Researchers estimate that covering all of California’s canals with solar panels could add about 13 GW of solar capacity.
The California Solar Canal Initiative (CSCI) is a research project that aims to speed up solar power over canals by identifying the best places for solar panels across California’s canal infrastructure. This initiative advances through the University of Southern California Dornsife Public Exchange and joint efforts with Solar AquaGrid and multiple other universities and state agencies. A 2021 study by researchers at the University of California, Merced, and UC Santa Cruz, published in Nature Sustainability, modeled what would happen if solar panels covered California’s roughly 4,000 miles of canals. It estimated the shade could cut evaporation by up to 63 billion gallons of water a year, and the researchers have also estimated the potential solar capacity at around 13 GW. The analysis indicated that solar panel arrays over canals could offer three primary advantages: water conservation, decreased air contamination, and land conservation benefits. Because the panels would sit over existing canals, they could avoid taking farmland out of production for solar farms. The lead researcher also said the water saved would be roughly what 50,000 acres of farmland need for irrigation.The Turlock pilot project is a first test for a possible statewide rollout in California.
Project Nexus is the pilot project that tests the idea on Turlock Irrigation District canals in Stanislaus County, and its 1.6-megawatt installation was fully completed in August 2025. The State of California supports the $20 million project, which Turlock Irrigation District executes with Solar AquaGrid and UC Merced as its implementers. The pilot examines how solar-covered canals will work at this reduced scale to determine their larger-scale statewide rollout. The pilot program examines canal areas with widths of 20 feet and 110 feet, respectively. Different directions have been used to implement the solar panels to find the best orientation for achieving maximum energy output. This project has established storage facilities that assist the regional electric power system during times when solar energy output falls below requirements.Water conservation combines with environmental advantages to stand as the primary feature of solar canals.
When canals acquire solar panels as rooftop installations, they provide dual advantages in addition to power generation. The main advantage of solar canals involves saving water. The solar panels act as a shade layer that reduces evaporation, thus protecting the state’s limited water supply during its common drought seasons. The solar panels cast shade that curbs aquatic plant growth, making canal operations more efficient through lower maintenance expenses. Environmental advantages accompany the project implementation. Clean energy from solar canals could help California in its effort to meet its legal target of cutting greenhouse gas emissions 40% below 1990 levels by 2030. If solar canals were adopted widely, they could ease the pressure on farmland by offering panel sites that do not require converting agricultural land, so farms could keep producing crops.California is using the pilot to learn where solar canals make sense on a larger scale.
Project Nexus is meant to test whether solar panels could be applied more widely across California’s canal infrastructure. A UC Merced study estimated that electricity for about two million homes a year could be generated through solar panel coverage extending across the entire 4,000 miles of canals. The pilot program seeks to identify which channels will become optimal sites for solar panel installation, even though not all channels hold suitable conditions for solar panels. The project implements different tools to measure possible water conservation and power generation capacity. According to initial calculations by the project’s lead scientist, one pilot site should produce about 1.3 gigawatt hours of electricity a year. The pilot data gathered will optimize existing estimates to support the growth of this initiative. The solar canal project in California is an ambitious test of a way to combine solar power generation with water conservation. The project uses existing infrastructure to test a way of adding clean power and cutting evaporation, and the assessment of its results is still under way. Water and power officials elsewhere are watching the pilot, and its backers hope it will lead to similar projects that combine solar power generation with the protection of key resources.Editor’s note: this article was first published on April 8, 2025, and corrected on October 28, 2026 to remove inaccurate statements about the project’s location, capacity figures and expected benefits.
