As other's have said, arguing with disputable estimate isn't great. It's even worse if you don't understand physical units and miscalculate. Assuming the assumed 2Wh per prompt are correct, the calculation "2Wh * 20mio users * 24h" for a daily consumption makes no sense, since multiplying Watt-hours with time does not work. If we assume that each user generates one prompt per day, the actual (still very disputable) calculation would be 2Wh * 20mio users = 40mio Wh usage per day, which would be - according to the author's comparison - around 1000 households per day. Which isn't a lot.

I believe that energy consumption with AI is a large problem, but articles like this unfortunately do not provide a basis for arguments.