About 0.3 Wh for a short text query. The long-standing estimate of 2-3 Wh (10 times a Google search) has been divided by about 10 by recent analyses: Google measured a median Gemini query at ~0.24 Wh, and Sam Altman puts ChatGPT at ~0.34 Wh. An AI query and a Google search are now of the same order of magnitude.
Read the source article: ChatGPT carbon footprint: what it means for your company