The simulations
1.3 g CO₂eunder 1% of the emissions
20 Wh · 22 mL · 127 AI calls
The AI colleagues' replies in the sessions, speech in and out, and the notes after the session. The conversations go to Mistral AI on the EU endpoint.
Every time an AI colleague replies, a data centre uses electricity and water. Here we show how much we estimate our AI use has cost so far — in the simulations, in the tool and in building it — and how we calculate it.
About the same as driving 2,080 km in an electric car, or emitting as much as 1,150 km in a new petrol car.
The figures are estimates with a range, not measurements: none of the AI providers we use state how much electricity their models need. We therefore show a medium estimate, with the low and high estimates beside it.
Calculated 5 Oct 2026, 16:29. The figures are updated every six hours.
We divide the AI use into three: what students meet in the sessions, the tool educators use, and the work of building it all.
1.3 g CO₂eunder 1% of the emissions
20 Wh · 22 mL · 127 AI calls
The AI colleagues' replies in the sessions, speech in and out, and the notes after the session. The conversations go to Mistral AI on the EU endpoint.
8.2 g CO₂eunder 1% of the emissions
22 Wh · 25 mL · 12 AI calls
The builder assistant, the help chat, the preview and the AI test. Here we mostly use Claude from Anthropic, which runs in the USA.
139 kg CO₂eover 99% of the emissions
374 kWh · 412 L · 32,866 AI calls
When we build and fix the tool with the AI assistant Claude Code. This is the largest item, and it does not depend on how many students use the tool.
Counted from September 2026.
Most of the footprint comes from development, not from the students. Building a tool with AI uses far more than running it — and we would rather show that figure than hide it.
Before 2 October 2026 we stored usage only for the conversations in the sessions and for the AI test. The other usage by the tool before that date is missing from the figures.
A worked example: 30 students in a written session of 45 minutes. We use typical figures for how much the students write and how long the replies are.
Some figures that have shaped our choices. Each point refers to the sources at the bottom of the page.
Counting the whole life cycle of the power stations, electricity production in 2025 emitted about 28 grams of CO₂e per kWh in Norway, 41 in France, 210 on average in the EU and 384 in the USA. The same AI reply can therefore have many times the emissions, depending only on where the data centre is. Counting only the emissions from the power stations themselves, France was as low as 19.6 grams.1,2
The AI colleagues reply using Mistral AI, a French company, which stores and processes data in the EU by default. The website itself runs at Upsun in OVHcloud's data centre in Gravelines in northern France, which Upsun puts at 58 grams of CO₂e per kWh.5,6
Google measured that a typical text request to Gemini used 0.24 Wh in May 2025, and Epoch AI estimates about 0.3 Wh for an ordinary ChatGPT reply. That is like a 10-watt LED bulb for a minute and a half to two minutes. Anthropic, which makes Claude, does not publish such figures, so we have to use other companies' figures as a reference.7,8
Mistral AI had a life-cycle analysis made of its Large 2 language model together with Carbone 4 and the French environment agency ADEME. With training and the production of hardware included, a 400-token reply came to 1.14 grams of CO₂e and 45 millilitres of water. The training and the first 18 months in use together came to 20,400 tonnes of CO₂e and 281,000 cubic metres of water. We use the method as an upper bound under “How we calculate”.9
Data centres use water for cooling. Google states 0.26 millilitres per Gemini request — about five drops. Researchers at the University of California estimated that GPT-3 used half a litre for 10–50 replies when the water used in power generation is included. The difference shows how much it matters what is counted.7,10
Researchers from Hugging Face and Carnegie Mellon measured open models and found that generating an image used on average more than 60 times as much electricity as generating a text reply. That is why we count the images in “Create your avatar” separately.11
Data centres used about 415 TWh of electricity worldwide in 2024, around 1.5 per cent of all electricity use, and the International Energy Agency expects the figure to roughly double by 2030. In the USA, 4.4 per cent of all electricity went to data centres as early as 2023.12,13
From 27 September 2026, the EU prohibits claiming that a service is climate neutral because its emissions are offset with purchased credits. Norway has adopted the same rule, but it has not yet entered into force. The Norwegian Consumer Authority already advises against such claims. We therefore state what we do, and how much — not that the footprint is gone.14,15,16
Four steps from each AI call to the figures at the top. The factors below are the same ones the calculation uses, so they can never say anything different from the figures.
Each AI call stores how many tokens (pieces of text) went in and out, which model replied and which provider ran it.
Tokens are multiplied by an estimate of electricity per 1,000 tokens, depending on the size of the model. Input tokens count for less than output tokens, and reused tokens for almost nothing.
The electricity is multiplied by the emissions per kWh of the electricity grid where the provider runs the model — not by purchased guarantees of origin. If the provider does not state the country, we choose a range that covers the countries concerned.
The electricity is multiplied by how much water data centres on average use for cooling per kWh. Water used in the power stations is not included.
| Model size | Low | Medium | High |
|---|---|---|---|
| SmallMistral Small, Claude Haiku | 0.05 Wh | 0.15 Wh | 0.5 Wh |
| MediumMistral Large and Medium, Claude Sonnet | 0.15 Wh | 0.5 Wh | 1.5 Wh |
| LargeClaude Opus and Fable | 0.3 Wh | 1.2 Wh | 3 Wh |
| Provider | Low | Medium | High |
|---|---|---|---|
| Mistral AIEU (Mistral does not state the country) | 15 g | 35 g | 175 g |
| Speechmatics (speech in)EU | 20 g | 175 g | 250 g |
| Anthropic (Claude)USA | 250 g | 370 g | 450 g |
| ElevenLabs (speech out)Unknown, USA or EU | 20 g | 250 g | 450 g |
| Google (images)USA and global | 125 g | 370 g | 450 g |
Emissions per kWh for the same country can vary a lot, depending on what is counted. We therefore show a range and explain how we have chosen.
Cooling water: 1.1 litres per kWh (range 0.2–1.8).7
Upper ceiling by Mistral AI's life-cycle method, with training and hardware: 187 kg CO₂e. It is not added to the figures at the top, but shows how high the footprint can get when everything is counted.9
We have not offset the footprint yet. When we do, it will be stated here: what we have bought, from whom, for how many tonnes, and when.
Our highest estimate so far is 426 kg CO₂e (the high electricity estimate or the life-cycle ceiling, whichever is larger). This is what it would cost to offset it:
| Type | Price per tonne | For us now |
|---|---|---|
| Forest and nature credits (not permanent) | 7–24 € | NOK 32–NOK 110 |
| EU allowances that are cancelled | 80–86 € | NOK 367–NOK 395 |
| Nature-based removal | 30–150 € | NOK 138–NOK 688 |
| Biochar (permanent removal) | 105–200 € | NOK 482–NOK 918 |
Prices read on 3 October 2026 from the providers' own websites and S&P Global (EU allowances).
The type tells you how far you can trust the figure: research is peer reviewed, while companies' own figures have not been checked by anyone outside.
Last updated 5 October 2026. The factors are checked at least every six months, and whenever a provider publishes its own figures.
Do you see an error, or have a better source? Write to kontakt@virtualaicorp.no.