Britain’s datacenter hubs face a reckoning. AI workloads demand vast electricity, yet London’s grid strains under the weight. Over 80% of the UK’s capacity clusters in Greater London and surrounds—more than 200 facilities in Slough, Redhill, Hayes, and near Heathrow. But saturation hits. Land scarce. Power contested with homes and factories. Operators pivot. AI doesn’t always need split-second links to the City anymore. Mark Lewis, Pulsant chief marketing officer, puts it bluntly: “A lot of organizations still default to London in early planning, then run into delivery friction. AI has made the power question impossible to defer. The smart move is to start with the workload, the latency tolerance and the power profile, then choose the geography that can deliver on those constraints.” The Register reports this shift clearly. West London chokes first. Slough Trading Estate packs up to 35 datacenters. Heathrow hums nearby. Grid limits bite harder as AI racks pull megawatts. UK electricity costs four times U.S.…