Thanks for the replies. Some more background - we're looking at rooftop photovoltaic to funded by rebates/refunds and a significant offset of utility power. Placing the PV on the roof would involve removing existing solar thermal. It's 24 years old (installed by prior owner) and I want to include pool heating into my cost-benefit analysis. It seems that if I am considering going PV anyways, I should factor in sizing it x% larger to replace my 24-year old supplemental gas pool heater with an electric pool heater.

I'll let you know what I come up with.

California Newbie