FirstLight and Fishheart Ltd. Launch Innovative Fish Passage Project at Connecticut Hydroelectric Facility
Now in operation at the Tunnel Generating Station in Preston, CT, the project represents the first-of-its-kind large-scale installation in North America
Burlington, MA and New Milford, CT– May 15, 2025 – FirstLight, a leading clean power producer, developer, and energy storage company, today announced the successful launch of the Fishheart Ltd. (Fishheart) Hydraulic Fishway at the Tunnel Generating Station (Tunnel) in Preston, Connecticut, marking the official beginning of the three-year project at the facility. The hydraulic fishway, now in operation at Tunnel, also represents the first large-scale installation site for this unique technology in North America.
The Fishheart Hydraulic Fishway is a fish passage system that includes a floating hydraulic fishway unit placed below a dam, and a tube running over the dam. The system operates based on the siphon principle – it can be repositioned according to the river’s natural flows and produces an additional attraction flow, guiding fish to swim into the system and helping them find their way upstream. Once in the system, artificial intelligence detects fish in the tube and collects real-time data and photos of the migration. In the tube, fish are safely propelled upstream over the dam to continue their migration.
The Fishheart Hydraulic Fishway requires less permanent infrastructure to be constructed compared to traditional fishways, making it more adaptable and cost effective. Estimates suggest that a complete Fishheart Hydraulic Fishway costs approximately 20-30 percent of a technical fishway and 5-10 percent of a fish elevator.
“FirstLight is thrilled to partner with Fishheart to launch their innovative approach to fish passage at our Tunnel Generating Station in Preston, Connecticut,” said Justin Trudell, President and CEO of FirstLight. “Identifying successful, cost-effective fish passage approaches is absolutely critical to the outlook and growth of hydropower across the U.S. and beyond, and FirstLight is proud to be an early adopter of solutions that could be game-changing for our industry and our energy future.”
The project at Tunnel is intended to demonstrate the system’s ability to attract and safely guide target fish species with state and federal restoration goals, namely American Shad and River Herring, past the dam – and ultimately showcase the efficacy of the system as a successful, cost-effective solution for fish passage at other facilities across FirstLight’s operational portfolio in the U.S. and Canada. The Tunnel facility was selected as the initial test site because it is located on a small river with the target species present. This environment provides a controlled setting for evaluating the fishway’s efficiency. The fish passage system will operate for 2-3 months each year during the American Shad and River Herring migration season, which occurs between April and July.
The three-year project at Tunnel will serve as an important demonstration for state and federal fish management authorities, including NOAA’s National Marine Fisheries Service, the U.S. Fish and Wildlife Service (FWS), and Connecticut’s Department of Energy and Environmental Protection (DEEP). Approval from these agencies is crucial for the Fishheart Hydraulic Fishway to gain acceptance for permanent use in North America.
“Fishheart is pleased to launch the first large-scale installation of our fish passage technology at FirstLight’s Tunnel Generating Station – a key opportunity to demonstrate our innovative solution to the U.S. market,” said Mika Sohlberg, Vice President of Sales for Fishheart. “We are proud to partner with an industry leader like FirstLight to spotlight new approaches to fish passage that will support the resilience of key species and the availability of critical clean energy generation now and into the future.”
The launch of this project at Tunnel follows the successful test of the Fishheart Hydraulic Fishway on the Santee River in South Carolina in 2024. The system has also been successfully operating at four river sites in Finland for several years, and the company is currently running an additional test project in Menindee, Australia.