As long as I’ve been installing solar, clients ask about what happens when the grid goes out?… I then end up explaining that ‘grid-tied’ solar generators have to shut-down to be compliant with local code.  For this, and a few other reasons, solar won’t work when the power is off.   
Enphase Energy has finally produced a ‘system’ (that they have aptly named Ensemble) that solves this problem.  The magic here is two-fold.  First and foremost, their latest series of micro inverters will form its own grid and these units are incorporated into the battery portion of Ensemble.  Secondly, a very fast switch automatically isolates your home and batteries from the grid when the power goes out to allow the system to form a ‘micro-grid’ and power critical items in your home.  It’s sleek, functional and allows your solar to keep working when the power’s out – I love it!