In the context of the electricity market and a low-carbon environment, energy storage not only smooths energy fluctuations but also provides value-added services. This paper explores energy storage planning and operation scenarios under two-part tariff electricity pricing. It proposes an optimization method for power and capacity allocation throughout the energy storage system's lifecycle, along with a performance evaluation model. Under time-of-use pricing, the optimization objective is to minimize the annual comprehensive cost, considering low storage and high discharge arbitrage revenue, demand management revenue, and power outage supply revenue. By applying mixed-integer programming and integrating actual engineering practices, the case study determines the optimal charging and discharging power and capacity configuration parameters for the energy storage system under the two-part tariff. It then compares the benefits of various business models, including low storage and high discharge, demand management, and peak-shaving ancillary services. The study also analyzes the impact of cycle times, capacity, peak-valley price differences, and demand management on benefits and investment boundaries. The simulation results verify the reasonableness of the constructed model, which has a high benefit.