Credible Capacity Accounting for Energy Storage Based on the Effective Load Carrying Capacity Method

Accurately quantifying the capacity value of energy storage systems (ESSs) is critical to ensure resource adequacy in renewable energy-dominated power systems. Traditional capacity credit assessment methods often fail to address the bidirectional operation and temporal coupling constraints inherent in ESSs. In this paper, an enhanced electric load carrying capacity (ELCC) framework that can be used for efficient capacity credit quantification is proposed. Firstly, the reliability index of the initial power system is presented to obtain the loss of load probability and loss of load expectation; Secondly, the optimal dispatching model of the power system with the energy storage is built; then the equivalent load increment calculation method is presented to obtain the trusted capacity. Finally, case study on a power system comprising 10 thermal power units with a total installed capacity of 1.8 GW is performed to demonstrate the validity of the model proposed in this paper, illustrating the need for a dynamic, time-varying evaluation framework to optimize ESS deployment strategies in power systems.