https://www.economist.com/technology-quarterly/2024/01/29/da... has some actual data on use.

A recent analysis in Joule, an energy journal, suggests that at the rate they are being produced, ai servers could use about 100 terawatt-hours of electricity each year by 2027, between a quarter and a fifth of total data-centre consumption. Schneider Electric, a French firm that builds power supplies for data centres, projects that ai’s share of data-centre electricity use will jump from 8% in 2023 to 15-20% in 2028.