Economic analysis of an industrial photovoltaic system coupling with battery storage

The Energy and Evaluation Special Committee of the China Price Association proposed two types of bill for battery energy storage (BES) subsidies in 2017: the first was that energy storage should be subsidised based on the initial installation capacity of BES system, while the second was that it should be subsidised based on the energy discharged by the BES system during the operational period. The economic benefits of a distributed photovoltaic (PV) system or a distributed system with PV and BES in the overall life cycle are discussed in the context of an industrial zone in Shanghai. The results suggest that the net present value (NPV) of a PV-BES system with an optimised configuration is higher than the NPV of a PV system alone. The NPV of a distributed PV system with four different BESs is found to decrease in the order Li-ion > NaS > VFB > Pb-C because of the characteristics of their batteries. The NPVs of PV-BES systems increase in equal proportion to the increase in the BES subsidy based on installation capacity for these four BES systems, while they show an inequable growth rate of earnings for the same BES subsidy based on the energy discharged over the operational period. The second bill for BES subsidy is more beneficial to the BES industry than the first, as it encourages higher pay for more work.