Almeida R, Shi Q, Gomes-Selman JM, Barros N, Forsberg B, Garcia-Villacorta R, Hamilton SK, Melack JM, Perez G, Sethi SA, Gomes CP, Flecker AS. Reducing greenhouse gas emissions of Amazon hydropower with optimal dam planning. Nature Communications 12:4281
Hundreds of hydropower dams have been proposed throughout the Amazon basin, one of the world’s largest untapped hydropower frontiers. While hydropower is a potentially low emissions source of renewable energy, some hydropower projects produce high greenhouse gas (GHG) emissions per unit electricity generated (“carbon intensity”). We develop a basin-wide computational optimization framework to quantify the potential carbon intensities of 158 existing and 351 proposed hydropower dams in the Amazon basin. Results indicate carbon intensities of upland dams (median = 37 kg CO2eq MWh-1, 100-year horizon) may be comparable with solar and wind energy, whereas some lowland dams (median = 175 kg CO2eq MWh-1, 100-year horizon) may exceed carbon intensities of fossil-fuel power plants. Our analysis framework indicates that low-carbon expansion of hydropower may benefit from optimization-based planning, where basin-scale analysis that considers GHG emissions along with multiple social and ecological decision indicators associated with dams may advance sustainable energy development in regions where new hydropower is contemplated.