The study’s authors examined 351 proposed hydropower projects in the Amazon basin. Their findings suggest that hydrologic shifts by midcentury will reduce hydropower generation at many locations. As river discharge becomes increasingly variable and hydropower output declines, alternative energy sources like solar and wind are expected to become ever more important.
Co-author Stephen Hamilton, an ecosystem ecologist at Cary Institute of Ecosystem Studies, explains, “Hydropower projects in the Amazon basin are designed to operate under flow regimes based on historic river levels. Climate change is disrupting these patterns, meaning that many existing and proposed projects are unlikely to be as effective under future conditions.”
Using several climate change scenarios defined by the IPCC, the team modeled continental-scale changes in precipitation and river discharge to see where and how hydropower production is likely to shift. They also estimated changes in energy costs, comparing costs of hydropower to solar and wind energy in the Amazon region.
Continent-scale changes in precipitation and runoff, which influence river discharge, were estimated using general circulation models that use climate data to project future precipitation trends. Inputs include information on air temperature, humidity, wind speed, solar radiation, pressure, and precipitation. Power output at proposed dam sites was estimated using information on the maximum and minimum river flows at each site under both current and future climate conditions.