How much energy does agentic AI actually use? One scientist tracked every prompt he sent

As a climate scientist, Zeke Hausfather uses artificial intelligence every day for research and data analysis. But he kept wondering how much energy all that AI use was consuming. So over eight weeks this summer, he tracked the 1,138 prompts he typed into Claude Code and estimated how much electricity they consumed at data centers. Tech companies have shared little data about the energy use of their AI models. One of the few public estimates comes from Google, which said last year that a typical text prompt on Gemini used just 0.24 watt-hours, less than watching TV for nine seconds. OpenAI’s CEO, Sam Altman, has said a ChatGPT query uses a similar amount, around 0.34 watt-hours. But Hausfather suspected those figures no longer reflected how people are actually using AI. “In the AI world, a year is an eternity,” Hausfather says. A year ago, most AI use was still simple conversations in chatbots. Now, agentic AI is increasingly dominant, “where you give a set of instructions to an agent to go spin up 20 different subagents, and do some massive process that is taking orders of magnitude more energy use,” he says. “I thought it would be interesting to use the actual history of my agen…