Multiobjective optimization and parameters study of hybrid offshore wind and pumped hydrostorage power system: Modeling and case study.

Offshore wind energy has been widely exploited as a promising renewable energy source in China in recent years. This renewable source's high curtailment rate due to strict wind energy penetration limits, however, remains a challenge of concern. Also, the difference between peak and valley loads of electric power systems continues to increase with economic and societal development. To address these issues, this study proposes a hybrid system composed of a high-capacity offshore wind farm coupled with a pumped hydrostorage (PHS) power system to absorb rejected wind power. The hydraulic energy stored by PHS system is expected to provide guaranteed energy during peak load demands on the main power grid. This study presents a multiobjective technoeconomic assessment model based on the principle of dynamic economy for optimizing the size of the PHS system. The conclusions can be summarized as follows: (1) the seasonal characteristics affect the utilization of wind energy; (2) PHS operating strategies have an influence on the PHS configuration, energy utilization, and economic benefit; (3) reducing the wind curtailment is the key to improve the system performance and economic feasibility; (4) the drop in water level has a negative effect on economic benefit and (5) provides clear guidance to set external financial parameters for a hybrid power station. The results show that a size-optimizing study is important in determining the system's economic feasibility and predicted performance. [ABSTRACT FROM AUTHOR]