Battery Energy Storage Degradation Impact on Network Reliability and Wind Energy Curtailments

Transmission network flexibility is a great challenge to network operators. This challenge increases with the high wind integration that leads to stressing network components and reducing network reliability. However, due to the capacity constraints of the overhead lines (OHLs) as well as the network reliability requirements, a noticeable part of the integrated wind energy needs to be curtailed. This induces wind curtailment costs based on contracted obligations with the wind energy providers. To that extent, this paper develops a reliability evaluation framework utilizing large-scale battery energy storage systems (BESS) for minimizing network interruption cost and wind curtailment costs. Moreover, it investigates the extra benefits on reliability and wind curtailments from the elevated depth of discharge operation of the BESS (i.e. accelerated BESS degradation). Two indices are developed to capture the BESS degradation risks named expected accelerated degradation costs (EADC) and expected equivalent cycle accelerated degradation (EECAD). The proposed approach is implemented on the 24 bus IEEE Reliability test system using sequential Monte-Carlo simulation. The results show an improvement in the system reliability and wind curtailments with a reduction of 28% and 34% in interruption and wind curtailment costs respectively.