#2 of 30 · AI lab + cloud
Google (Gemini)
The most detailed per-prompt disclosure — attached to the fastest-growing footprint.
In plain words
How scores workGoogle scores 71 out of 100 — leader. Discloses real numbers and runs mostly on clean power. Still has a footprint, but you can see it. Confidence in this score is high confidence (A).
What helps
- Efficiency · Median Gemini Apps text prompt measured at 0.24 Wh, 0.03 gCO₂e and 0.26 mL water using a comprehensive method that includes idle capacity and overhead (May 2025 data).
- Efficiency · Energy per median prompt fell 33× and carbon 44× over the twelve months to May 2025.
- Carbon · 100% annual renewable matching for nine consecutive years and a 24/7 carbon-free energy goal for 2030; 12 GW of clean-energy contracts signed in 2025.
What hurts
- Efficiency · Figures are self-reported and not independently verified; critics note the water figure excludes water consumed to generate electricity.
- Carbon · Total emissions rose 18% in 2025, the largest annual increase Google has reported; electricity use rose 37% to about 43 TWh.
- Carbon · Total emissions were 51% above 2019 levels in 2024 (ambition-based boundary); Scope 3 is roughly four fifths of the footprint and rose 25% in 2025 on chip and server manufacturing.
What nobody knows
- Training emissions in model cards
- Third-party verified AI figures
Google is the only hyperscaler to publish a measured, fleet-wide per-prompt footprint for its assistant: 0.24 Wh, 0.03 gCO₂e and 0.26 mL of water for the median Gemini Apps text prompt. The same company used 43 TWh of electricity in 2025 (up 37% in a year), saw total emissions rise 18%, and consumed 10.9 billion gallons of freshwater. It owns about a quarter of the world's AI compute, mostly on its own TPUs.
Key figures
Per-prompt and fleet metrics. Hover a title for what it means; open “How we got this number” for the working.
Comprehensive method; 0.10 Wh under the narrower active-chip method.
On-site cooling water only (WUE-derived).
Market-based; uses Google's contracted clean energy.
Rose a further 18% in 2025.
+51% vs 2019 as of 2024.
Category-2 WUE from the inference paper; the environmental report does not print a fleet figure.
Held roughly flat in 2025 despite a 37% rise in electricity use.
Hardware & materials
The chips, power, copper and future e-waste behind the fleet — the part sustainability reports leave out
GPUs, TPUs or custom accelerators the company runs. Analyst figures are in H100-equivalents, company figures in physical chips.
How we got this number
About 4 million of these are Google's own TPUs; roughly a quarter of all AI compute on Earth.
Megawatts the AI fleet pulls. One megawatt runs roughly 750 US homes.
How we got this number
43 TWh a year ÷ 8,760 hours. Average draw implied by annual electricity; peak capacity is higher.
Terawatt-hours per year. One TWh is a year of electricity for about 95,000 US homes.
How we got this number
Up 37% in a year; roughly 3.5× 2019.
CO₂e emitted making the chips and servers before they answer a single prompt.
How we got this number
5,100,000 accelerators × 514 kg CO₂e each (chip plus share of the host server). Emitted in manufacturing, before the first prompt is served.
Tonnes of server hardware that will be retired in three to five years.
How we got this number
5,100,000 accelerators × 17 kg of server hardware each. Tomorrow's e-waste unless reused; generative AI could produce 2.5 Mt of it a year by 2030.
Tonnes of copper in cabling, busbars and transformers.
How we got this number
4,909 MW × 27 t of copper per MW (cabling, busbars, transformers).
Diesel backup units or gas turbines at the data centres, permitted or observed.
How we got this number
4,909 MW ÷ 2.6 MW per generator, the average size permitted at US data centres. Permit counts are not published fleet-wide; this is the number a fleet this size normally carries.
Share of retired servers and parts given a second life.
How we got this number
Count, not a share — Google does not publish a fleet-wide reuse rate.
Kilograms of antimony-equivalent, the life-cycle unit for scarce minerals consumed.
Score breakdown
Each pillar is 0–100; weights are fixed across the index
- Median Gemini Apps text prompt measured at 0.24 Wh, 0.03 gCO₂e and 0.26 mL water using a comprehensive method that includes idle capacity and overhead (May 2025 data). Google (arXiv 2508.15734)Google Cloud blog
- Energy per median prompt fell 33× and carbon 44× over the twelve months to May 2025. Google (arXiv 2508.15734)
- Figures are self-reported and not independently verified; critics note the water figure excludes water consumed to generate electricity. The Verge
- Total emissions rose 18% in 2025, the largest annual increase Google has reported; electricity use rose 37% to about 43 TWh. AxiosGoogle
- Total emissions were 51% above 2019 levels in 2024 (ambition-based boundary); Scope 3 is roughly four fifths of the footprint and rose 25% in 2025 on chip and server manufacturing. GoogleTrellis
- 100% annual renewable matching for nine consecutive years and a 24/7 carbon-free energy goal for 2030; 12 GW of clean-energy contracts signed in 2025. Axios
- Freshwater consumption rose 34% to 10.9 billion gallons in 2025, more than double 2021. Axios
- Fleet WUE of 1.15 L/kWh (consumptive, 2023–2024) — several times AWS and Microsoft, because many Google sites use evaporative cooling. Google (arXiv 2508.15734)
- Replenishment reached 64% of freshwater consumption in 2024 and roughly 78% in 2025, toward a 120% target for 2030. GoogleAxios
- In The Dalles, Oregon, Google's data centres used 355 million gallons in 2021 — about 29% of the city's water — figures the city fought for 13 months to keep secret. Data Center DynamicsReporters Committee for Freedom of the Press
- Per-prompt energy, carbon and water published with methodology; annual environmental report with location- and market-based Scope 2, fleet WUE and electricity. Google (arXiv 2508.15734)Google
- Reports 8.8 million components harvested from retired servers for reuse or resale in 2024. Google
- No training-emissions disclosure for Gemini models and no third-party verification of the inference study. The Verge
- Net-zero across operations and value chain by 2030, 24/7 carbon-free energy on every grid by 2030, 120% water replenishment by 2030. Google
- Funded The Dalles' legal fight to withhold water records from The Oregonian before reversing course and paying the newspaper's costs. Reporters Committee for Freedom of the Press
- Now backing public water-reporting standards for data centres amid local backlash. Axios
Models
What this company ships, and what each prompt costs
| Model | Weights | Energy / prompt | Water | Training CO₂e |
|---|---|---|---|---|
| Gemini (Apps, median text prompt) Frontier (undisclosed) | Closed | 0.24 Wh DisclosedCompany figure. Published by the company itself. We take it as given and record the scope next to it. | 0.260 mL DisclosedCompany figure. Published by the company itself. We take it as given and record the scope next to it. | 9,000 t Estimateecogpt.co estimate. Our own estimate from published factors. The working is shown next to the number; treat it as an order of magnitude, not a measurement. |
Where the compute lives
Named sites from company disclosures and press reporting
- The DallesOregon, USA · ~29% of the city's water in 2021.
- Council BluffsIowa, USA
- MesaArizona, USA · 86% clean electricity per Google.
- HaminaFinland · Seawater cooling; among the highest CFE regions.
- St. GhislainBelgium
- Changhua CountyTaiwan
Timeline
Incidents and developments involving this company
Google reports its largest-ever emissions jump: +18% in 2025
Electricity use rose 37% in a single year, total emissions 18%, and freshwater consumption 34% to 10.9 billion gallons — even as operational emissions fell 2% and 12 GW of clean-energy deals were signed.
GoogleGoogle publishes a measured per-prompt footprint for Gemini
0.24 Wh, 0.03 gCO₂e and 0.26 mL of water for the median text prompt, measured fleet-wide with idle capacity included. Critics say the water figure leaves out electricity-generation water.
GoogleThe Dalles fought 13 months to hide how much water Google uses — 29% of the city's supply
After The Oregonian requested Google's water records, the city sued the newspaper, with Google funding the fight. Records released in the settlement show 355 million gallons in 2021, nearly triple 2017.
Google