Optimal capacity and operation strategy of a solar-wind hybrid renewable energy system

•A solar-wind system with multiple power plants and energy storage devices is studied.•The multi-objective optimal system combinations are obtained.•Integrating CSP plant into PV plant can greatly reduce LPSP in an economic way.•Integrating battery to reduce LPSP economically is highlighted when its cost is low.•The operation strategy of power cycle output prior to battery output is recommended. A hybrid renewable energy system, including photovoltaic (PV) plant, wind farm, concentrated solar power (CSP) plant, battery, electric heater, and bidirectional inverter, is proposed. The optimal combination of power plants and energy storage devices, and their optimal capacities are obtained by the multi-objective optimization algorithm. A superior operation strategy of the system, which consists of multiple energy storage technologies and flexible power supplies, is proposed. Results show that the PV plant with an inverter can generate power at the lowest cost but with poor reliability. The combination of the CSP plant and PV plant is an effective way to improve power generation reliability economically. When low investment costs of PV plant, battery, and inverter are adopted, the battery is preferentially integrated into PV plant to reduce the loss of power supply probability (LPSP) to a certain level. But it still cannot meet the high power generation reliability requirements. The CSP plant is still an essential technology to further significantly reduce LPSP with good economic performance. The operation strategy in which the power cycle takes precedence over the battery to supplement the power shortage is recommended. The levelized cost of energy (LCOE) of the system with power cycle output priority is 8.36% lower than that of the system with battery output priority when the LPSP is 1.34%.