“First, do no harm” is a phrase associated with health care professionals, but it also applies to sustainability practices. Clean energy deployment is as much about reducing harm (pollution) as it is about reducing costs, and when it comes to hydropower—which provides nearly one-third of renewable electricity generation in the United States and is growing—a key area of concern is the safety of ecosystems and species, especially fish.

Natel Energy developed a solution validated by Pacific Northwest National Laboratory (PNNL) to keep fish safe while supporting the growth of hydropower, which increases the reliability and resilience of the nation’s power grid. With nearly $9 million in funding from the U.S. Department of Energy’s (DOE) Water Power Technologies Office (WPTO) awarded across seven programs over eight years, Natel created its Restoration Hydro Turbine (RHT), an innovative technology designed to make it easier for fish to navigate through hydropower facilities without getting hurt.

Natel developed RHT by changing the turbine’s design to include thicker blades with rounded leading edges and a forward slant from the blade’s hub to its tip. This design also reduces installation costs by eliminating the screens that are typically used to divert fish from entering turbines. And the RHT is compact, so it can be installed in a variety of hydropower facilities.

With PNNL, the team tested through-turbine passage of American eel that were about 13-26 inches long, rainbow trout 8–16 inches long, and rainbow trout 16–20 inches long. The American eel and the smaller rainbow trout passing through the RHT had a 100% survival rate including following a 48 hour observation period. All the larger rainbow trout also made it through the turbine, with <1% delayed mortality for an overall 99% passage rate for all fish studied.

This makes Natel’s turbine the first in the industry to enable safe fish passage for large and small fish while meeting high performance metrics and matching standard installation configurations, and demonstrates significant progress in efforts to preserve biodiversity while advancing renewable energy production.

The first RHT was installed in 2019 in Freedom, Maine, followed by a second utility-scale installation in Madras, Oregon, in 2020. A third installation will be completed in Austria this year with another U.S. installation scheduled for 2023. Additionally, Natel is retrofitting three dams in Louisiana, which are operated and maintained by the U.S. Army Corps of Engineers, with up to 90 RHTs to produce a total of 80 MW.

“To move the needle on climate change, hydropower must be part of the solution,” says Gia Schneider, co-founder and CEO of Natel Energy. “Our studies with PNNL conclude that hydropower can preserve fish species that are critical to societal and ecological health while helping the planet reach net zero emissions.” 

Learn more about WPTO’s work to enable innovations for low-impact hydropower growth.

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