The UK's planned largest AI supercomputer in Loughton, Essex, has been delayed from its 2027 launch date and now faces a potential postponement into the mid-2030s due to insufficient power supply capacity. The project, built by startup Nscale and highlighted by the government as central to its AI strategy, exemplifies how energy constraints have become a critical bottleneck for UK datacentre development.

UK Power Networks has informed Nscale that the local grid cannot supply the required power until the early-to-mid-2030s, a delay first reported by the AI industry newsletter Morning Intelligence. The datacentre requires up to 90MW of capacity—equivalent to powering approximately 315,000 homes. This delay reflects a broader national challenge: 315 datacentres are queuing to connect to the National Grid, collectively requesting 73GW of power, which exceeds the UK's entire peak energy demand of 45GW. Nscale is investigating on-site power generation and faster connection processes, whilst the site itself has now been cleared from its original status as an operational scaffolding yard.