IN Brief:
- Phase 1 offers up to £3 million for development studies supporting UK electrochemical storage demonstrators.
- Eligible technologies must provide at least 100 continuous discharge hours and achieve a working life of 25 years.
- A planned second phase has at least £10 million allocated for large-scale demonstrators, with projects targeted by 2030.
Innovate UK has opened a £3 million competition for development studies intended to move electrochemical ultra-long-duration energy storage technologies towards UK grid-connected demonstration.
The programme requires proposed systems to provide at least 100 continuous hours of discharge and achieve a working life of at least 25 years. It is the first phase of a planned two-stage process aimed at establishing at least two UK demonstrator projects by 2030.
Applications opened on 3 August and close at 11am on 30 September 2026. Individual projects must request between £350,000 and £700,000 of eligible grant funding, with awards supporting technology assessment, engineering design, cost and scale-up planning, market analysis, project development, manufacturing, and supply-chain work.
At least £10 million has been allocated to a second phase expected to launch in mid-2027. That later competition is intended to support large-scale demonstrators, although participation in the first phase will not guarantee funding or automatic eligibility.
Two pathways target different maturity levels
The competition divides eligible technologies into two streams, recognising that ultra-long-duration electrochemical systems range from near-commercial equipment to concepts intended to compete with strategic gas-fired reserve.
Stream 1 is designed for near-commercial scale-up. Projects must feature technologies capable of storing electricity for several days and supporting intraday or interday arbitrage, uninterruptible power, and backup during extended outages. Applications must plan for a grid-connected demonstrator of at least 100MWh by 2030.
These projects must envisage total ownership costs below $40/kWh by 2030 or provide evidence that the technology could compete with installed lithium iron phosphate systems. Applicants also need a commercialisation plan and a credible route to UK manufacturing and domestic supply-chain development.
Stream 2 is aimed at earlier-stage system innovation and lower-cost pathways. The technologies must have the potential to provide monthly or seasonal arbitrage with limited degradation or self-discharge, performing a role comparable to the strategic reserve currently supplied by unabated combined-cycle gas turbines.
Stream 2 projects must plan a grid-connected pilot of at least 100kWh by 2030 and target total ownership costs below $15/kWh during the early 2030s, or otherwise demonstrate a route to competing with gas-fired generation.
The different demonstrator scales reflect the maturity gap between the two routes. A 100MWh project requires equipment approaching commercial deployment, while a 100kWh pilot can test an earlier chemistry, cell architecture, electrolyte, or system concept before committing to utility-scale manufacturing.
Both streams face the same central problem: extending storage duration without allowing equipment and material costs to rise in proportion to every additional hour. Conventional battery systems can add energy by installing more cells, but that approach becomes increasingly expensive where discharge must continue for days rather than hours.
Development work must confront delivery risk
Innovate UK is requiring more than laboratory performance data. Each study must examine engineering design, scale-up costs, market positioning, site development, manufacturing, and supply chains, creating an evidence base for projects that could progress into construction.
Grid connection will be a significant part of that work. Demonstrators need import and export arrangements appropriate to their power rating, operating profile, and network location. Developers must establish how the system will charge, what services it will provide, and whether the chosen site can support prolonged operation without creating a new constraint.
Planning, environmental assessment, land, safety, and community engagement will also influence deliverability. Novel electrochemical systems may use unfamiliar materials, storage vessels, pumps, thermal-management arrangements, or balance-of-plant equipment requiring project-specific risk assessment and consenting.
Manufacturing plans must show how prototypes can become repeatable products. That includes material availability, supplier qualification, production equipment, quality assurance, testing, transport, installation, maintenance, and end-of-life management.
The programme forms part of UKRI’s Clean Energy Superpower Mission, which has at least £500 million of support through to 2030. The Faraday Institution is acting as technical adviser and delivery partner for the storage challenge.
Modelling cited in the competition material suggests that ultra-long-duration electrochemical storage may need installed costs around $15/kWh and annual returns above 6% to compete with gas-fired reserve. The documentation estimates a UK opportunity of up to 3TWh a year and potential system-balancing savings exceeding £1 billion annually if those conditions can be achieved.
Those figures describe the scale of the opportunity rather than the maturity of the present market. Innovate UK acknowledges that electrochemical technologies in the greater-than-100-hour range are not yet sufficiently mature or cost competitive with gas, with some approaches remaining conceptual.
The challenge is targeting at least two demonstrators by 2030 and deployment at gigawatt-hour scale by 2035. Achieving that timetable would require studies to move quickly into site selection, engineering, consent, procurement, manufacturing, and financing.
The first-phase grants cannot resolve every issue, but they can expose weaknesses before far larger sums are committed. A technology may satisfy a laboratory-duration target while failing on material availability, pumping losses, construction cost, safety, maintenance, or route to market.
Ultra-long-duration storage has no shortage of ambitious chemistry claims. The competition is structured to identify which ones can survive contact with a grid connection, a construction programme, and a commercially credible balance sheet.