes depend on the home, system performance and choice of tariff1. It also notes that even the best tariff cannot fully protect against a badly performing heat pump, and that an MCS installer is needed to take advantage of any available grants1.
Why it matters for households
For a household weighing up a heat pump, the research indicates that the running cost comparison against a gas boiler depends heavily on which heat pump electricity tariff is in place, not only on the efficiency of the unit. A time-of-use tariff shifts consumption to cheaper periods, and the research found dynamic tariff performance broadly matched specialist heat pump tariffs. For homes with solar and storage, the finding that a battery pairs better with a heat pump than with panels alone changes the order in which technologies pay back, which bears on whether to add solar and a battery alongside a heat pump. The Trust also identifies a gap: there is currently no robust service for comparing tariffs matched to renewable technologies, so households must research options themselves1.
What happens next
The Trust says its energy experts are working on a next phase covering the impact of renewable technologies on private tenants and social housing, the effect of electric vehicle charging within these systems, updated information on tariff choices, improved analysis of battery charging patterns, and the impact of these scenarios on carbon footprint1. No dates have been reported for that work. The research also points to the Warm Homes Plan, which the Trust says includes fully funded support for low-income families worth up to around £12,000 and low and zero-interest loans for homeowners regardless of income1.
Sources1 cited
- How to make renewable technology more affordable - Energy Saving Trust, energysavingtrust.org.uk