Automatic Generation Control Using an Energy Storage System in a Wind Park

This paper demonstrates the operation of a 1 MW/2 MWh grid-tied battery energy storage system (BESS) in a 10 MW wind R&D park for Automatic Generation Control (AGC) for 29 days. The efficiency and utilization of the BESS in the context of regulation and grid integration are examined. The response time for the BESS is as low as one second, which is faster than the current accepted practice of a conventional generator with governor control. Using PJM's performance template gives an average performance score of 93% while the storage is providing AGC. However, because the storage system only charges when there is sufficient wind energy and spent significant time in maintenance mode, the 29-day performance average is only 65%. The battery was able to carry out some mode of AGC for 64% of the test period. When energy costs and battery degradation are considered, utilizing the battery costs USD 19,000 over the 29-day period, whereas the potential income from AGC, charging only with wind power, was USD 9,037. This 29-day demonstration shows that batteries have fast response and can perform AGC, but within a wind farm AGC is unlikely to be suitable without changes in the tariff schemes.