With the rapid development of wind power, the pressure on peak regulation of the power grid is increased. Electrochemical energy storage is used on a large scale because of its high efciency and good peak shaving and valley flling ability. The economic beneft evaluation of participating in power system auxiliary services has become the focus of attention since the development of grid-connected hundred megawatt-scale electrochemical energy storage systems (ESS). Based on the relationship between power and capacity in the process of peak shaving and valley flling, a dynamic economic beneft evaluation model of peak shaving assisted by hundred megawatt-scale electrochemical ESS considering the equivalent life of the battery is proposed. The model considers the investment cost of energy storage, power efciency, and operation and maintenance costs, and analyzes the dynamic economic benefts of different energy storage technologies participating in the whole life cycle of the power grid. Then, according to the current ESS market environment, the auxiliary service compensation price, peak-valley price diference and energy storage cost unit price required to make the energy storage technology achieve the balance of payments are calculated, and the economic balance points of diferent energy storage types are clarifed. Finally, based on the measured data of diferent provincial power grids, the economies of six energy storage types applied to three provincial power grids are compared and analyzed, and the rationality and efectiveness of the relevant models proposed are verifed. The work has theoretical guiding signifcance for the economic beneft evaluation of hundred megawatt-scale electrochemical energy storage.