Abstract:

In this study, the mode of conserving income for the electricity and subsystem investment costs of the battery energy storage system (BESS) is analyzed based on a two-part tariff. An economic mathematical model of the user-side BESS is established for a large industry enterprise, whose transformer capacity is above 315 kVA. Considering the seasonal feature of the time-of-use electricity price in a specific region and the hourly load characteristics, different typical days are extracted as the calculation object of the model. A lithium iron phosphate battery with high safety, high charge-discharge efficiency, and long cycle life is selected as the BESS charging medium. The model parameter constraints are set. The regional subsidy policy is also considered. Taking the optimal economy of the energy storage device as the goal, the BESS configuration, including the rated capacity and the rated charge–discharge power, and the charge-discharge strategy are calculated using genetic algorithms. In addition, a large industrial enterprise in Suzhou is taken as an example for calculating the BESS using the established model. The optimal system configuration, optimal system charge-discharge strategy, and system recovery period are obtained under two modes: ① peak load shifting and ② peak load shifting combined with load demand regulation. Accordingly, the scientific method for calculating the configuration, charge-discharge strategy, and payback period of the user-side BESS are provided. By comparing the configuration and the payback period of the BESS under the two modes, we conclude that considering the load demand regulation income would effectively reduce the system payback period and provide favorable conditions for the large-scale commercialization of the energy storage technology.

Key words: user-side battery energy storage system, system configuration, charging strategy, payback period