Performance analysis of a wind-solar hybrid power generation system

•Focus on a thermal storage wind-concentrated solar power hybrid system.•A capacity configurations optimization method for the hybrid system is proposed.•The effects of the key parameters on the performances of the system are revealed.•Integrating the electric heat could significantly reduce the wind curtailment.•The stability of the output power is improved by integrating electric heater. In order to reduce wind curtailment, a wind-turbine coupled with a solar thermal power system to form a wind-solar hybrid system is proposed in this paper. In such a system, part or all of the curtailed wind power is turned into heat through an electric heater and stored in the thermal storage sub-system of the solar thermal power plant. To simulate and study the performance of the hybrid system, a simulation model of the hybrid system, which consists several modules/sub-models is developed. In addition, a capacity configurations optimization model based on particle swarm optimization algorithm is proposed to maximize the economic performance. An 80 MWe hybrid system in Zhangbei China is selected as the study case. The result shows that when the capacity ratio of the wind power generation to solar thermal power generation, thermal energy storage system capacity, solar multiple and electric heater capacity are 1.91, 13 h, 2.9 and 6 MW, respectively, the hybrid system has the highest net present value of $27.67 M. Correspondingly, compared to the conventional coal-fired power plant, it could reduce carbon dioxide emission by 15,470 tons per year. Besides, the sensitivity of each capacity parameter on the annual performances of hybrid system is analyzed in this paper. The results show that the electric heater can effectively reduce the wind curtailment and improve the overall system stability. The results also show that the hybrid system with bigger thermal storage system capacity and smaller solar multiple has better performance in reducing wind curtailment. And when the solar multiple is constant, mean power change rate decreases with the increase of thermal storage system capacity. The bigger the solar multiple is, the faster the decrease of mean power change rate is.