Project Nexus, the unique solar system being installed over an irrigation canal in California, has completed construction.
Launched in 2022, with construction beginning in 2024, Project Nexus is a pilot study designed to test how solar over canals can generate distributed renewable electricity while saving water and conserving land by utilizing existing canal infrastructure. The project tracks changes in water evaporation, water quality, aquatic weed growth and canal maintenance requirements, as well as electricity generation and other performance metrics, through in‑field research led by UC Merced. A full report on these findings is expected to be published later this year.
Project Nexus represents an innovative public-private-academic collaboration between the California Department of Water Resources (DWR), Turlock Irrigation District (TID), Solar AquaGrid and the University of California, Merced (UC Merced), which together developed and built this project over canals in California’s Central Valley.
“With its 250 miles of canals of various widths and orientations, TID has been the ideal host for Project Nexus. This has allowed us to construct solar arrays over both narrow and wide canals, which represent a cross-section of California’s 4,000 miles of canals,” said Jordan Harris, CEO and co-founder, Solar AquaGrid. “Our aim has been to identify and test different prototypes to evaluate performance, benefits, and risks, and to ultimately define a set of solutions to meet different canal operator requirements.”
Early results from UC Merced’s ongoing research already indicate reductions in evaporative loss and aquatic weed growth. Preliminary data gathered over one irrigation season indicate that shaded canals experience less evaporation and reduced aquatic weed growth. These findings align with UC Merced’s 2021 study published in Nature Sustainability.
Project Nexus serves as a test bed for multiple solar canal design solutions on both narrow‑span and wide‑span canals. This includes:
- A 115-ft-wide-span array located in Hickman, California, which covers about 38,500 ft2.
- Two 25-ft narrow-span arrays located around TID’s Ceres Main Reservoir, providing a combined 40,500 ft2 of solar shade.
- A vertical array system, featuring portrait-mounted units situated along the canal banks, further explores deployment versatility on canal embankments.
- Long-duration iron-flow battery storage has also been incorporated to explore energy storage use-cases.
- Solar Waves, a prototype retractable rail system designed for narrow span coverage, currently undergoing design field trials.
With 4,000 miles of open canals, California is uniquely positioned to explore the deployment of solar arrays over canals. By bringing a dual-purpose mindset to existing utility corridors, Project Nexus will provide real-world model data that public utilities and policymakers can use to inform future climate-forward solutions. Project Nexus seeks to show that solar over canals can help support the state’s goals of achieving 100% clean energy by 2045 and do so while conserving land use and reducing water evaporation.
“I’m proud of California for continuing to lead with innovative, outside-the-box solutions to our climate crisis — including this first-of-its-kind solar-covered canal in the Central Valley,” said California Gov. Gavin Newsom. “We remain committed to investing in clean energy and developing cutting-edge technologies to address climate and water challenges. California is showing the world what’s possible when innovation meets action.”
