Abstract:
Variable renewable energy (VRE) generation alters residual demand curves, leading to high operating costs for conventional generators. Additionally, the variable nature of VRE causes a mismatch between electricity demand and generation, resulting in greater expected energy not supplied (EENS) values, which represent a critical component of power generation costs. To alleviate the impact of VRE, utility-scale battery energy storage systems (BESSs) provide ancillary services. The BESSs’ general applications are spinning reserve, regulation, and ramping. This paper proposes a method to determine daily operation schedules for grid-scale BESSs, compensating for the negative impacts of VRE on operating costs, power generation reliability constraints, avoided outage costs, and BESS installation expenses. The optimal BESS application at a specific time of day can also be selected. The method is based on a multiple BESS applications unit commitment problem (MB-UC) solved with mixed-integer programming (MIP). The results demonstrate that each application offers the best value for BESS operations at different times of day, and operating BESS in multiple applications results in more significant benefits.
