Technical analysis of peak shaving and load smoothing with battery energy storage systems in a distribution grid

Summary:

Many use cases for lithium-ion based battery energy storage systems (BESSs) seem to be of interest. In particular, reducing the peak power demand in the industry sector or power supply for fast charging stations are seen as two of the most prominent applications for BESSs. However, most publications dealing with these peak shaving applications focus on the economic optimization for a commercial electricity consumer. In most cases, the impact on the connected distribution grids is neglected.

In this contribution, we analyze the impact of lithium-ion based BESSs in peak shaving applications on the distribution grid. In a first case, we analyze the effects when operating the BESS in a typical market oriented fashion reducing the customers’ peak load with appropriate power when a load peak threshold is surpassed. This resembles a most profitable operation in today’s market conditions (peak-power tariff based electricity charge reduction). Furthermore, scenarios are simulated, in which the BESSs operate in a centralized approach to reduce the peak load at the point of common coupling (PCC). Finally, an approach to use and control BESSs at specific nodes aiming to reduce both PCC and local peaks is introduced. The use cases are tested for a synthetic example grid using the open-source tool “open_BEA”, which combines previously disjoint tools to enable accurate co-simulations of BESSs and distribution grids. The power flow analysis is conducted using the open-source tool “eDisGo’ and the behavior, which includes capacity decrease and battery as well as power electronic losses of the BESSs is analyzed using the open-source tool “SimSES”.

The simulations verify and quantify to what extent the various peak shaving strategies contributes to a reduction of peak load at the PCC in a distribution grid. Finally, the (dis-)advantages of all strategies are discussed in the poster slides.