Are data centres powered by coal, gas or renewables?
Mostly fossil fuels. By the IEA’s estimate (Energy and AI, 2025), the electricity data centres use worldwide comes about 30% from coal, 26% from gas, 27% from renewables (mainly wind, solar and hydro) and 15% from nuclear. It’s shaped by where data centres are: the US used 45% of the total and China 25%. That’s the grid they draw from, not what companies buy on paper, which is why “fully renewable” claims can differ.
The bigger pictureLooking ahead, the IEA expects renewables to meet about half of the growth in data-centre demand.
What nobody knows yet
- The IEA page doesn’t give the exact year for this split.
- No industry-wide figure exists for renewables bought through contracts.
Sources (7)
- IEA, Energy and AI (2025) Estimated
“Coal, with a share of about 30%, is the largest source of electricity”
Quote checked on the page, 18 Oct 2026 - IEA, Energy and AI (2025) Estimated
“Natural gas is the third-largest source today, meeting 26% of the demand”
Quote checked on the page, 18 Oct 2026 - IEA, Energy and AI (2025) Estimated
“Renewables – primarily wind, solar PV and hydro – currently supply about 27%”
Quote checked on the page, 18 Oct 2026 - IEA, Energy and AI (2025) Estimated
“followed by nuclear with 15%”
Quote checked on the page, 18 Oct 2026 - IEA, Energy and AI (2025) Estimated
“The United States accounted for the largest share of global data centre electricity consumption in 2024 (45%)”
Quote checked on the page, 18 Oct 2026 - IEA, Energy and AI (2025) Estimated
“followed by China (25%) and Europe (15%)”
Quote checked on the page, 18 Oct 2026 - IEA, Energy and AI (2025) Forecast
“Half of the global growth in data centre demand is met by renewables”
Quote checked on the page, 18 Oct 2026
Cite this
IEA, Energy and AI (2025), as quoted in Hum, “Are data centres powered by coal, gas or renewables?”, https://humearth.org/q/power-mix (quote checked 18 Oct 2026).
Cite the original source first; Hum is where you found it.
What do Wh, kWh and TWh mean?
Wh is a watt-hour: a 1-watt light left on for an hour. 1 kWh = 1,000 Wh, and 1 TWh = 1 billion kWh. Hum compares each number with something everyday so you don’t need the units.
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The world’s data centres run mostly on fossil fuels: about 30% coal and 26% gas, with 27% renewables and 15% nuclear (IEA, Energy and AI 2025).