This calculator says that I will lose $500 a year
with a white roof, using San Francisco as my location.
Calculating my actual AC costs are only about $25 a year.
I only use the AC about 10 days a year,
KWH .17 / 3000 Watts / 5 hours per day = .50/hr
= $2.50/day X 10 days = $25.00 year