Battery power for solar has been tried before, and it has failed. The limitation is one of technology, the batteries have limited charge cycles, and lose capacity with each charge cycle. The issue with this is that, people who have installed a battery system instead of a reverse meter to put power back into the grid and receive a credit for them, have not saved money.
They will see lower bills for the first few years, but then the battery begins to fail the self tests, and then they need to replace it for a cost higher than all of the money that they had saved.
This is why the market has moved to people pumping the money back into the grid, and thus offsetting their electricity usage during the day (a decent system will essentially generate enough power to cover your electrical use, with some extra to put back into the grid. The credit then works to help offset the electrical energy that you use at night. This offers a consistent ROI, that will essentially last the life of the panels (upwards of 25 years depending on the quality).