I am not a big fan of trying to go totally photo voltaic, it is great for assisting alternative solar systems. Evaporation tubes for hot water, and sub-floor radiant heat will give you a much bigger bang for the buck. Skylights and lighting tubes are now available with both luminescent and thermal controls. Passive AC systems can pay for themselves in under 5 years. Add a thermostat controlled fan in a cupola and casement widows with wind sensitivity, thermal controlled tinting on storm windows, and subterranean fresh air vents, then you can pick up the other $30 a month in PV panels.