We could be really cheeky & use "energy" ratings, not power, so same as above but using joules (J): mJ, J, kJ, MJ
or the alternative energy rating used for batteries, watt-hours (Wh) with the same prefices
. The good thing is they go up or down the scale just about as far as you want to take it - I forget them all, but there's levels below "nano-" and above "mega" there's "giga", "tera" etc. calories is another one.
(In a sense, joules (energy) makes more sense than watts (power), since the latter is the
rate of energy change, while energy is a more basic unit
.)
A bit technical, but useful & very concise? What do you think? Tongue in cheek enough?
Stuart.