As part of a broader research effort to conserve California’s scarce water resources, a $20-million pilot project in the state will investigate the use of solar canals as a major source of renewable energy. Known as Project Nexus, the state-funded venture is expected to demonstrate how covering canals with solar panels can reduce water delivery system costs and generate enough electricity to meet ambitious clean power goals.
Public water and electric utility Turlock Irrigation District in central California announced Feb. 8 that it has accepted state funds to provide proof of concept for the project using its utility infrastructure and will install and test the performance of solar canopies over less than 2 miles of its 250-mile canal system, using its existing electrical grid to capture energy storage from the panels.
A public-private-academic partnership that includes the district, the California Dept. of Water Resources, development firm Solar AquaGrid and the University of California-Merced, Project Nexus is expected to break ground this fall, with completion by 2024. If expanded beyond the scope of its demonstration phase, the project could serve as a low-cost template for canal systems across the country, says Josh Weimer, a district spokesperson.
“The concept of using land that we already own, right where our infrastructure is, to save cost is something that we are very interested in studying, and is really what led us to pilot this first-in-the-nation type of project,” he says.
Nexus builds upon a 2021 University of California-Merced scientific study theorizing that solar canals could save the state 63 billion gallons of water a year and generate 13GW of electricity from its roughly 4,000 miles of canals. Electricity generated is estimated to equal about one-sixth of the state’s current installed capacity.
According to the study, solar canals would also reduce water evaporation by providing shade, which would mitigate wind and improve water quality through reduce vegetative growth—decreasing canal maintenance altogether.
For the district’s open top, gravity-fed canals, there is potential to reduce major maintenance costs.
“We spend a lot of time and money to clean out our systems throughout the irrigation season because weeds get in the way and impede our ability to deliver water,” says Weimer, explaining that the district is working with AquaGrid to design a system that won't impede its ability to operate its canal system.
“So we are studying everything, the construction feasibility of the project, the quality benefits, our savings and renewable energy generation,” he says. "It’s been a great partnership so far."