Actually, for the Albany, NY area, only 4.3 hours per day are considered realistic hours of sun averaged over the year.
Regardless, for a typical 4 KW system, It will generate over 500 KWh per month. For 20 years. "Payback period" depends on Congress, and how green your state laws are...
Pumblechook said,
I beg to differ.
Although solar panels may take years to payback their initial cost, you must consider their "free" energy after that.
Without the investment today, what will you be paying for energy then?
BTW, a 60 watt solar panel will generate 60 watts minimum in full sun.