A solar battery stores excess power for later use. In conjunction with a photovoltaic system, solar power can also be used when there is no sunshine, i.e. when the solar modules do not currently generate any electricity.
Through the use of the battery, more of the solar electricity produced can be used. The electricity has not to be fed into the grid in order to buy it later at a high price. Due to the increased own consumption, the electricity costs decrease significantly.