Solar power system batteries? Yes, you can get them but this is a decision that deserves careful consideration. Until recently, adding batteries could be problematic, which is why most solar power systems do not use them.
There are 2 types of solar photovoltaic (electric) systems: one is grid-tied which is the common one for here in Massachusetts, and the other is off-grid which is used in very remote places where it is difficult or impossible to get electrical service from a standard utility company. Off-grid solar systems use batteries which store power that is produced during daylight and mostly summertime for use at night, rainy days, and during the winter. Grid-tied solar systems send excess power that is produced during daylight and mostly summertime back to the grid which gives a credit to the system owner so they can buy power at night, rainy days, and during the winter using those credits instead of cash out of pocket.
Furthermore, the solar power battery technology, until recently, has not been truly ready for home use. Batteries (such as automobile or marine batteries) were cumbersome and large, needed a safe storage place, and also needed to be swapped out on a regular basis. The big news is Tesla and Samsung have recently announced new batteries specifically designed for home use with solar or wind powered systems. These batteries will be more readily available some time next year. However, they still may not be appropriate for all homes, because if a homeowner stores their energy off grid, they may not be eligible for SRECs or other subsidies.
While it is theoretically possible to do so, to date we at RevoluSun have not yet installed a solar power system with a battery backup in Massachusetts.