Energy Storage Sizing and Reliability Assessment for Power Systems with Variable Generation

Energy storage systems (ESSs) mitigate the problems introduced by variable generation (VG) and offer the ability to optimize the operation of power systems with VG. The cost of ESS dictates prudent planning and installation of ESS to achieve specific objectives. This paper presents a mixed integer linear programing (MILP) model for ESS sizing. The model determines the optimal power and energy sizing of ESS taking into account forced outage rates (FORs) of all generating units including VG units (wind turbine systems (WTSs) and solar cell generators (SCGs)) and operational practices of dispatchable units, mainly economic dispatch. For specific sizes of ESS, we evaluate the reliability and projected costs in a probabilistic manner. For demonstration of the method, the ESS sizing and reliability assessment is applied to a power system with 10 conventional generators (CGs) and different numbers of SCGs and WTSs, depending on VG penetration level.