Solar batteries store the energy that is produced by the solar panels and is not consumed instantly, in order to use it during the hours that we do not have solar radiation.
Physical batteries allow you to take advantage of the surplus of your solar installation, store it and consume it when you need it, thus improves even more the savings on your bill.

In addition, some retailers offer "virtual batteries", which function as if they are a savings box in which you accumulate your surplus production to generate energy savings.
The remaining production surpluses of your photovoltaic solar panel installation are accumulated as a positive balance to be deducted from the consumption of the network when your production is higher than your consumption.