Depending on your case. Where I live (NYC, a barebones Great Depression-era building) my electric bills skyrocket (3-5x) in the summer due to the house being he

Depending on your case. Where I live (NYC, a barebones Great Depression-era building) my electric bills skyrocket (3-5x) in the summer due to the house being heated by the sunlight. The roof is white, but it helps moderately. Heating in the winter takes much less energy, especially if we factor in all the electric devices inside that also release some heat. Storing a half-day's worth of electricity, and powering stuff from a solar panel at daytime, would likely let my apartment stop consuming external electric power in the summer. Assuming my apartment consumes no more than 15 kWh during the hottest days (according to the meter), a moderate 8 kWh battery, and $1000 worth of solar panels, would suffice, given the room and a permission to mount the solar panels somewhere.