http://www.theverge.com/2015/2/11/8023443/tesla-home-consumer-battery-elon-musk

Musk is going to produce a battery that can power your house. Both Toyota and Nissan say their batter packs can power your house.

With that kind of battery, you can charge the battery with solar, or use grid power in the middle of the night when electricity prices are lowest. This could massively reduce everyone's electricity bills. It also means we're not far off of everyone actually being off the grid if they so desire.