I'd be careful trying to attribute too much realism to electrical power in KSP. I suspect their values are pretty arbitrary, but here's what I've estimated. Stock spotlights consume electric charge at 0.02 and 0.04. I assume the lights are LED (Because using a filament or fluorescent globe in space seems kinda dumb to me), and the output of both seems to be fairly close to what I would expect from good quality 10W outdoor spot/flood lights (one configured for a more focused beam, one for a broad beam). One uses twice as much power as the other, but I'd estimate about the same 1100-1500lm from each. If the lights are 10W-20W, that would make the standard stock electric wheel 500W-1000W. That seems kinda feasible to me, but I know way more about lights than motors. So far as battery and solar panels go, I'm not sure how they compare to reality. I've heard they are pretty crap compared to those on the ISS, but that's hearsay. Alas, if only I had the time, I could code a mod that would balance the power requirements and supplies in KSP. Oh, I'd also need to learn how to code...
