Assessment of Multi-time Scale Dispatchable Capacity of the Electrochemical Energy Storage Station

This paper investigates the dispatchable capacity of electrochemical energy storage under high percentages of renewable energy penetration and the assessment of its costs under multiple time scales. As the global energy transition accelerates, the large-scale penetration of renewable energy into the power system has led to problems such as mismatch of supply and demand timing and increased frequency stability risk. Energy storage can be the key to improving power system flexibility and economics by providing peak and frequency regulation auxiliary services. This paper analyses the impact of energy storage aging and security margin on its dispatchable capacity and establishes an energy storage degradation model with comprehensive consideration of peak shaving and frequency regulation gain. The results, analyzed by actual data calculations, show that when energy storage is used for peak shaving alone, its saving effect on electricity cost is limited. However, when combined with frequency regulation service, it can significantly reduce the operating cost and achieve a higher economy. The study provides a theoretical foundation for the optimal operation of energy storage and new ideas for power systems to meet the challenges of renewable energy.