Future Amazon Hydropower under Climate Change

Current climate and hydrologic models point to significant decreases in precipitation and runoff in many parts of the Amazon River Basin by the end of this century. Implications of this climate change for future hydropower have been little explored across the basin, a global hotspot for future hydropower development. We used a continental-scale hydrologic model forced with an ensemble of general circulation models to project changes in river discharge and hydropower generation at >350 proposed dam sites throughout the Amazon. We found that discharges are projected to slightly increase in the Andean Amazon and sharply decrease in the lowland Amazon. In the lowlands, reductions in hydropower generation are disproportionately larger than reductions in discharge due to an increased frequency of discharges below the minimum usable flows. In the Andes, increased discharge will not necessarily translate into higher hydropower generation if the dams are operated as run-of-river (i.e., with minimal flow regulation). Consideration of climate change-induced alterations in hydropower generation may substantially diminish the economic feasibility of many proposed Amazon hydropower dams. Climate-resilient energy system planning will be fundamental in the Amazon and other hydropower-dependent regions where river discharge regimes will be affected by climate change.