Energy storage company Zenobē is currently legally challenging the LDES (Long Dur Energy Storage) cap program, claiming it unfairly favors LDES technologies.
The company took the case to the Competition Appeal Tribunal in late October 2025, after previously raising public concerns about the design of the cap and floor scheme. Court documents show the company claims the plan’s design “threatens to distort competition” by pitting subsidized LDES projects against unsubsidized lithium-ion BESS projects.
Zenobē told the Tribunal that by giving subsidized LDES projects access to the same markets as established short-term technologies, Ofgem risked “creating an uneven playing field that undermines the investment rationale for [short-duration] technologies” and by allowing LDES projects to “displace” other forms of energy storage.
The cap-and-floor arrangement guarantees a minimum revenue level for LDES projects and limits their maximum revenues to a predetermined level, with the aim of making them more viable.
When it launched the schemethe government suggested that the cap and floor would support technologies that could not be financed under existing market conditions, and that more established energy storage technologies – particularly lithium-ion BESS – would be excluded. However, when the first window of the plan closed, the net was over 70% of successful projects used lithium-ion technology.
In a public statement, Zenobē said it “fully supports the UK government’s ambition to deliver affordable, clean and safe energy” and that LDES “will play an important role” in the government’s objectives.
In April 2025, Zenobē’s founder said, James Basdentold our sister publication, Energy storage.newsthat “no one has really thought about… how we could fill that gap in duration without LDES” and suggested that a combination of short-duration BESS and “clean” gas could be a more efficient and cheaper solution.
The lawsuit is currently ongoing and the judge is expected to outline the dispute and set a timeline for the case before the end of the month.
Zenobē supplies 300 MW/600 MWh Scottish BESS
Today, Zenobē has commenced commercial operations on its 300MW/600MWh Kilmarnock South BESS in Scotland.
The site, construction of which started in early 2024, is put into use Quantum High Energy BESS technology from Wärtsilä and is “strategically located” near several offshore wind farms. Zenobē said the Kilmarnock South BESS will provide stability services to the nearby wind projects using grid-shaping inverters, only the second such project in Britain to perform this function – the first being Zenobē’s Blackhillock BESS.
James Basden said: “Kilmarnock South is a milestone for Scotland – a world-first, subsidy-free battery that will reduce energy bills and strengthen UK energy security.
“This battery will help end the absurd waste of clean Scottish wind energy.”
Following operations on the Kilmarnock South BESS, Zenobē now has 731 MW of operational BESS capacity in the UK, with a further 568 MW/1230 MWh currently under construction.
