California Completes Construction of Project Nexus Solar Canal Demo

Construction is complete on Project Nexus, a one-of-a-kind solar system being built atop an irrigation canal in California.

Project Nexus, started in 2022, with completion in 2024, is a pilot project to evaluate the promise of solar over canals to produce distributed renewable power, save water, and save land by using existing canal infrastructure. The study monitors changes in water evaporation, water quality, aquatic weed growth, and canal upkeep, along with energy production and other performance measures, with on-the-ground research conducted by UC Merced. A detailed study on these results is due to be issued later this year.

Project Nexus is a public-private-academic partnership between the California Department of Water Resources (DWR), Turlock Irrigation District (TID), Solar AquaGrid, and the University of California, Merced (UC Merced) that developed and built this project over canals in California’s Central Valley.

Multiple Prototype Designs and Early Results

“TID’s 250 miles of canals of various widths and orientations have made it the ideal host for Project Nexus.. This has enabled us to construct solar arrays over narrow and wide canals, which reflects the 4,000 miles of canals in California,”

said Jordan Harris, CEO and co-founder, Solar AquaGrid.

“We have aimed at identifying and testing several prototypes to assess performance, advantages, and risks, and eventually provide a set of solutions to fulfill distinct canal operator needs.”

UC Merced study is continuing, but early findings already suggest less evaporation and aquatic weed growth. Initial results collected over one irrigation season suggest decreased evaporation and aquatic weed development in shaded channels. The results accord with a 2021 UC Merced research published in Nature Sustainability.

Project Nexus provides a test bed for many solar canal design concepts for narrow-span and wide-span canals. This comprises:

• An 115-ft-wide-span covering roughly 38,500 ft2. Located near Hickman, California.
• Two 25-ft narrow-span arrays, sited around TID’s Ceres Main Reservoir, to provide 40,500 ft2 of solar shadow.
• A vertical array system based on units placed in portrait along the canal sides is further explored for deployment variability on canal embankments.
• Long-duration iron-flow battery storage has also been integrated to study the energy storage application cases.
• Solar Waves, a prototype retractable rail system for coverage of a limited span, is in the design field testing.

Advancing California’s Renewable Energy Goals

California, with 4,000 miles of open canals, is particularly positioned to test the deployment of solar arrays over canals. Project Nexus will apply a dual-purpose mentality to existing utility corridors to generate real-world model data that public utilities and politicians can use to influence future climate-forward solutions. Project Nexus aims to demonstrate that solar over canals may contribute to the state’s objectives of 100% renewable energy by 2045, all while saving land usage and lowering water evaporation.

“I am 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’re continuing to invest in clean energy and developing cutting-edge technologies to tackle climate and water challenges. “California is showing the world what’s possible when innovation meets action.”