The International Energy Agency released a report October 29 finding that doubling hydropower capacity by mid-century could reduce global CO2 emissions from fossil fuel plants by up to 3 billion MT annually. The joint report with Brazil’s Ministry of Mines and Energy, Technology Roadmap: Hydropower, surveyed hydro technologies ranging from run-of-river dams to reservoir plants plus pumped-storage hydropower. Hydropower in 159 countries is responsible for 16.3 percent of electricity generation worldwide.