February 23, 2023
Research Highlight

Long-Term Basin-Scale Hydropower Expansion under Alternative Scenarios

A scenario approach was used to explore the potential future role of hydropower around the globe

Photograph of a dam surrounded by a forest.

The Ross Dam in Washington. Basins in the Pacific Northwest have relatively high hydropower potential compared to other basins in the United States, allowing for more future hydropower growth. Globally, the Congo Basin has the largest hydropower potential.

(Photo by Ying Zhang | Pacific Northwest National Laboratory)

The Science                                 

Hydropower is an important source of clean energy, but hydropower’s future expansion will depend on many factors. These factors include the location and amount of water available for hydropower, hydropower costs compared with other energy sources, and social factors like population and economic growth or energy system transitions. Studying future hydropower expansion is complex due to the diverse and interactive nature of these factors. Using a global multi-sector model, researchers projected future hydropower expansion for every major river basin in the world while considering the impact of several factors.

The Impact

Only a few global multi-sector models currently exist. These models represent key processes in inter-linked human and Earth systems and provide insights into future global environmental changes under alternative scenarios. However, these models have historically represented hydropower very simply. Based on a literature search, this study is the first to implement dynamic hydropower expansion at river basin scale in a global integrated multi-sector model. This work sets the stage for important future research, particularly given hydropower’s intersection with multiple sectors. For example, hydropower expansion could store water for direct use or store energy to produce electricity at times when it’s most needed.


Global and regional energy systems, including hydropower, may evolve in a variety of ways under different possible futures. Representation of hydropower in global multisector models is often simplified at the country or regional level. Some models assume a fixed hydropower supply, which remains unaffected by socio-economic drivers or competition with other electricity generation sources. Researchers implemented a dynamic model of hydropower expansion in the Global Change Analysis Model (GCAM), including a representation of hydropower potential at the river basin level. They then used GCAM to project future hydropower production across river basins and explore hydropower’s role in evolving energy systems under alternative scenarios. Each scenario makes different assumptions about future energy system transitions, technology costs, and energy demand. This study suggests there is ample potential for future hydropower expansion to help meet growing electricity demand. However, hydropower expansion will be constrained by resource availability, resource location, and cost relative to other technologies. As a result, all scenarios show growth in total hydropower generation with a decrease in hydroelectricity as an overall percentage of global electricity generation. Overall, the scenarios entail global hydropower generation growth between 36 percent and 119 percent globally in 2050 compared to 2015. Hydropower expansion varies across regions and river basins within regions.

PNNL Contact

Marshall Wise, Pacific Northwest National Laboratory, marshall.wise@pnnl.gov


This research was supported by the Department of Energy, Office of Science, as part of research in Multi-Sector Dynamics, Earth and Environmental System Modeling Program.

Published: February 23, 2023

Zhang, Y., M. Binsted, G. Iyer, S. Kim, T. Wild, and M. Zhao. 2022. “Long-Term Basin-Scale Hydropower Expansion under Alternative Scenarios in a Global Multisector Model.” Environmental Research Letters, 17(11), 114029. [DOI: 10.1088/1748-9326/ac9ac9]