Transmission // 13
A hundred and thirty-two gigawatts
2 min
Global data centre power demand is set to rise 27% this year. The rack density number is the one that should worry you, not the total.
Worldwide data centre power demand is expected to reach roughly 132 GW in 2026, up from 104 GW in 2025 — a 27% rise in a single year, with Gartner putting consumption growth at 26% globally. AI-optimised servers are projected to account for around 31% of data centre power consumption this year.
The US curve is steeper: from 31 GW in 2025 to 41 GW in 2026 to a forecast 66 GW in 2027, at which point data centres would take 8.5% of total peak summer demand, roughly doubling from 4.1% in 2025.
The number underneath the number
Totals scale. Density does not, and density is where the engineering breaks.
A conventional rack draws 5 to 15 kW. An AI-optimised rack draws 30 kW to over 100 kW. That is not a bigger version of the same problem — it is a different thermal and electrical regime. Air cooling stops working. Busway ratings stop working. The floor loading stops working. Retrofitting an existing hall for that density is frequently more expensive than building new, which is why the buildout is greenfield and why it lands in places with cheap land and weak objections.
Grid time versus datacentre time
A hyperscale facility can be designed, permitted and energised in 18 to 30 months. A high-voltage transmission line takes seven to twelve years in most US jurisdictions, and a new generating station is on a similar clock.
That mismatch is the whole story. It is why the sector is signing nuclear PPAs for capacity that does not exist yet, buying gas turbines as a bridge, and — the quiet one — increasingly building where the interconnection queue is short rather than where the customers are.
Demand is arriving on a two-year cycle into infrastructure that plans on a ten-year one. Something has to give, and it will not be the demand.
Why this belongs on an AI blog
Because the cost of a token is downstream of the cost of a megawatt-hour, and because “just run it in the cloud” is an abstraction sitting on top of a substation somebody has to build. The abstraction is getting thinner. When it finally tears, the people who kept some capability on hardware they own will find the transition boring rather than existential.
That is the whole argument for local. Not ideology — slack.