Britain’s grid nearly buckled during last month’s heatwave. With temperatures topping 40°C in parts of England, demand for cooling, fans, fridges, pumps, pushed the system to within 1.5 GW of its safety margin. National Grid ESO issued three capacity notices in four days. The warning lights were flashing.
Now Ofgem has responded. The regulator has approved 16 new energy storage projects with a combined capacity of 2.1 GW, as reported by Proactive Investors. The projects, a mix of lithium-ion batteries, compressed-air storage, and pumped hydro, are built to soak up excess renewable power when the sun shines and release it when demand spikes. The first are due online by late 2026.
Why this matters for your electricity bill
Grid-scale storage does one thing that matters directly to households: it flattens price spikes. When demand surges on a hot afternoon, the marginal cost of the last unit of electricity can hit £400 per MWh, more than four times the average wholesale price. Storage can discharge at those moments, cutting the peak price and reducing the cost that suppliers pass on to customers.
Ofgem estimates that every 1 GW of new storage could shave roughly 1% off annual wholesale costs. On a typical household bill of £1,200 a year, that’s about £12 saved. Modest, yes, but the effect compounds as more storage comes online. The 16 projects add 2.1 GW, so the potential saving for a typical 3-bed semi is around £25 a year once all are operational.
The catch is timing. These projects won’t be live until 2026 at the earliest. Meanwhile, the price cap remains above £1,900 for a typical direct-debit household. Homeowners cannot wait that long for relief.
What it means for solar and battery owners
For households who already have solar panels and a home battery, the news is more directly useful. Grid-scale storage makes time-of-use tariffs more viable. Octopus Energy’s Flux tariff, for example, pays households to export power during peak windows, often 4pm to 7pm, and lets them import cheaply overnight. More grid storage means those peak windows become more predictable and more valuable.
Energy Saving Trust data shows a typical 4 kW solar system with a 5 kWh battery can save £300–£500 a year on a time-of-use tariff, compared with £180–£250 on a flat-rate tariff. The gap widens as grid storage grows, because peak prices rise higher and off-peak prices sink lower.
Homeowners considering a battery should note: the Smart Export Guarantee (SEG) currently pays 5–15p per kWh exported, but time-of-use tariffs can push that above 30p during peak hours. That changes the payback calculation. A 5 kWh battery costing £2,500 installed can pay back in 5–7 years on a time-of-use tariff, versus 8–10 years on standard export rates.
EPC impact and the bigger picture
Battery storage does not directly improve an EPC rating, the calculation is based on the building fabric and heating system, not on how you manage electricity. But it can reduce your grid electricity consumption during peak periods, which lowers your carbon footprint and your energy costs. Some assessors will note battery storage in the recommendations section of an EPC, which can help if you are selling.
The real gain is systemic. The more storage on the grid, the less need for gas peaker plants, those expensive, dirty units that fire up only when demand surges. Ofgem’s 16 projects could displace up to 1.5 million tonnes of CO2 per year, equivalent to taking 300,000 cars off the road. For the homeowner, that means a cleaner grid and, over time, lower carbon taxes embedded in bills.
The government’s Clean Power 2030 plan targets 20 GW of storage by the end of the decade. These 16 projects are a start, but industry analysts at Cornwall Insight say the UK needs at least 30 GW to fully stabilise the grid. Homeowners should watch the pipeline: more storage means cheaper, greener electricity for everyone.
What you can do now
If you have solar panels, check whether your supplier offers a time-of-use tariff. Octopus, EDF, and Ovo all have options. If you are considering a battery, get quotes from at least three MCS-certified installers and ask about export tariff compatibility.
For those without solar, the message is simpler: grid storage will slowly reduce your bills, but the big savings come from combining it with your own generation. The government’s Boiler Upgrade Scheme offers £7,500 for a heat pump, and solar-plus-battery can be added for around £8,000–£10,000. The payback, with rising grid storage, improves every year.
Ofgem’s approval is a signal, not a solution. The real test is whether these projects are built on time and whether the regulator approves the next 14 GW the grid needs. Homeowners should keep watching, and keep insulating, installing, and optimising tariffs in the meantime.
Frequently Asked Questions
No. The 16 projects are due online by late 2026 at the earliest. Once operational, they could reduce typical annual bills by around £25, but the main benefit is stabilising prices during heatwaves and winter peaks, which reduces the risk of sharp price spikes.
Now is a good time if you have solar panels and can access a time-of-use tariff like Octopus Flux. Grid storage will improve the economics of home batteries over time, but waiting means missing years of savings. A 5 kWh battery typically costs £2,500–£3,500 installed and can pay back in 5–7 years on a smart tariff.
