Payback Period of Hotel's Solar Panels
The payback period of solar panels refer to the number of years the owner gets back his investment. Your assumption is that the efficiency of the hotel's solar panels are really fantastic, so the limiting factor is the amount of energy utilized. However the fact is payback period is usually determined by the sun hours (i.e. Seattle area averages only 3.7 peak sun-hours per day). If there isn't enough sun hours at your location, the energy (= $$) output is gonna be really bad and the payback period will be longer. If the sun hour is fantastic, your solar panels will be generating enormous amounts of energy for you with only a few pieces of solar panels. So you'll be spending less while reaping more...thus your payback period is shortened. It all boils down to its cost per kilo watt.
Or suppose you have bought a really cheap solar panel with great efficiency or some DIY solar panels that you've built yourself, the cost per kilo watt goes down and so does your payback period.