Ofgem Names 16 Long-Duration Storage Projects for First Cap-and-Floor Window, 7,645 MW Led by Three Pumped-Hydro Schemes
Britain's energy regulator is minded to back 16 long-duration storage projects totaling 7,645 MW, with pumped hydro and batteries dominating a portfolio meant to soak up excess wind.
Overview
Britain’s energy regulator has provisionally selected 16 long-duration storage projects for support under the first window of its new cap-and-floor scheme. According to Ofgem, the regulator “has identified 16 projects creating an LDES portfolio” spanning four technologies, and opened a consultation on the minded-to decision that runs until 7 August, with final determinations expected later this year. The chosen projects total 7,645 MW of capacity, as reported by Energy-Storage.news.
What We Know
The cap-and-floor regime is designed to make long-duration storage financeable by guaranteeing a revenue floor while capping the upside. Ofgem defines the floor as a minimum revenue: “If the project’s revenue falls below this floor, consumers pay the LDES operator the difference up to the floor level,” according to Ofgem. The cap works in the other direction, setting a revenue ceiling “above which projects pay money to consumers if they end up making more than is considered a fair rate of return on invested capital.” The regulator defines long-duration electricity storage as systems “that can store and release electricity for long periods, defined as eight hours or more.”
The portfolio is dominated by pumped hydro and batteries. Per Energy-Storage.news, the selected projects range from 8 to 22 hours of duration and were chosen from 77 previously shortlisted projects totaling 27 GW; the 7,645 MW selected sits at the top of Ofgem’s guided 2.7-7.7 GW range for the first window. The technologies involved include lithium-ion battery energy storage, pumped storage hydro, compressed air energy storage and vanadium redox flow batteries.
The technology split breaks down into three pumped hydro projects, one compressed air storage scheme and 12 long-duration battery projects, of which 11 are lithium-ion and one is a vanadium flow battery, according to Proactive Investors. The same report notes the differing economic-life assumptions Ofgem applied: 40 years for pumped storage hydro, 30 years for the vanadium flow battery and 25 years for lithium-ion.
The three pumped-hydro schemes carry the bulk of the energy. According to International Water Power, they are the 1,800 MW Earba project from Gilkes Energy, SSE Renewables’ 1,440 MW Coire Glas and the 660 MW Loch Kemp Storage scheme, together accounting for 3,900 MW of pumped storage hydro with approximately 87 GWh of storage. The same outlet reports the portfolio also includes the 50 MW TeesCAES compressed air energy storage project alongside lithium-ion battery developments across Scotland, England and the Midlands.
Coire Glas, on the shores of Loch Lochy in the Scottish Highlands between Fort William and Inverness, would on its own be “Great Britain’s largest energy storage project if delivered,” according to the Coire Glas project, which states the SSE Renewables scheme “would provide at least 45GWh of long duration electricity storage.”
Geographically, the projects are “spread across Scotland and England, with one proposed VRFB project selected in north Wales,” per Ofgem, with the majority of capacity concentrated in Northern Scotland, as reported by Energy-Storage.news.
Akshay Kaul, Ofgem’s Director General for Infrastructure, framed the decision as a step toward a cleaner grid. “This takes us a step closer towards the long-duration energy storage we need in a clean power system to maintain secure supply,” he said, according to Ofgem. Among developers, Field chief executive Amit Gudka called the regime “a global landmark scheme,” as reported by Energy-Storage.news.
What We Don’t Know
The decision is a minded-to position, not a final award; Ofgem’s consultation remains open until 7 August before final determinations, according to Ofgem, so the project list and supported capacity could still change. Construction timelines, final cap and floor levels for each project, and the ultimate cost to consumers were not detailed in the announcement.
Analysis
The geographic concentration in Northern Scotland mirrors the structural mismatch in Britain’s grid: that is where wind generation is most abundant, but transmission capacity to move it south to demand centers is constrained. The pressure was visible the same week the decision landed. According to Proactive Investors, during a heatwave “low wind speeds and soaring electricity demand forced gas plants to provide more than half of Britain’s electricity on peak days” — the kind of multi-hour gap that eight-hour-plus storage is meant to fill.