Capacity optimization and feasibility assessment of solar-wind hybrid renewable energy systems in China

The solar-wind hybrid renewable energy systems, including wind farm, photovoltaic (PV) plant, concentrated solar power (CSP) plant, electric heater, battery, and bidirectional inverter, are analyzed in 36 typical locations in China. The effects of wind and solar energy resources on power supply reliability and economy and the optimal installed capacities are analyzed. The regions in China recommended for the development of the systems are given. Results show that the levelized cost of energy (LCOE) of system in Huade can be as low as 0.1 $/kWh when 90% of annual load demand is met. The wind speed and solar irradiation have a major effect while the complementary characteristics of wind and solar energy have an auxiliary effect on power supply reliability and cost of the system. Compared with the system in Tongliao, the LCOE of system in Qiqihar with lower wind speed and solar irradiation intensity is reduced by 9.8% due to the better complementary characteristics of wind and solar energy. For systems in locations with different wind and solar energy resources, the wind farm or PV plant is still the technology with the greatest cost advantage but the worst power supply reliability. The electric heater with thermal energy storage and power cycle is an essential factor to greatly improve power supply reliability economically. Meanwhile, one of the solar field and battery should be integrated into the system according to the direct normal irradiance conditions. When high power supply reliability is pursued, the CSP plant is recommended to be introduced in most regions. Moreover, the commercial promotion of CSP plant brings the most significant economic benefits to the system. As the CSP plant cost is reduced by 30%, the LCOE of system is reduced by 20.4%. •Capacities of complex solar-wind systems are optimized in various locations of China.•Wind and solar energy intensity and complementarity affect system performance.•Electric heater with TES and power cycle can greatly reduce LPSP economically.•CSP plant is recommended to be introduced in most regions when low LPSP is pursued.