Capacity Co-Optimization of Thermal and Battery Energy Storage System in Multi-energy Complementary System

Constructing the multi-energy complementary system with wind power, photovoltaic and concentrating solar power (CSP) as well as battery is an effective way to facilitate renewable energy integration. Coordinately optimization of battery and thermal energy storage capacities in CSP can help to reduce the investment cost and improve the renewable energy utilization. In this paper, a mixed integer linear programming model is formulated and system constraints such as renewable energy curtailment rate and operation constraints of each power plant are considered. The nonlinear thermoelectric conversion of CSP is approximated by the piecewise linearization method. Given the data of annual wind and solar power outputs as inputs, the optimal battery and thermal energy storage capacities which maximizes the equivalent uniform annual profit of system are obtained. Case studies are tested on a demonstration project of multi-energy complementary system in North China with a 300MW wind plant, 300MW photovoltaic solar station, 50MW CSP station and 50MW Li-ion battery. It is verified that the optimal capacities of battery and thermal energy storage are 194MWh and 1280MWht. In case studies, sensitivity of the system profit to battery capacity is also analyzed. The testing results validate the effectiveness of the proposed method.