UK's Largest AI Supercomputer Delayed by Lack of Grid Power
Britain's planned AI supercomputer in Loughton, Essex, billed as the country's largest, will miss its 2027 launch and may not receive enough grid electricity until the mid-2030s. The delay was reported on 24 September by The Guardian.
The project is being developed by Nscale, a British startup now seeking a $35bn (£26bn) stock market listing. The company has cleared the former scaffolding yard in Loughton. It is seeking up to 90 megawatts (MW) of power for the facility, roughly enough electricity for about 315,000 homes.
UK Power Networks, which operates the local electricity network, has reportedly told the company the grid cannot supply that amount of power until the early to mid-2030s. That warning was first reported by Morning Intelligence, an AI industry newsletter.
The Loughton scheme was a central part of the UK government's AI strategy announcement in 2025. Ministers described it then as the "largest UK sovereign AI datacentre", meaning a large computing facility under UK control. An earlier government blueprint in January 2025 said the sovereign facility was contracted to be built by 2026, according to government records. The Essex site was expected to create up to 250 permanent jobs, the BBC reported.
Nscale said it was "committed to the project" and is investigating generating power on site and options to speed up the grid connection. The company has not secured an alternative date for getting power.
Pressure on the grid goes beyond Loughton. You can think of the connection queue like a long line for a limited number of sockets. Ofgem said 315 datacentres were waiting to connect to the National Grid, with combined demand of 73 gigawatts (GW) compared with peak national demand of 45GW. New datacentre capacity delivered in Europe, the Middle East and Africa since January was down 11% on the same period a year earlier, with lack of available power delaying timelines, Reuters reported in November 2025. In the United States, AI expansion plans were likely to be slowed by severe power-infrastructure bottlenecks including turbine shortages and slow grid expansion, Reuters reported in February 2026.
Loughton has already seen shifting timelines. The Guardian reported in March 2026 that the system was set to come online later that year, after Nscale raised $2bn and added Sheryl Sandberg and Nick Clegg to its board. That reporting followed earlier Guardian examinations of the site as a scaffolding yard and of speculative datacentre development nationally. The Loughton project has separately been valued at £2bn.
The broader context here is a clash between plans for UK-controlled AI computing and the physical limits of the power queue. For policymakers, the test is whether AI growth zones and grid reform can bring an early-2030s connection offer forward to a workable date. For operators and investors, building on-site power trades grid delay for higher upfront costs, emissions permits and fuel supply questions. It also shifts attention for a listing of this size to secured electricity, not headline power figures or chip orders.
Looking at what this means for buyers, businesses hoping to use British computing capacity should weigh promised build dates against the actual power offer from the local network operator and place in the queue. A site cleared and ready for equipment is not the same as a site ready for electricity. Until UK Power Networks, Ofgem and developers align on firm capacity, limits on supply and temporary power, Loughton will function less as near-term supply and more as a guide to how quickly the UK can turn AI plans into working machines.
