Optimizing LiFePO4 Battery Energy Storage Systems for Frequency Response in the UK System

In the UK power system, there is currently no battery energy storage system (BESS) for providing grid-scale frequency response. However, according to the UK future energy plan, with a high penetration of renewable energy sources, battery technologies have become increasingly attractive to provide firm frequency response (FFR). This paper estimates the current and future balancing requirement of National Grid UK. A methodology for the economic optimization of the parameters of LiFePO4 BESSs is proposed to achieve the lowest tender price in the UK FFR market. The economic analysis is performed based on the estimated battery lifetime and the UK frequency regulation market. Results suggest that it is profitable to deploy BESSs in the UK market. The lowest tender price obtained was £17.4012/MW/h, which is already lower than many successfully tendered prices from FFR providers. By considering the future UK energy scenarios, a BESS with an energy/power ratio around 0.43, energy offset interval of 20 min and state of charge set-point = 50-60% is shown to be the optimal choice.