Wind and solar energy have grabbed headlines with their meteoric rise in recent years, but hydropower still provides far and away more energy than any other renewable source, accounting for 7 percent of total U.S. production. But there are only so many rivers to dam, and America did a pretty good job of that all throughout the 20th century. So it’s not uncommon to hear hydropower described as being “tapped out,” and indeed growth in hydro capacity has essentially flatlined since the early 1990s.
That’s starting to change, says Jeff Leahey, deputy executive director of the industry group National Hydropower Association. “The policy arena has shifted and there’s been more of a focus on clean energy investments and that’s driving people to look at hydro,” he tells CityLab. “Now we’re seeing that growth curve uptick again, when in the last 20 years it’s been pretty flat.”