Battery storage systems for peak load shaving applications: Part 1: Operating strategy and modification of the power diagram

Battery Energy Storage Systems (BESSs) are gaining more and more attention in the current global energy landscape, thanks to some peculiar characteristics such as the versatility, modularity, scalability, fast response time, etc. BESSs can advantageously be used in the ancillary services market, in order to provide all the services necessary to ensure the stability and the reliability of the power system. Among other applications, BESS can also be used to shift electricity demand from on-peak to off-peak periods, also contributing to relieve peak demand charges, thus ensuring a saving for the customers. The BESS is charged when the electricity prices are the lowest (during the night) and discharged when the prices are the highest (during the daily hours), contemporary achieving a leveling of the daily usage pattern. This paper is the first of a two-part series, aiming to evaluate the economic feasibility of electrochemical storage systems in peak load shaving applications. The sizing and the operating strategy of the BESS are defined, so as to obtain, at the same time, the flattest daily usage pattern and the maximum benefit for the customer. A case study is analyzed, showing the modification of the power diagram when the BESS is added. The simulation results show a customer daily power profile perfectly leveled in shoulder seasons and a peak shaving effect in all other days.