Impact of Droughts on Hydropower Generation using a new Global Hydropower Plant and Reservoir dataset (GloHydroRes) and Hybrid Modelling

Hydropower is a crucial renewable source reliant on water availability, making it vulnerable to climate change and hydroclimatic extremes such as droughts. Studying the connection between climate, streamflow, and hydropower generation is especially critical for hydro-dependent energy systems. However, analysing drought and climate change impacts on hydropower generation requires detailed data on both hydropower plant attributes (e.g. plant type and head) and reservoir characteristics (e.g. area, depth, and volume). Existing open-source datasets lack integration: hydropower plant datasets often lack reservoir information, while reservoir datasets frequently omit hydropower plant information.

To addresses this, we developed GloHydroRes, a new global dataset that combines existing open-source hydropower plant and reservoir datasets. GloHydroRes includes plant attributes (e.g., location, head, type) and reservoir details (e.g., dam and reservoir location, height, reservoir depth, area, volume) for 7,775 plants across 128 countries, covering 79% and 81% of the global installed capacity reported by the EIA (2022) and IRENA (2023), respectively.

Leveraging GloHydroRes, we developed a hybrid hydropower modelling framework that integrates physical model simulations with machine learning techniques to predict hydropower generation at plant level. Our validation results show that, the hybrid model outperforms the physical hydropower model. For instance, hybrid model results in 40% reduction in root mean squared error on average compared to the physical model across all plants.  

Our results reveal a significant reduction in hydropower generation during drought periods in regions worldwide, highlighting the vulnerability of hydropower systems to hydroclimatic extremes. By integrating detailed plant and reservoir data from GloHydroRes with physically-based and advanced machine learning methods, we enhance the accuracy of hydropower simulations while providing a valuable tool to support hydropower and water management and decision making within the water-energy nexus.