Batteries are being developed around the world:
http://ecowatch.com/2015/09/21/batte...able-energy/2/
Off grid batteries like the Tesla powerpack are too expensive yet for most homeowners. Other home batteries exist, but don't last long enough. Staying on the grid seems the best solution at the moment for most people. But solar panels at home can still produce much of people's household needs, and being connected to the grid assures continuous power.
In the long run though, as batteries improve, then off the grid will be more viable. Staying on the grid will probably require paying a service charge, which is not the case right now in northern CA. Such a charge is counter-productive now when we are trying to ramp up alternative energy. But unless the utility companies want to become solar panel and battery companies, they will likely need to charge for grid service to stay in business. If off-grid becomes the norm, then these utilities may go the way of the do do birds. They won't be the first type of business to go belly up in this high-tech day and age.
We need to reduce carbon emissions now, so we can't wait until off-the-grid works for everyone. Allowing a 4C global temp rise is not acceptable. Meanwhile, salt batteries are being used at some solar power plants, and new kinds of batteries at solar and wind power plants will soon enable utilities to reduce reliance on nuclear and natural gas sources. Coal needs to be phased out as soon as possible.
Molten salt batteries
https://en.wikipedia.org/wiki/Sodium...sulfur_battery
From
http://www.ecmag.com/section/green-b...n-salt-storage
Published: February 2011 By Mike Breslin
Finally, there is a practical solution to store huge amounts of solar electricity that is generated by large-scale solar plants—molten salt technology.
In mid-December, SolarReserve, a U.S. developer of solar power projects, received environmental approvals from the Arizona Power Plant and Transmission Line Siting Committee to build its Crossroads Solar Energy Project. The 150-megawatt project will be located in Maricopa County, Ariz., and uses an advanced molten salt technology developed by Pratt & Whitney Rocketdyne, a division of United Technologies, Hartford, Conn.
List of energy storage projects:
https://en.wikipedia.org/wiki/List_o...orage_projects
The 150 MW Andasol solar power station is a commercial parabolic trough solar thermal power plant, located in Spain. The Andasol plant uses tanks of molten salt to store captured solar energy so that it can continue generating electricity when the sun isn't shining.[1]