A decade ago data centre demand was a rounding error in most grid forecasts. In several regions it is now the fastest-growing category, concentrated in a few locations.

That concentration is the difficulty. A single campus can request as much power as a mid-sized town, and connection queues stretch for years.

Operators have started signing long-term contracts for firm generation, effectively financing capacity that would not otherwise be built.

Regulators are catching up, with proposals ranging from location-based tariffs to explicit requirements that new load bring its own supply.