Does big tech really run on 100% renewable energy?
The claim: “Big tech runs on 100% renewable energy.”
Partly. The 100% is a yearly sum on paper: companies buy clean power or certificates equal to the electricity they use. Google says it matched 100% of its 2025 consumption this way. Counted hour by hour on each local grid, its data centres and offices ran on about 65% carbon-free energy. Google itself says firms with a 100% annual match still use fossil power when or where clean power isn’t available. Counted on the grids it drew from, its electricity emissions were about 5.4 times what it reports after purchases.
The bigger pictureWorldwide, the grids data centres draw from supply about 30% of their electricity from coal and 26% from gas, with about 27% from renewables, by the IEA’s estimate. A peer-reviewed Princeton study of the western US grid found that matching a year’s use has minimal impact on long-run emissions, while matching it hour by hour can cut them significantly.
- 100 % Matched with renewable purchases: added up over the year, worldwide (company figure)
- 65 % Carbon-free, hour by hour: each hour, on each local grid (company figure)
Hollow dots are the companies’ own figures. Unit: % of electricity.
Why the claim misleads
The purchases are real, and the yearly sum adds up. But it isn’t the electricity the data centres draw from the grid each hour. Another study estimates that if certificate use keeps its trend, 42% of companies’ promised cuts in electricity emissions won’t be real-world cuts.
What nobody knows yet
- These are the companies’ own figures. Hum found no independent hour-by-hour measurement of their clean power.
- Google publishes an hourly figure. Many companies don’t, so their 100% claims can only be checked as a yearly sum.
- Google’s electricity demand grew 37% in 2025. It doesn’t say how much of that growth is AI.
Sources (11)
- Google, 2026 Environmental Report (its own figures) Company says so
“In 2025, we navigated our largest load growth in history—a 37% annual increase in electricity demand. Despite this, we again matched 100% of our electricity consumption with renewable energy purchases (on a global and annual basis)”
Quote checked on the page, 25 Oct 2026 - Google, 2026 Environmental Report (CFE: carbon-free energy, counted each hour on each local grid) Company says so
“In 2025, we achieved a global average of approximately 65% CFE across our data centers and offices, remaining relatively flat compared to 66% in 2024”
Quote checked on the page, 25 Oct 2026 - Google, 2026 Environmental Report Company says so
“even companies that meet a 100% annual match continue to rely on power generated by fossil fuels during times when, or in places where, carbon-free generation isn’t available”
Quote checked on the page, 25 Oct 2026 - Google, 2026 Environmental Report, emissions data table (columns 2019 to 2025; the last figure in each row is 2025) Company says so
“Scope 2 (location-based) tCO2e 5,173,000 5,845,000 6,498,700 7,963,700 9,085,700 11,067,100 15,148,700 Scope 2 (market-based) tCO2e 788,200 921,200 1,769,400 2,430,200 3,288,000 2,898,600 2,815,000”
Quote checked on the page, 25 Oct 2026 - Meta, 2025 Environmental Data Index (an EAC is an energy attribute certificate) Company says so
“We have publicly committed to matching 100% of our electricity use with clean and renewable energy including wind, solar, and hydropower. We procure and retire one EAC for every MWh of electricity used to power our global operations.”
Quote checked on the page, 25 Oct 2026 - Nature Climate Change (2022), peer-reviewed study of renewable energy certificates (RECs) used by companies with science-based targets Estimated
“If this trend continues, 42% of committed scope 2 emission reductions will not result in real-world mitigation.”
Quote checked on the page, 25 Oct 2026 - Joule (2024), peer-reviewed Princeton study modelling the western United States Estimated
“procurement strategies that match participants’ demand with carbon-free generation on an annual basis have minimal impact on long-run system-level CO2 emissions”
Quote checked on the page, 25 Oct 2026 - Joule (2024), peer-reviewed Princeton study modelling the western United States Estimated
“matching participants’ demand on an hourly basis with carbon-free generation can drive significant reductions in system-level CO2 emissions”
Quote checked on the page, 25 Oct 2026 - 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
Hum’s sums
- Google 2025: 15.1 million tonnes counted on the grids it drew from (location-based) ÷ 2.8 million tonnes after its purchases (market-based) ≈ 5.4 times
Cite this
Google, 2026 Environmental Report (its own figures), as quoted in Hum, “Does big tech really run on 100% renewable energy?”, https://humearth.org/q/renewable-claims (quote checked 25 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.
Send this answer
“100% renewable” is a yearly sum on paper. Google matched 100% of its 2025 electricity that way, but hour by hour on local grids it ran on about 65% carbon-free energy, by its own figures.