Here is a very good analysis of the batteries market from Clean Technica.
Interestingly, I just came across of the residential installation using Powersonic 2V AGM sealed batteries - 1300 Ah (20 hr rate). Twelve batteries deliver 31 kWH and provide complete off-grid service combined with the array of 24 Conergy PV modules. These batteries appear to be much better deal than offered by Musk: $206/kWh
(CAD) vs. $350/kWh (US) for Tesla Powerwall or even $250/kWh (US) for the commercial pack.
One important aspect is not usually highlighted in most analyses. Creating on-site energy can not only reduce the load on the grid, but eventually lead to the grid become unnecessary. Autonomous systems will not require power lines, thus avoid losses associated with transmission. They will be protected from disruptions in the centralized grid (either caused by natural disasters, technical glitches or terrorism) and will not impact other individual systems, therefore safer.
Integrated solar thermal system supported by off-grid electrical generation is one of the best options for future clean reliable and safe energy.