In this area PV is not very efficient but solar water heating is ... you might want to look into that as an alternative. In combo with a tankless water heater in series as a backup it can not only just give you hot showers but run through radiant heating system heat at least your top floor very nicely and if logistically possible even heat most of the home.
Alternate Solar Thermal & Radiant Heating Combo Systems | 100K House Blog