With the increasing integration of renewable energy generations, the renewables’ uncertainties impact the power system operation. So, it is critical to enhancing the system’s operational flexibility. To this end, one of the most useful solutions is to deploy energy storage. This paper proposes a power system flexibility enhancement method using energy storage systems (ESSs). The grid’s flexibility requirement is analyzed, and the flexibility enhancement model is constructed, considering the ESSs’ charging and discharging characteristics. Case studies on an IEEE 33-node system verify the quantitative method. The conclusions indicate the ESSs could efficiently meet the system’s flexibility requirements.

Energy storage station (ESS) has been allowed to provide ancillary services in power markets in recent years. It is a high-quality resource for regulation services and can promote renewable energy consumption. Existing studies have yet to consider the battery degradation cost when using ESS to provide regulation service. This paper establishes a model to quantify the ESS’s degradation cost and proposes a market-clearing model integrated with such a cost to address this issue. The model is verified by case studies. Key factors affecting the revenue and performance of ESS providing regulation services are also analyzed.