WASHINGTON — In southwestern Pennsylvania, eight locks and dams that for decades helped barges move goods along the Allegheny, Monongahela and Ohio rivers will in a few years also generate enough power for 75,000 homes.
Rye Development, a Boston-based hydropower company, is retrofitting the dams with turbines to generate electricity. It says the upgraded structures will limit damage to the rivers’ water quality and fish.
The project reflects a recent thawing between the industry and conservation groups, which had long opposed dams that can prevent fish migration and alter water temperatures. As the U.S. pushes to transition to low-carbon energy, Rye is among the companies that see an opportunity to expand hydropower production at existing dams while working to minimize environmental harm.
The recent compromises between the industry and environmental groups are reflected in President Joe Biden’s infrastructure law, which puts $2.5 billion toward projects including dam removals as well as upgrades at existing structures for hydropower and energy storage.
“We do recognize that (hydropower) is probably going to play some role in the transition. It’s certainly better than coal,” said Ted Illston of American Rivers, which has advocated for dam removals on environmental grounds.
Hydropower, which uses flowing water to spin turbines connected to generators, is the oldest and second-largest renewable energy source in the U.S. after wind power. In 2020, it accounted for roughly 7 percent of the electricity generated in the country.
The industry hasn’t received as much federal funding and tax incentives as wind and solar, but it sees room for growth. Of the 90,000 dams in the country, about 2,500 produce power. Non-powered dams could produce enough power for 9 million to 12 million homes, according to an estimate by the Electric Power Supply Association based on federal data from 2012.
Part of the challenge is that most dams in the U.S. were built more than 50 years ago. The risk of dam collapses has fueled demolitions in recent years, with more than 40 percent of the country’s nearly 2,000 dam removals in the past century happening in the last decade. Some are also torn down largely for environmental reasons.
Last month, federal regulators moved a step closer to approving what would be the largest dam demolition in U.S. history. Removal of the four hydroelectric dams on the Klamath River near the Oregon-California border would help save the river’s salmon and other fish species that can’t reach breeding habitat because of the structures.
The hydropower industry and conservation groups still clash over dams, too. On Maine’s Kennebec River, conservation groups and state environmental agencies are pushing for the removal of four hydropower dams that block endangered Atlantic salmon from reaching key habitat. The dams generate about 5 percent of the state’s renewable energy.
“It’s very easy for individual river systems to get lost in the message of climate change and the need for renewable energy,” said Shannon Ames, executive director of the Low Impact Hydropower Institute, which grades hydropower dams based on environmental criteria.
