I don't think a single 100-word email using GPT-4 alone can cost 140wh, even considering how expensive GPT-4 is to run. If it takes 20 seconds for the model to

I don't think a single 100-word email using GPT-4 alone can cost 140wh, even considering how expensive GPT-4 is to run. If it takes 20 seconds for the model to compose the letter, that means: (3600/20)*140=25200W, a 25200W piece of hardware is used just to compose your email and no other request, this seems wrong by several orders of magnitude.