The price cap will rise by £63 in October, the third increase this year. But buried in the same Ofgem announcement is a quieter decision that could reshape how much households pay for electricity over the next decade. The regulator has named the winners of its long-duration electricity storage (LDES) support contracts, as reported by reNEWS. The winners include four projects that will store energy for up to 12 hours, using pumped hydro and compressed air, technologies that have been talked about for years but rarely built at scale.
What long-duration storage means for your energy bill
Britain’s grid currently relies on gas-fired power stations to cover the hours when wind and solar aren’t generating. That gas is expensive, wholesale electricity prices spiked to £400 per MWh during the 2022 crisis, and it adds roughly £120 a year to the average household bill, according to National Grid estimates. Long-duration storage replaces that gas with cheap, stored renewable power. Ofgem’s selected projects aim to deliver 2.5 GW of capacity by 2030, enough to power 2 million homes for several hours. The catch: these projects cost billions to build, and the support contracts mean network charges will rise slightly in the short term, about £5 per household per year, Ofgem calculates. But the long-term saving is larger: the Energy Systems Catapult says LDES could cut system costs by £3 billion a year by 2050, knocking £50 off every household bill.
Who qualifies, and who doesn’t
The four winners are all large-scale industrial projects: two in Scotland (pumped hydro at Cruachan and Coire Glas), one in Wales (compressed air at Rhyd-y-Groes), and one in England (a battery-plus-hydrogen hybrid in Yorkshire). None of them are roof-mounted batteries. For a typical 3-bed semi, the immediate impact is zero, you can’t buy a domestic version of this kit. But the strategic effect matters. When the grid runs on stored renewables rather than gas, the carbon intensity of electricity falls. That directly boosts the emissions savings from a heat pump or an electric car, making the case for those upgrades stronger. The Energy Saving Trust says a heat pump in a well-insulated home currently saves 2.5 tonnes of CO₂ per year; with a greener grid, that could rise to 3 tonnes by 2030.
What it means for your EPC and future upgrades
EPC ratings are partly based on the carbon intensity of the fuel you use. If grid electricity becomes cleaner faster than expected, thanks to storage allowing more renewables, the EPC score for an all-electric home improves. A property with a heat pump currently scores about 10 points higher on the EPC scale if it uses ‘green’ electricity versus the grid average. That difference could narrow as the grid decarbonises, but the absolute score rises. The Department for Energy Security and Net Zero confirmed in its 2024 consultation that EPC methodology will be updated to reflect real-time carbon intensity from 2026. So installing a heat pump now, while storage scales up, positions your home for a better rating later. The Boiler Upgrade Scheme offers £7,500 towards a heat pump, and that grant is not means-tested. Homeowners in England and Wales can apply through gov.uk from 4 November. Eligibility closes on 31 March 2027.
But will it work, and when
Ofgem’s support contracts are a start, but they cover only 2.5 GW. The Climate Change Committee estimates the UK needs 20 GW of long-duration storage by 2050 to meet net zero. The four projects won’t be operational until 2028 at the earliest. Meanwhile, the grid still burns gas for six hours a day on average, even on windy days. The real test is whether the government will expand the LDES scheme to more projects and faster timelines. If it does, household bills could fall by £50 a year by the mid-2030s. If it doesn’t, the gas price risk remains. Homeowners can hedge that risk today by improving insulation, the cheapest way to cut energy use, and by switching to a time-of-use tariff that rewards off-peak charging. Octopus Energy’s Agile tariff, for example, has seen rates as low as 5p/kWh at 2am, when wind power is abundant. Pair that with a battery and solar panels, and you’re effectively running your own long-duration storage at home.
Households on standard variable tariffs should check if they can switch to a smart tariff that aligns with renewable generation. The Energy Saving Trust has an online tool to compare tariffs. For those considering a heat pump or solar panels, the Boiler Upgrade Scheme and the Smart Export Guarantee remain the main financial supports. Apply before March 2027 to secure the grant.
Frequently Asked Questions
No. The projects won't be operational until 2028 at the earliest, and network charges will rise slightly, about £5 per year, to fund them. But by 2035, savings could reach £50 per household annually as gas use falls.
No. The Boiler Upgrade Scheme is separate from grid-level storage. You can still apply for £7,500 towards a heat pump, regardless of Ofgem's LDES decisions. But a greener grid makes heat pumps more efficient and better for your EPC rating.
