Microsoft Nscale Loughton: Microsoft ends its deal for the UK's planned largest AI site over grid power

Microsoft has ended its agreement tied to Nscale's planned AI data center in Loughton, Essex, after the site was reportedly told it would not get a grid connection until the 2030s. The Microsoft Nscale Loughton site was meant to be the UK's largest AI supercomputer. The Telegraph first reported the withdrawal on October 18, 2026, and Reuters confirmed it, according to Tech Insider. It is a UK story with a global lesson: in the compute race, power arrives later than chips.

What was planned

When Microsoft and Nscale announced the project on October 15, 2025, Loughton was one of four sites in a program of about 200,000 Nvidia GB300 GPUs, per NeoTeo's recap. Loughton was to host about 23,000 of them, at 50 megawatts scalable to 90 megawatts, with deliveries from the first quarter of 2027. The other sites were in Texas (about 104,000 GPUs), Narvik in Norway (about 52,000) and Sines in Portugal (12,600). Those are announced plans, not confirmed deployments.

Property Week describes Loughton as part of a £2 billion development and as the UK's largest supercomputer, announced under last year's UK-US tech agreement, in which Microsoft pledged £22 billion for UK AI. National Technology adds that the site was originally due to begin operating in 2027.

What went wrong

Power. Nscale expected an electricity supply by the end of 2026. Property Week reports it may now wait until the early 2030s for a connection, pending upgrades to the National Grid transmission network. Nscale has an agreement to connect to the distribution network run by UK Power Networks (UKPN), not to the transmission network. A UKPN spokesperson said it is "awaiting works on the national transmission network which we do not own."

The accounts differ on one point worth stating. Property Week reports that a source close to the situation says the connection date agreed with Nscale has not changed, and that a formal UKPN agreement promised power by the end of 2026. The 2030s timeline comes from the Telegraph's report of what Nscale and Microsoft were told. We could not reconcile the two.

What each side says

Nscale's spokesperson said the company "remained committed to both the Loughton project and the UK," that "Our relationship with Microsoft remains strong and long term," and that "this unfortunate London-wide grid issue has no impact on our other contracts." NeoTeo reports the company said it is exploring alternative power sources for the site; the statement did not specify what those are. Nscale's other joint projects with Microsoft in Norway, Portugal and the US are unaffected, according to both companies.

Microsoft's own reason for ending the agreement has not been confirmed in the reporting we opened. The grid delay is the most plausible trigger, and the coverage describes it that way, but it is an inference and not a Microsoft statement.

The wider pattern

It is not the first UK setback this year. National Technology notes that in March the Guardian reported the Loughton site was still a scrap metal yard, and that in April OpenAI pulled out of a planned £31 billion Stargate UK data center. Property Week adds context on the queue: a Roadnight Taylor report found half of UK data center developers expect a grid connection within one to two years but often wait three to eight, and more than half named securing a grid connection as the main barrier to success.

Assad Noori of JLL put the point in two sentences in Property Week: "Power supply, again, is the constraint not capital." And: "Without power you have no compute."

Ofgem has asked United Infrastructure to lead an industry effort to create standardized electricity connection archetypes for UK data centers, which is the regulatory response in motion, though it addresses the process rather than the grid capacity.

Why it matters for the race

Chips can be ordered. Substations cannot. Our earlier piece on the grid interconnection bottleneck laid out why interconnection queues, not hardware, set the pace of new capacity, and Loughton is a named example. For a lab or a hyperscaler, a site that cannot be energized until the 2030s is not a site for a 2027 training run, however good the planning permission looks.

It also bears on Nscale's own story. The company filed for a New York Stock Exchange listing in September, with a reported target valuation of about $30 billion per Property Week (the Financial Times figure, cited by National Technology, is $35 billion). Its chief executive Josh Payne said in September that total contracted value was $103 billion. We looked at the prospectus in our Nscale S-1 piece, including how concentrated that revenue is. One lost anchor site does not undo a contracted backlog, but it is the sort of delivery risk a prospectus exists to disclose.

What we would watch

Three things. First, whether Nscale names its alternative power sources and whether on-site generation can be permitted in time. Second, whether UKPN or the national grid operator publishes a firm connection date that settles the dispute between the two accounts. Third, whether Microsoft redeploys the Loughton GPUs it had earmarked to another site, which would show where it thinks power is available.

Our take

This is a grid story more than a Microsoft story. The agreement ended; the partnership did not, and both companies say so. The honest reading is that a flagship UK AI site slipped from an end-of-2026 power date to a possible early 2030s one, that the two sides of the reporting disagree on whether the contractual date moved, and that capital was not the constraint. We would not read it as a retreat from UK AI. We would read it as the clearest recent example of power setting the schedule for compute.