AINEWS
Britain's energy regulator says 73GW of datacentre demand, more than the country's peak, is sitting in the queue. The refundable deposit is designed to flush out speculators holding grid slots without committing to build, not punish real builders.
Britain's grid-connection queue now holds 73GW of datacentre demand, roughly 30GW more than the country has ever pulled at national peak. Ofgem, the regulator that runs that queue, has a proposed answer that is not a tax. It is a test: every 500MW of reserved capacity comes with a £350m pledge (about $445m at recent exchange rates), refunded only when the project actually powers up.
The mechanic matters more than the headline number. Ofgem's queue is not a list of datacentres under construction. It is a list of reservation holders, drawn from a much smaller pool of real builders, and it has been growing faster than Ofgem's own staff expected. In a February 2026 call-for-input the regulator logged 140 proposed datacentres at 50GW. Six months later, Guardian reporting on the consultation puts the count at 315 projects totalling 73GW. Each of those projects is sitting in front of housing developers, electrified rail schemes, and battery plants that also need a hookup.
The consultation Ofgem opened after the announcement is built around a screening filter. Projects would post security in the form of a letter of credit, a bond, or a cash deposit when a connection offer is made, and would lose access to the queue if they miss milestones like securing customers or financial backing. Ofgem's framing is explicit: it wants capacity reserved for projects "most likely to be built, not projects preserving options". Translation: option-preservers, the operators who locked in a slot years ago and are now waiting to see if AI demand justifies building, are the target. Builders with signed tenants and balance sheets are not.
The mechanic mirrors a parallel cleanup already underway. Neso, the system operator that runs the live grid, spent 2025 clearing "zombie" renewable projects from its supply-side queue, the speculative wind and solar schemes that held connection agreements without breaking ground. Ofgem's deposit is the demand-side version of the same logic. A reservation on a constrained network has been a free option on someone else's balance sheet; the deposit converts it into something the holder has to defend.
£350m per 500MW is a large enough hurdle that a thin project cannot quietly roll it forward, and small enough that a real hyperscaler can write the check without flinching. Ofgem's preferred direction treats the security as recoverable on energisation, so the cost is closer to a multi-year interest charge than a permanent tax. Whether the screen clears option-preservers or simply pushes them to refinance depends on milestones the consultation has not yet defined, and on which projects actually post the bonds.
Amazon and Microsoft appear in the Guardian's reporting as queue participants; neither company has publicly attributed specific UK projects to those reservations. If the deposit forces disclosure, the consultation will surface who is actually serious. If the screen is loose, the queue keeps its current shape and grid capacity stays rationed.
Two things to watch in the consultation. First, the milestone definitions: tight enough to evict speculators, loose enough not to punish projects waiting on planning or grid reinforcement. Second, whether Neso's renewable-queue reform gets folded in, so the demand-side deposit and the supply-side cleanup are run as one rationing system rather than two. Ofgem's preferred direction is on the table. The filter is what the next few months will define.