Improving complementarity of a hybrid renewable energy system to meet load demand by using hydropower regulation ability

The hydropower regulation ability, as an important factor of energy complementarity, can be used to alleviate the fluctuation of wind and photovoltaic power for meeting the load demand, and should not be ignored. To address this issue, the study proposes a hydropower complementarity assessment method for a hybrid energy system considering the load demand variation of the power grid. To begin with, two complementarity assessment indicators, including time and magnitude, are proposed by accounting for the probability that the power output of a hybrid energy system matches the load demand. Then, the complementarity of a hybrid energy system is assessed considering varied installed capacities of wind and photovoltaic plants. The Guandi wind-solar-hydro hybrid power plant on China's Yalong River is selected as a case study. Results from the case study show that: (1) The proposed method is superior to the traditional complementarity assessment methods, such as Pearson correlation coefficient and fluctuation index. (2) The complementarity of the hybrid energy system is underestimated when the hydropower regulation ability is not considered, and the power curtailment rate is overestimated by about 20%. This study provides a new complementarity assessment method for a hybrid renewable energy system.(c) 2022 Elsevier Ltd. All rights reserved.