When electricity is generated from renewable sources (such as a photovoltaic power plant, a wind power plant, etc.), part of the electricity is not consumed by the facility where the renewable source is installed. The renewable source cannot store this surplus electricity and therefore must sell it at the price offered by the electricity off-taker at that time. In most cases, this price is low, and on weekends it is often even negative.

The main benefit of a battery storage system lies in its accumulation capability, i.e. the ability to store electricity generated either from renewable sources (such as photovoltaic or wind power plants) or from the grid, and to use it at the time when it is most advantageous for the facility.