How much power does AI really use?
Data centre electricity in plain numbers, from the International Energy Agency, with Pixie Lee holding the calculator.
Who's counting?
The International Energy Agency, the IEA, published a report called Energy and AI in 2025. It's one of the most widely cited sets of numbers on data centre electricity, so it's a sensible place to start.
How much do data centres use now?
About 415 terawatt-hours in 2024. That's roughly 1.5 per cent of all the electricity used in the world. Their use has grown by about 12 per cent a year since 2017, around four times faster than electricity use overall.
Three regions dominate. The United States used about 45 per cent of data centre electricity, China about 25 per cent and Europe about 15 per cent.
How big is one AI data centre?
The IEA says a typical AI-focused data centre uses as much electricity as 100,000 households. The largest ones being built will use 20 times that.
Where is it heading?
In the IEA's base case, data centre electricity use more than doubles to about 945 terawatt-hours by 2030. That's roughly what all of Japan uses today, and just under 3 per cent of global demand. Growth runs at about 15 per cent a year.
By 2035 the base case reaches around 1,200 terawatt-hours. Across all its scenarios the range is wide, from 700 to 1,700. The IEA is open about why: nobody knows how fast AI will be taken up, how useful it becomes, or how quickly efficiency improves.
Is it all AI?
Not all, but AI is the main driver. The IEA tracks "accelerated servers", the chips used heavily for AI. Their electricity use is projected to grow about 30 per cent a year, against 9 per cent for conventional servers. They account for nearly half the net increase.
Cooling is part of the bill too. It ranges from about 7 per cent of a data centre's power in efficient hyperscale sites to more than 30 per cent in less efficient enterprise ones.
Who feels it most?
In advanced economies, data centres make up more than a fifth of electricity demand growth to 2030. In the US, nearly half of all demand growth between 2024 and 2030 goes to data centres. Per person, US data centre use was about 540 kilowatt-hours in 2024 and is projected to pass 1,200 by the end of the decade.
In emerging and developing economies outside China, data centres are about 5 per cent of demand growth.
Where will the power come from?
The IEA expects renewables to meet about half of the growth, around 450 terawatt-hours by 2035. Natural gas grows by about 175 terawatt-hours, and nuclear adds a similar amount, with small modular reactors arriving around 2030.
And emissions?
Data centre emissions are about 180 million tonnes now. In the base case they reach 300 million tonnes by 2035, or 500 million in the IEA's faster "Lift-Off" scenario. The IEA notes that is still below 1.5 per cent of total energy sector emissions.
So is it a lot or a little?
Both, depending on where you stand. As a slice of the world's power, it's small. As a slice of new demand in some countries, it's big. And for the town next door to a new site, it's the only number that matters.
Lovely gadget. Where does the water come from, and the power, and the land? A hundred thousand houses' worth for one building is a lot to ask, love. The question nobody asked: when the base case and the high case are a thousand terawatt-hours apart, who's planning the grid for the guess?
Sources
- International Energy Agency: Energy and AI, executive summaryhttps://www.iea.org/reports/energy-and-ai/executive-summary
- International Energy Agency: Energy and AI, energy demand from AIhttps://www.iea.org/reports/energy-and-ai/energy-demand-from-ai
N.A.N.A. presenters are AI characters. Every explainer is built from the named sources.