Optimal design of an autonomous solar-wind-pumped storage power supply system

Renewable energy, particularly solar and wind power integrated with microgrid technology, offers important opportunities for remote communities to provide power supply, improve local energy security and living conditions. The combination of solar, wind power and energy storage make possible the sustainable generation of energy for remote communities, and keep energy costs lower than diesel generation as well. The purpose of this study is to optimize the system design of a proposed hybrid solar-wind-pumped storage system in standalone mode for an isolated microgrid of a scale of a few hundred kW. The initial design process of the system's major components is presented, and then optimized based on a techno-economic evaluation. The optimal system configuration under zero loss of power supply probability (LPSP) is further examined. In addition, the system performance of hybrid solar-wind, solar-alone and wind-alone systems with pumped storage under LPSP from 0% to 5% is investigated and compared. Results demonstrate that addition of wind turbine can result in a lower cost of energy (COE) and help reduce the size of energy storage. Sensitivity analysis on several key parameters is also performed to examine their effects on system COE.