I guess it depends on what you mean by "everybody would understand". Most people I know would get glazed eyes if I used terms like those. How many people really have context for understanding what those terms mean? Most people can understand what meter is since there are so many items laying around that are approximately 1 meter long.

You conveniently ignored part "without ambiguity".

I don't think it is much to expect that one would be able to connect a electricity bill where one pays for monthly energy usage stated in kwh to article where energy is also stated in kwh.

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.

I work in the energy metering industry, but 12,000 homes over 3 seconds is still a more meaningful measurement of power for me than 72 kWh (or whatever the value they were trying to capture was). It really is a lot of power to send in 3 seconds.

I am European and I don't have a clue how much energy US home uses. Is it one in Alaska, Hawaii or maybe New Jersey?

Let alone: Is it a sprawling mansion or a one person apartment?