Launch of UK’s ‘largest AI supercomputer’ delayed by power supply problems

The UK's planned "largest AI supercomputer" in Loughton, Essex, will miss its 2027 launch target due to power supply constraints. The facility could now remain offline until the early to mid-2030s, dealing a significant setback to the government's AI infrastructure ambitions.

Nscale, the UK-based startup building the datacentre, had positioned the Loughton site as a cornerstone of Britain's AI strategy when it was announced in 2025. The company is currently seeking a $35bn (£26bn) flotation this year. However, UK Power Networks (UKPN), responsible for connecting the site to the local grid, has informed Nscale that sufficient power will not be available until the early to mid-2030s.

The announcement represents yet another blow to a project already mired in complications. In March, the Guardian revealed that the planned location was still operating as a scaffolding yard at the time of the announcement—a significant gap between the government's grand positioning and ground-level reality.

Energy Bottleneck Across the Datacentre Sector

The Loughton delays highlight a systemic energy crisis affecting datacentre development across the UK. Ofgem, the energy industry regulator, revealed in June that 315 datacentres are currently queuing for electricity connections to the National Grid, representing a combined demand of 73GW—far exceeding the nation's peak energy consumption of 45GW.

The Loughton supercomputer alone requires up to 90MW of capacity, equivalent to powering approximately 315,000 homes. Such large-scale projects require coordination not only at the local distribution level but also across the National Grid's wider transmission network.

A UKPN spokesperson noted that while many datacentres connect to the company's distribution network, they are awaiting essential infrastructure work on the broader national transmission system before they can begin operation. Schemes with substantial energy demands require this wider coordination to ensure the grid can safely deliver the required power.

Next Steps and Government Context

Despite the setbacks, Nscale stated it remains "committed to the project." The scaffolding yard site has now been cleared by the company, and Nscale is exploring alternative solutions, including the possibility of generating power onsite and accelerating the grid connection process through other means.

Prime Minister Keir Starmer's government had prominently featured the Loughton datacentre in its 2025 AI strategy announcement, describing it as the "largest UK sovereign AI datacentre." Datacentres serve as the infrastructure backbone for AI applications such as large language models and chatbots. The project's delay raises questions about the UK's broader capacity to support the rapid energy demands of artificial intelligence development and deployment.