Energy and AI

This claim about water use has been republished in dozens of other outlets. It is probably the most influential single statistic when talking about AI’s impact on the environment. Anyone who believes it is true will be trying to solve a problem that doesn’t exist.

The article, compellingly, centers on the morality of the customer’s actions. You, the end user, are held responsible for consuming half a liter of water every time you use an LLM. If this were true, you could, clearly, have a meaningful impact by boycotting ChatGPT. It would also be important to try to prevent other people from using ChatGPT, since they are directly responsible for using up a lot of water.

The takeaway is that it’s impossible to know with any certainty, because companies don’t disclose what they’re building.

I think a lot of people don’t realize how much water we each use every day. Almost all electricity generation involves heating water to create steam to spin a turbine.

When I hear people say “50 ChatGPT searches use a whole bottle of water!” I think they’re internally comparing this to the few times a year they buy a bottle of water. That makes ChatGPT’s water use seem like a lot. They’re not comparing it to the 1200 bottles of water they use every single day in their ordinary lives.

Each ChatGPT prompt uses between 10-25 mL of water if you include the water cost of training, the water cost of generating the electricity used, and the water used by the data center to cool the equipment. This means that every single day, the average American uses enough water for 24,000-61,000 ChatGPT prompts.

ChatGPT and other AI chatbots are extremely, extremely small parts of AI’s energy demand. Even if everyone stopped using all AI chatbots, AI’s energy demand wouldn’t change in a noticeable way at all. The data implies that at most all chatbots are only using 1-3% of the energy used on AI.

I have a similar reaction to the 10x a Google search point. When someone says “ChatGPT uses 10x as much energy as a Google search” I’m sometimes tempted to just say “Yes… 10 Google searches.” and just let that hang. Imagine going back to 2020 and saying “Oh man, I thought my buddy cared about the climate, but I just found out he… oh man I can’t bring myself to say it… he searched Google TEN times today.”