This question gets two confident answers, and they’re both kinda wrong. One camp says every chatbot question boils a lake. The other says a prompt uses less energy than a Google search used to. The real answer is messier than either camp.
The short version
A single prompt uses a tiny amount of electricity and water. All the prompts together, plus the huge data centers being built to answer them, add up to something real. And the costs land hardest on specific towns. Both camps are right about something. That’s my read, anyway. The numbers are still pretty messy.
The case for “it’s fine (ish)”
Google says a typical Gemini text prompt uses 0.24 watt-hours of electricity and 0.26 milliliters of water (about five drops). That’s roughly the energy of running a microwave for one second. (If you count only the AI chips, Google gets 0.10 watt-hours. The bigger number includes cooling and spare machines, which is the more honest one to use.) Sam Altman put ChatGPT’s average at 0.34 watt-hours, though he didn’t explain how he got there. Google also says the energy per prompt fell 33 times in a single year.
Worth remembering: all of those figures come from the companies themselves.
The case for “it’s a real problem”
Data centers used about 415 terawatt-hours of electricity in 2024 (around 1.5% of the world’s total), and the International Energy Agency expects that to more than double by 2030. The U.S. alone accounts for about 45% of data center electricity use. Microsoft, Google, and Amazon all reported emissions going up year over year, even with big climate goals set for 2030.
And the strain is local. The Pacific Institute found that two-thirds of U.S. Data Center projects built or planned since 2022 sit in areas already short on water. A median data center pulls about 121,000 gallons a day.
Where it’s still unsettled
People have started voting with their zoning boards. Gallup found 71% of Americans oppose an AI data center in their own area. That’s a stronger opinion than most of us have about any single prompt. For what it’s worth, the IEA estimates AI could help cut energy-related emissions by about 5% by 2035, mostly by helping grids and buildings run more efficiently. That’s a real offset, if it happens.
So your one question to a chatbot probably isn’t the problem. Whether your town should host the building that answers everybody’s questions is a real question, and I don’t think anyone has a clean answer yet.