A home battery.
A home energy cell supercharge your solar panels, allowing you to use your solar at night, making you totally independent from the grid.
If you have solar panels it will allow you to power your home with sun power day and night.
It will also kick on when the grid is under intense demands, helping to relieve strain on the State's resources. This is why the State of California will reimburse you for installing it on your home. For more information on this incentive, go to the California Utility Commission's Website.