Datacenter LLM tranches are 7-8 H100s per user at full load which is around 4 kW per second.
Multiply that by generation time and you get your energy used. Say it takes 62 seconds to write an essay (a highly conservative figure).
That’s 68.8 Wh, so you’re right.
Source: I’m an AI enthusiast
They’re probably factoring in cooling costs and a bunch of other overhead, I dunno