Ofgem Minded to Back 16 Long-Duration Storage Projects With a Cap and Floor

Ofgem published its provisional list on 26 June: 16 long-duration electricity storage projects it is minded to support with a cap and floor scheme. Together they total about 7.65 GW. The decision is not final, and Ofgem expects to confirm awards in autumn 2026.

What Ofgem proposed

According to Energy UK's explainer, Ofgem provisionally selected 16 of the 73 eligible projects that applied to the first window. The portfolio totals about 7,645 MW of power and 136.9 GWh of storage, with discharge durations from 8 to 22 hours. Law firm Hill Dickinson reports the projects are in England, Scotland and Wales.

By technology, Energy UK counts 11 lithium-ion battery projects, 3 pumped storage hydro, 1 compressed air energy storage and 1 vanadium flow battery. Ofgem's consultation opened on 26 June, and the page we read says the final decision is expected in autumn 2026.

How a cap and floor works

A floor guarantees a project a minimum income, and a cap returns income above a set level to consumers. If revenue falls below the floor, consumers cover the shortfall through electricity bills. That is the trade: more investment in storage, with some risk moved from developers to bill payers.

We could not find an estimate of the total cost to consumers, and the explainer we read does not give one either. Our sources also differ on when the consultation closes, with 7 August in one and 14 August in another, so check Ofgem's consultation page before responding to it.

What it means for home battery owners

These are grid-scale projects, not household batteries, so nothing here changes how your own battery earns or saves. The link is indirect: more long-duration storage can help the grid handle windy or sunny spells, which is the same problem home batteries help with in a small way. See how this fits into the grid problem or solution debate.

If you want the household picture instead, our UK country guide covers rules, VAT and support, and dynamic tariffs are where a home battery can respond to the same price signals.

Sources

• Ofgem consultation: Window 1 minded-to decisions (long duration electricity storage)
• Energy UK: Long duration electricity storage and Ofgem's cap and floor decisions
• Hill Dickinson: Ofgem selects 16 long duration electricity storage projects for cap and floor support

Related guides

Keep reading, or check your own numbers:

• United Kingdom country guide
• Home batteries and the grid: problem or solution?
• Dynamic electricity tariffs are changing the role of home batteries