UsesLevel 2 of 6 machine operationMachine operation, level 2 of 6Used to calculate 1 entry, level 3Calculated with 1 entry, level 1Database structure 
6Territories
5Organisations
4Occupations and activities
3Uses
1Calculation factorsTranscribe a minute of audio
The server electricity used to transcribe a minute of speech into text with a speech recognition model. Projet Celsius estimate.
- The figure covers speech recognition on the GPU and the server.
- The electricity range goes from 0.16 Wh to 0.65 Wh, within the scope of this entry.
- CO2e is calculated from electricity and the worldwide grid; it is not a direct measurement of carbon.
- Out of scope: the summary, counted in the task, data centre cooling and server manufacturing.
Sentence to citeTranscribe a minute of audio, Projet Celsius estimate: 0.17 gCO2e per minute of audio, for 0.38 Wh of electricity, servers worldwide (458 gCO2e/kWh).
- Calculated with
- Used to calculate
Origin of the value
The computing centre of the University of Erlangen-Nuremberg measured about 1,000 kWh for 40,000 hours transcribed with Whisper, cooling included. Benchmarks publish measurements per clip of a few seconds; scaled to the minute with an assumed clip length of 8 seconds, they give 0.16 to 0.65 Wh.
Comparison with the other machine operations
Characteristics
| Unit | 1 minute of audio |
|---|---|
| Default location | world, 458 gCO2e/kWh (Ember 2025, life cycle); 11 other locations to choose from |
| Counted | speech recognition on the GPU and the server |
| Not counted | the summary, counted in the task, data centre cooling and server manufacturing |
| Status | estimated, 3 other published values |
All the characteristics
| Identifier | IA-0018, projetcelsius.com/en/ai/database/IA-0018/ |
|---|---|
| Version | 0.1 of 2 November 2026 |
| Category | Machine operations, what the server computes |
| Choice of the selected value | value taken as it stands from its source, without calculation |
| Sources | · |
| Licence | CC BY 4.0 |
Result for the chosen case
This block is made of no other: its value is read from its sources.
Entries that use it (1)
Sources of the calculation
1 publication, for this entry and those used to calculate it, with the chosen parameters.
Conversion into carbon
The source of the electricity factor of the selected location.
Worldwide: 458 gCO2e/kWh, life cycle.
Role and limits : Ember
Author. Ember, Our World in Data
What the publication covers. electricity generation over the life cycle, by country
What it does not cover. guarantees of origin
Reading by the database. The same source for all countries
Conversion of electricity into carbon: worldwide
Scope of the figure used. the production of electricity over the life cycle, including power plant construction and fuels
Limit. An average for the chosen country, not the electricity contract or the data centre of a specific service.
Published values
3 figures for the same quantity, each in its own scope.
| Source | Date | Electricity | What the figure measures | Scope | Status |
|---|---|---|---|---|---|
| Transcribe one minuteselected by the database, v0.1 | 2026 | 0.38 Wh | the range published by the source: from 0.16 Wh to 0.65 Wh | same scope | estimated |
| AI Energy Score ↗AI Energy Score, task leaderboard data | 2025 | 0.0215 Wh | Distil-Whisper large v2, same set of clips, GPU alone, one query at a time | other scope | measured |
| AI Energy Score ↗AI Energy Score, task leaderboard data | 2025 | 0.0867 Wh | Whisper large v3, an audio clip of a few seconds (LibriSpeech, Common Voice, People's Speech), GPU alone, one query at a time | other scope | measured |
| NHR@FAU, University of Erlangen-Nuremberg ↗NHR@FAU helps to make FAU's video portal more accessible | 2023 | 0.417 Wh | More than 40,000 hours of videos transcribed with Whisper medium in about 2,500 GPU hours, about 1,000 kWh cooling included, scaled to the minute | other scope | computation |
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 default location | Without other information, the servers are in the world, at the world average electricity |
|---|---|
| Electricity, location-based, on a life cycle basis | The kilowatt-hour is that of the servers' country, on a life cycle basis, from a single source for all countries |
| Two significant figures | A calculated value is rounded to two significant figures, a published value is reproduced with the precision of its source; the calculation keeps full precision |
| Calculate a case without an entry | The formula, the default values and a step-by-step example |
History
Entry in version 0.1 of 2 November 2026, in the database in version 0.4
- 2 November 2026Version 0.1 of the entry, as of the date of its current value.
- 31 October 2026Creation of the database, in its first version (0.1).
