Energy management strategy and optimal battery capacity for flexible PV-battery system under time-of-use tariff

An appropriate battery capacity and a reasonable energy management strategy can improve the techno-economic characteristics and the energy flexibility for building energy systems. In this study, integrating the battery roles of the PV self-consumption maximum, peak shifting, and price arbitrage, a new operation strategy defined as MF strategy is proposed by setting the charging/discharging ratios for PV-battery system with time-of-use tariff. Compared with the single-objective optimization based on the MINLP model, the calculating time based on the MF strategy is reduced by 45 h, and the SCR is increased by 8.73%. Compared with the multi-objective optimization based on the SCM strategy, the optimal battery capacities based on the proposed MF strategy have a lower total cost, and the optimal SCR range is 77%–86%. Moreover, the sensitivity of 14 parameters on the energy system performance is analyzed by local and global sensitivity analysis. The analyses showed that the important parameters for the total cost include the charging/discharging ratio for the shoulder period. The important parameters for the SCR include the charging/discharging ratio for the shoulder period and discharging ratio for the peak period. This study provides a new operation strategy and algorithm for battery capacity optimization and energy management.