UK Backs Eos Zinc Storage in Ofgem's Long-Duration Shortlist
Two Scottish projects using US firm Eos's zinc battery technology secured provisional cap and floor support, the first such regulatory backing in Britain for the chemistry.
Ofgem provisionally placed sixteen long-duration energy storage projects on its cap and floor shortlist on Tuesday (2026-06-30), with two of those schemes set to deploy zinc battery technology from American firm Eos — the first entry for that chemistry into a British regulated revenue framework.2
The two Eos-technology projects, the 200 MW/1,600 MWh Ayr scheme and the 150 MW/1,200 MWh Busby project, each deliver eight hours of storage duration, double the four-hour standard common in most lithium-ion grid deployments. Cap and floor regulation guarantees minimum revenues when prices are low while capping returns in high-price periods, a structure designed to make projects of this scale financeable where merchant revenues alone would not attract debt.2
Developer Field ran the table on Ofgem's shortlist, securing all five of its LDES submissions. The company emerged with a combined 1.6 GW and more than 26 GWh of provisionally supported capacity across four Scottish projects and one in East England — the single largest total from any applicant in the round.2
The sixteen-project shortlist spans several storage technologies. Alongside the Eos zinc schemes and Field's lithium-ion projects, Ofgem provisionally backed Statera Energy's 600 MW Loch Kemp pumped storage hydro project on the shores of Loch Ness, as well as Storelectric's TeesCAES project on Teesside. TeesCAES has a power capacity of 50 MW and 30 hours of storage — the longest duration on the shortlist — implying 1,500 MWh of energy capacity. Other shortlisted lithium-ion projects included Statera's 500 MW East Claydon and 500 MW Sundon Storage sites, Gresham House's 100 MW Ocker Hill, and Innova's 507 MW Drakelow scheme.2
Storelectric managing director Tallat Azad said the outcome was a "strong endorsement" of TeesCAES and reflected "the critical role CAES will play in enabling" the energy system. Field described the result as providing "significant confidence to the supply chain in the long-term viability and momentum" of its projects, language that points to the contractor and investor hesitation that has slowed procurement across the sector.2
That hesitation has been global. Panelists at the BloombergNEF Summit in New York in April noted that despite strong demand for battery storage, high battery pack prices, shipping bottlenecks and supply chain constraints were dampening near-term deployments. The Ofgem framework, by anchoring revenues across a project's operating life, is partly designed to insulate British schemes from those dynamics — though the policy structure cannot resolve supply chain tightness directly.1
NatPower signed a multi-year supply and execution agreement with Tesla covering more than 25 GWh of battery storage capacity, announced the same week (week ending 2026-07-01). The scale of that agreement — one of the largest single procurement deals of its kind in Europe — suggests that some developers are moving ahead on supply contracts without waiting for final cap and floor decisions.2
Provisional listing is not the same as final support. The road from shortlist to investment decision runs through planning consents, grid connection agreements and technology supply contracts, and previous rounds have seen attrition at each stage. Zenobe, the battery developer, lost a legal challenge to Ofgem's selection process this week (week of 2026-06-30), which the regulator said reinforced the soundness of its methodology. How many of the sixteen provisionally supported projects convert that status into committed financing is what the programme's next phase will determine.2