While the UK government’s cap-and-floor scheme for long-term energy storage (LDES) is a good approach, there is lively debate about how much to purchase in the first window.
The subject was central to the ‘Advancing LDES: the perfect time to invest?’ discussion at the Energy Storage Summit 2026 in London in February, organized by our publisher Solar Media, part of Informa Markets.
The government released her list of projects eligible for the scheme in September last yearwith a target capacity of 2.7-7.7 GW with a capacity of more than 8 hours in the initial period. Of these projects, 70% are lithium-ion battery energy storage systems (BESS).
The panel included speakers from developer-operators Field and NatPower and energy storage providers Trina Storage, Fluence and Invinity Energy Systems.
In response to a question from moderator Cameron Murray of Energy storage.news, most, but not all, agreed that the government should be careful not to purchase too much capacity in this first round.
While the plan should certainly have a minimum capacity target to give the market confidence, you don’t want to purchase too much, says Nick Provost, sales manager of Trina Storage, the BESS arm of solar giant TrinaSolar.
“We think the cap-and-floor is well designed, but there will always be an unintended consequence that you can’t solve if we do too much too quickly,” Provost said. “2-3GW would be a reasonable outcome of the first round, which would be a good balance between providing market signals and protecting consumers.”
Brian Perusse, UK and Ireland MD for BESS integrator Fluence, agreed, saying that rather than procuring cargoes now, there should be smaller regular tenders that would also help build a sustainable industry.
“I would rather see 3GW every few years than, say, 7GW now,” he said.
Bex Sherwood, head of development at Field, also agreed. She said the current round appears to solve the challenge of interday storage, but not interweek or seasonal storage, which requires a much longer duration.
“The technology isn’t there yet, but we need to make sure we leave room for it and don’t over-purchase now,” she said.
However, NatPower MD John Sturman said he disagreed with most of these points.
“I agree that there are risks to over-purchasing LDES technology that need to be proven. I disagree with lithium-ion BESS,” he explained.
“We’re just doing more of the same for them. We’re already doing 2-hour BESS, all we would do is make it bigger. What we need to do is push the 2-hour BESS out of the network (the grid connection queue) and replace it with the 8-hour tasks.”
“For example, purchasing only 2GW in this first round is nowhere near what is needed. We have an ambitious Clean Power 2030 policy, and the supply and support must match that ambition. I see no risk in going big and hard for lithium-ion.”
Note that both Field and NatPower have sizable BESS projects that are on the list of eligible projects for the first window of the LDES scheme. NatPower has the most, though, and the plan appears to be core to its business model.
Interestingly, the risk of over-purchasing was mainly discussed in relation to whether this would be most cost-effective for the UK electricity bill payer who will ultimately fund this. Some short-term BESS owners, meanwhile, are opposing the scheme, saying it will have a negative effect on the continued development of short-term projects for tradersone of Britain’s clean energy success stories to date.
You can look at the full video recording of the panel discussion with a subscription to ESN premium here.
