A creative solution to water scarcity and land use is taking shape in the northern San Joaquin Valley – with hopes that this first-in-California concept will spread to the rest of the state.
What started as a study by UC Merced researchers in 2021 has become a reality in Stanislaus County canals. On Wednesday regional and state officials, farmers, scientists, students, business leaders and more were invited to tour the first proof-of-concept sites for an innovative project to place solar panels over irrigation canals.
Called Project Nexus, the idea was to study how the solar panels could generate carbon-free energy while at the same time reducing water evaporation and algae growth. Spearheaded by municipal water agency Turlock Irrigation District, the initiative includes a completed site in Hickman, about 45-minutes east of Modesto, and a smaller site in Ceres.
At the event, the research team joined several partners to announce the next steps to understanding the cost of implementing the project at other sites along TID’s roughly 250 miles of canals. The agency serves southern parts of Stanislaus County, starting in Ceres, and northern areas of Merced County, stretching through Hilmar and Delhi.
California Natural Resources Agency Secretary Wade Crowfoot said the findings from Project Nexus could have exciting applications across the state, and beyond.
“I think what’s most hopeful about this project is not what it will do for this region or for TID, because, after all, it’s at pilot scale, but what we can learn from this project,” he said.
California’s water scarcity has global consequences, from food distribution to tourism – so it’s no wonder that the pioneering project has received so much attention. If scalable, the impacts would have positive impacts on nearly every sector of the state’s economy.
In 2020, Gov. Gavin Newsom passed executive order N-82-20, which set a goal to conserve 30% of the state’s land and coastal waters by 2030.
“We really can’t pass up any opportunity to find new ways of using our existing infrastructure,” John Yarbrough, deputy director of the California Department of Water Resources’ State Water Project said on Wednesday.
The Valley pilot program placing solar panels over canals is only the second in the nation; Arizona has a similar project that launched in 2023.
The road from study to reality ran through Sacramento, after Newsom saw the UC Merced study six years ago and texted Crowfoot – urging him to find a way to support the idea. That resulted in a $20 million state grant to build the pilot project, in partnership with TID, UC Merced and Solar Aquagrid, a consulting company.
When initially looking for municipalities across the state to partner with, Crowfoot said TID was prepared to take on the project. The water agency was the first irrigation district in the state, so its leadership is vocal about bringing new innovative ways to keep the water flowing to customers in rural areas, he said.
So far, the concept has met with approvals for some of the region’s toughest water usage critics – farmers. TID board member Michael Frantz said, to his surprise, even his grouchiest customers have voiced their support of the solar panel project.
The pilot has two locations.
The first is a “wide-span” solar covering in Hickman that covers a 115 foot-wide canal, and stretches 300 feet and runs through the Dave Wilson Nursery. With 14 concrete foundations and 1,360 solar panels, construction took seven months to complete in August 2025.
In March 2025, TID began construction of its “narrow-span” coverings across the kind of slimmer canal that resembles the majority of the irrigation waterways across the district. The narrow solar covering spans 20-feet across and 1,380 linear feet.
Brad Cohen, general manager of TID says the two current sites will be key in scaling the idea.
“As soon as we get the net cost, I think our plan is we’re already looking at where, if this could work somewhere else but very I think they’re going to be focused developments,” he said.
Between the two sites, researchers have been able to study the results of evaporation and algae buildup over the course of a full irrigation season.
The initial UC Merced study looked at similar projects in Gujarat, India and Arizona. Valley researchers have been analysing the data from their sites. UC Merced Chancellor Juan Sánchez Muñoz said this kind of work is top of mind for people in all types of sectors.
“It’s not just what happens in Turlock or in the Central Valley, but the kind of promises given to people in other parts of our country, this kind of innovation doesn’t happen in isolation,” he said.
Over the course of the irrigation season, UC Merced researcher Brandi McKuin said the results they have seen so far show 50% to 70% reduction in evaporation under the panels, and about 85% reduction in aquatic weed growth.
Now that they have these figures, McKuin’s team can begin calculating how much money the coverings can save TID and its customers on canal cleanings and maintenance and compare it to the cost of installation and upkeep.
UC Merced is among seven other universities participating in the California Solar Canal Initiative, which hopes to fast-track operational solar panel canal coverings across the state, in line with California’s goals for carbon neutrality by 2045.
There is more than enough work to share, and UC Merced students have the rare opportunity to contribute to a project that shoulders so many expectations.
“There’s a lot of different research opportunities, and a lot of them are hypothetical,” McKuin said about the environmental engineering field, ”but this is one where there’s a real field element so they can come out.”
She and UC Merced colleague Roger Bales led the initial research project in 2021. McKuin now works alongside 10 other researchers and several undergraduate students at the university, like Grant Simon and Indalecio Martinez.
Simon and Martinez are helping the team find the true cost of the project, and hope to see it can be replicated statewide. Simon was impressed at how quickly the project was installed.
In no time, he said he was conducting fluid simulations for the team and looks forward to learning more in the next irrigation cycle.
“I feel like everyone has pride in this project,” said Martinez, a third-year mechanical engineering student. “We all want to see it implemented, and the global attention just kind of fuels the motivation.”