To put some numbers to things, using this calculator, I could generate ~14,000 kwh per year with typical panels on my roof. According to wikipedia, the average US household uses ~17,000 kwh per year of energy (n.b., not electricity). 3/4 of that is HVAC. An air-source heat pump might have a coefficient of performance of 5, in which case the actual electricity requirement would be 7,000 kwh per year.

Basically, I could generate double the average household needs, so I could deal with a hit to panel efficiency. Granted, that's only for domestic energy consumption. If you factor in things like food production, transportation, water treatment, etc, my consumption would be higher.