WaterLevel 1 of 6 calculation factorCalculation factor, level 1 of 6Database structure 
6Territories
5Organisations
4Occupations and activities
3Uses
2Machine operationsOn-site cooling water, per kWh
The water evaporated on site to cool the servers, for each kilowatt-hour of computing.
- Reference value, not yet applied to uses: convention C6 on water remains to be settled.
- Out of scope: the water of electricity generation, counted in the water of one kilowatt-hour, and the water of hardware manufacturing.
Sentence to citeOn-site cooling water: 1.15 L per kWh selected, from 0.3 to 1.15 L depending on the operator.
Origin of the value
The reference value of the database is 1.15 litre, Google's measurement on its centres that serve language models (2023 and 2024), the only one made on AI centres; it is the same large-operator centre as the PUE of 1.10 selected by the database. It is not yet applied to uses: convention C6 on the three waters remains to be settled. The other readings of the same scope are lower: 0.30 litre across the whole Microsoft fleet, 0.36 litre on average for US centres of all types in 2023 (Lawrence Berkeley National Laboratory).
Characteristics
| Unit | 1 kWh |
|---|---|
| Counted | the water evaporated on site by cooling, relative to the servers' electricity |
| Not counted | the water of electricity generation, counted in the water of one kilowatt-hour, and the water of hardware manufacturing |
| Status | published, 4 readings of the same scope, 2 other published values |
All the characteristics
| Identifier | IA-0004, projetcelsius.com/en/ai/database/IA-0004/ |
|---|---|
| Version | 0.4 of 12 November 2026 |
| Category | Calculation factors, the foundation of the calculation |
| Choice of the selected value | value taken as it stands from its source, without calculation |
| Sources | Google, LBNL, Microsoft, Li et al., 2023 to 2025 |
| Licence | CC BY 4.0 |
Sources of the calculation
1 publication, for this entry and those used to calculate it, with the chosen parameters.
Energy and factors
The references of the selected values and of the entries used in this calculation.
Role and limits : Google
What the publication covers. chips, host, standby machines, data centre, on-site water
What it does not cover. manufacturing, training
Reading by the database. The only production measurement published by a provider
Reference of the selected value
Scope of the figure used. Google data centres serving language models, water consumption (withdrawn minus returned), average for 2024
Limit. Measurement by the operator; the same article gives 0.26 mL per question for Gemini
Published values
6 figures for the same quantity, each in its own scope.
| Source | Date | Water | What the figure measures | Scope | Status |
|---|---|---|---|---|---|
| Microsoft ↗Sustainable by design: Next-generation datacenters consume zero water for cooling | Dec. 2024 | 0.3 L/kWh | Microsoft's global fleet, financial year ending June 2024, water consumed for cooling and humidification | same scope | published |
| Lawrence Berkeley National Laboratory ↗2024 United States Data Center Energy Usage Report | Dec. 2024 | 0.36 L/kWh | Average of US data centres up to 2023, water consumed on site | same scope | estimated |
| Li, Yang, Islam and Ren, UC Riverside ↗Making AI Less Thirsty | Apr. 2023 | 1 L/kWh to 9 L/kWh | Water evaporated on site: 1 L/kWh as an annual average at Google, 9 L/kWh for a large data centre in Arizona in summer | same scope | estimated |
| Google ↗Measuring the environmental impact of delivering AI at Google scale | August 2025 | 1.2 L/kWh | Google data centres serving language models, water consumption (withdrawn minus returned), average for 2024 | same scope | measured |
| Amazon Web Services ↗2025 Amazon Sustainability Report | 2026 | 0.12 L/kWh | Amazon Web Services data centres, 2025, water withdrawn relative to server electricity | other scope | published |
| Meta ↗2025 Environmental Data Index | Oct. 2025 | 0.19 L/kWh | Meta data centres, 2024, water withdrawn relative to server electricity | other scope | measured |
The published figures do not all count the same scope; the scope of each figure is written next to it. Why do the estimates diverge?
Methodology conventions
With their alternatives
| The three waters | On-site water, power plant water and life cycle water are never added together without saying so; the factor remains to be settled |
|---|---|
| Calculate a case without an entry | The formula, the default values and a step-by-step example |
Uses in the hub
Charts, figures, analyses and articles that cite this entry
History
Entry in version 0.4 of 12 November 2026, in the database in version 0.4
- 12 November 2026Selected value : 0.36 L/kWh becomes 1.15 L/kWh.Decision of 12 November 2026: the database paired the PUE of a large operator (1.10) with the water figure of an average US data centre (LBNL, 0.36 L/kWh); the water figure now selected is that of the same data centre type, Google's measurement of its data centres serving models (1.15 L/kWh, water consumed, relative to server electricity, 2023 and 2024). No recipe uses IA-0004: no calculated figure changes.
- 12 November 2026Description : the database selects 0.36 litre, the LBNL US average becomes the database selects 1.15 litre, Google's measurement of AI data centres, consistent with the PUE of 1.10; Microsoft (0.30) and LBNL (0.36) lower.Same decision as the selected value; the range (0.30 to 1.15 L/kWh) does not change.
- 12 November 2026Version : 0.3 becomes 0.4.The selected value changes.
- 12 November 2026Description : the database selects 1.15 litre becomes the database reference value is 1.15 litre, not yet applied to uses until convention C6 is settled.Decision of 12 November 2026: convention C6 on the three types of water remains open, and no use yet calculates its water; the value does not change.
- 2 November 2026Designation : The water of a kilowatt-hour in a data centre becomes Cooling water, per kWh of data centre.More precise designation: the object first, the specification after the comma, the quantity or period at the end; the former title remains searchable.
- 2 November 2026Designation : Cooling water, per kWh of data centre becomes On-site cooling water, per kWh.In people's own words, the object first.
- 2 November 2026Short title : Cooling water becomes On-site water.Shorter.
- 2 November 2026Calculation : awaiting its value becomes value recorded.The value is recorded.
- 2 November 2026Selected value : 0.36.LBNL 2024, average of US data centres up to 2023, water consumed on site; median of readings with the same scope.
- 2 November 2026Status : not published becomes published.Published reading; convention C6 on water remains to be settled.
- 1st November 2026Creation : version 0.1.Entry added: the water of a kilowatt-hour in a data centre, six published readings, no value selected.
- 31 October 2026Creation of the database, in its first version (0.1).
