Underestimated Climate Change Impacts on Hydro-Wind-photovoltaic Complementary Systems Due to Neglect of Short-Term Features

Hydro-wind-photovoltaic (PV) complementary power systems (HWPCSs) offer a promising solution for integrating intermittent wind and PV power. It is crucial to consider short-term features (e.g., variations in the hydropower efficiency and intraday curtailment characteristics) in the long-term HWPCS operation for achieving more accurate simulations. However, current long-term evaluations of HWPCSs under climate change normally neglect variations in short-term features that are difficult to be extracted, leading to potential misestimations of climate change impacts. This study proposes a generic framework to quantify this misestimation by extracting short-term features of HWPCSs from simulated daily operating samples. The short-term features are then incorporated into a long-term model to simulate operating results under climate change. Results of a case study in the Yalong River Basin validate that considering short-term features effectively increases the accuracy of calculating long-term HWPCS power generation. With the misestimation of both hydropower output and power curtailment, neglecting short-term features causes over-optimistic evaluations of future HWPCS performances. Specifically, the future HWPCS power generation and guaranteed rate are overestimated by an average of 1.02% and 1.09%, respectively, whereas the future power curtailment rate is underestimated by an average of 4.01%. The proposed framework contributes valuable insights for the long-term operation and evaluation of HWPCSs under climate change.