Presumably, the only cost in solar panels is their construction, so there are no recurring costs (other than amortizing their lifetime). It seems complicated to

Presumably, the only cost in solar panels is their construction, so there are no recurring costs (other than amortizing their lifetime). It seems complicated to figure the number of hours it lasts for, and figure out the energy generated in those hours. It's a lot simpler to figure out the amount of power generated for a given surface area (in some standardized amount of light input), and the cost of that surface area to generate. So if you wanted a kilowatt of power generated continuously from the sun, minus overcast and such, it would cost $400. I'm not an expert, but that would be my guess.