TL;DR

Nscale’s data centre at Loughton in Essex, which ministers held up as the UK’s biggest AI supercomputer, will not open in 2027 as planned. UK Power Networks (UKPN) has reportedly told the company that the local grid cannot deliver enough electricity until somewhere between the early and middle 2030s. Nscale says it remains “committed to the project” and is looking at generating power on site.

A longer wait than first feared

This is not the first sign of trouble. In July, reports said Nscale had been told power would not arrive in time for a 2027 opening, and that it was in talks about gas fuel cells as a stopgap. The new detail, first reported by the Morning Intelligence newsletter and picked up by the Guardian, is the scale of the delay: years rather than months.

The site wants up to 90MW, which the Guardian likens to the power use of roughly 315,000 homes. UKPN would not discuss a single project, but said many data centres connecting to its network are “awaiting works on the wider national electricity transmission network” before they can operate. National Grid said it was working with the system operator, NESO, to speed connections where it could.

Loughton has had a rocky run. In March the Guardian found the plot was still a working scaffolding yard, and local council officers objected to its energy demands. Nscale has since cleared the yard.

Why it matters

The project carries political weight. Keir Starmer’s government named it in the 2025 AI strategy as the “largest UK sovereign AI datacentre”. A flagship site stuck in the grid queue for years undercuts that promise.

It is also not an isolated case. In June, Ofgem said 315 data centres were waiting for National Grid connections, together asking for 73GW. That is well above the country’s entire peak demand of 45GW.

For Nscale, the timing is awkward. It is seeking a £26bn ($35bn) stock market listing, having filed its IPO papers this month. Its headline customer deal, Anthropic’s £33bn ($45bn) pledge to rent computing power, is tied to its West Virginia campus rather than to Britain.

Looking forward

Watch whether Nscale commits to on-site generation at Loughton, and whether its listing documents say more about the delay. For UK AI policy, the lesson is plain: announcing sovereign compute is quicker than connecting it.