Almeida R, Fleischmann A, Brêda JPF, Cardoso DS, Angarita H, Collischonn W, Forsberg B, García-Villacorta R, Hamilton SK, Hannam PM, Paiva R, Poff NL, Sethi SA, Shi Q, Gomes C, Flecker AS. (2021) Climate change may impair electricity generation and economic viability of future Amazon hydropower. Global Environmental Change, 71:102383.
Numerous hydropower facilities are under construction or planned in tropical and subtropical rivers worldwide. While dams are typically designed considering historic river discharge regimes, climate change may induce large-scale alterations in river hydrology. Here we analyze how anticipated future climate change may affect river hydrology, electricity generation, and economic viability of >350 potential hydropower dams across the Amazon, Earth’s largest river basin and a global hotspot for future hydropower development. Midcentury projections for the RCP 4.5 and 8.5 climate change scenarios show basin-wide reductions of river discharge (means, 13 and 16%, respectively) and hydropower generation (19 and 27%). Declines are sharper for dams in the Brazilian Amazon, which harbors 60% of the proposed projects. Climate change may result in more frequent low-discharge interruption of hydropower generation and less frequent full-capacity operation. Consequently, the estimated minimum electricity sale price for projects to break even more than doubles at many proposed dams, impacting anticipated costs of proposed hydropower relative to alternative energy sources such as wind and solar.