There are approximately 75,000 dams in the United States, with about 8,100 of them larger than 50 feet tall. If these major dams all generated power, it would help cut emissions in those local areas by pumping water back up to the top of the dam to turn turbines 24/7. There are no "non-windy" or "non-sunny" days with hydroelectric power. The dams are already there--just build turbines near them to harness the power of water!
Hydroelectric dams are a very effective way to cut carbon emissions in that they produce large amounts of clean, cheap, and renewable energy. Most alternatives by contrast either produce carbon (e.G. Coal and oil) or are often not economically feasible (e.G. Wind and solar). Hydroelectric dams produce energy that is both environmentally and economically friendly.