As battery technology continues to improve, so do the uses for the batteries. Panasonic is working on a storage cell with enough capacity to power a standard Japanese home for a full week.
The home battery cell should be available in Japan in 2010 according to Panasonic President Fumio Otsubo. Panasonic has already been working on cell home cogeneration systems, but since it has taken majority control from Sanyo Electric things are going to get interesting. Expect solar and battery technology for the home to really progress in the next few years.