I think it is too much. I pay my hydrobill and I still have no idea how to visualize a hwh. However saying 12000 homes for 3 seconds makes sense for me. It is roughly the same power that a large neighbourhood would use.

Also, what does the ambiguity matter in this situation? This isn't a technical paper.

I'd wager few people look at the kilowatt hours on their electric bill. They look at the dollars. I know that my monthly electric bill is about $100. I would have no idea how many kilowatt hours without looking.

Hah! I've never looked at the amount of kwh I've used on my bill. All that matters is the amount of money I owe.