Wind, solar, dams and wave. They may not replace coal and other fossil fuels today but we can substitute a lot of our energy needs with a concerted effort into those renewables.
Hydro is also terrible for river ecology. Egypt gained a multi-billion dollar fertiliser industry (that didn't exist before) after they added dams to the Nile.
Dams hold back silt and sediment essential to farm land and despite everything you learned about fish ladders and salmon, they don't really work as well as the power companies say.
