California will cover canals with solar panels to combat drought and climate change
Two things on California’s wish list — more water and more power — may be coming soon with a nation-first plan to cover irrigation canals with solar panels.
The project, which aims to save water by reducing evaporation from canals while generating renewable energy, is small, spanning nearly two miles of waterways in the Central Valley. However, the hope is to showcase the simple but largely unproven concept so that it catches on with agricultural and urban water providers across the state and beyond.
The California Department of Water Resources is funding the $20 million pilot program with the intent of learning where solar panels might be feasible along the state’s 4,000 miles of canals and aqueducts. California’s water transportation network is one of the largest in the world, which means great potential for the idea. The need for more water and carbon-free energy is increased by drought and a warming climate.
“Driving into Los Angeles, you see the aqueducts and you can’t help but imagine how much water is lost to evaporation,” said Jordan Harris, co-founder and CEO of Solar AquaGrid, the Marin County company that is designing and managing the demonstration project. near Turlock in Stanislaus County, about 90 miles south of Sacramento.
“We are not reinventing the wheel,” he said. “We are using existing technologies and we are just applying them in a different way. We are just making these utility corridors work harder and provide multiple benefits.”
The irrigation canal at one of the proposed Nexus Project sites in Ceres (Stanislaus County).
Carlos Ávila González, Staff Photographer / La CrónicaThe effort, called Project Nexus, is the result of a study published last year by researchers at UC Merced and UC Santa Cruz that found that viewing “solar channels” could yield real benefits. Solar AquaGrid commissioned the research.
According to the study, published in the journal “Nature Sustainability,” by covering all of the state’s water supply channels with solar panels, evaporation would decrease by up to 90%, saving about 63 billion gallons of water per year, the equivalent of what up to 3 million people use.
In terms of power generation, the authors estimate that installing arrays over the state’s canals and aqueducts would produce about 13 gigawatts of power, roughly one-sixth of California’s current capacity. The new power would help the state meet its goals of switching to carbon-free power, as well as boost supplies to help prevent the kind of grid shortages seen during last summer’s heat wave.
A rendering of solar panels installed along a canal in California’s Central Valley, an idea being brought to life at Project Nexus.
Courtesy Solar AquaGridThe study also detailed other benefits. Vast tracts of expensive new land would not be needed to generate solar power, minimizing the debate over converting farmland or virgin deserts for multitudes of panels. Solar panels on the canals would also operate more efficiently because the water would keep them cool.
Also, the water in the canals would see less algae and aquatic weed growth due to shading. Weed control is a huge and costly maintenance problem for California water agencies.
“This paper was a first estimate of whether this (idea) is worth pursuing,” said Brandi McKuin, the study’s lead author and an assistant project scientist at UC Merced. “Now we know it looks good on paper. The next step is to do a pilot test to see if some of these hypothetical benefits actually materialize.”
A small demonstration of solar troughs has been developed in India, in the states of Gujarat and Punjab, McKuin said, but the researchers want to see a larger, up-to-date test closer to home.
The Turlock Irrigation District, one of the largest providers of agricultural water in the state, volunteered its 250 miles of canals for the effort. The agency was interested not only in saving water but, since it also provides energy, in generating renewable energy.
“We are eager to prove that this concept can and will work,” said Josh Weimer, a spokesman for the district.
An aerial view of the irrigation canal in Ceres (Stanislaus County), where solar panels are scheduled to be installed over the canal.
Carlos Ávila González, Staff Photographer / La CrónicaThe district and Solar AquaGrid had hoped to begin construction of the solar troughs this year, but supply chain issues made it difficult to source the necessary transformers, Weimer said. The plan is to start early next year and conclude in 2024.
The proposal calls for the deployment of solar panels in two stretches of canals: about 500 linear feet of panels over a 110-foot-wide waterway in the Hickman community and about 8,000 linear feet of panels over a 110-foot-wide waterway in the Hickman community. 25 foot wide in the community. of Ceres. Initially, the project is expected to produce around 4 megawatts of power, roughly enough for 850 homes.
McKuin and other researchers will be monitoring the project’s performance.
However, both his research and the Nexus Project have already generated enthusiasm for the idea. The state is looking to invest in more projects, the federal government earmarked $25 million for solar troughs in the Reduce Inflation Act, and Los Angeles is studying a proposal to install panels on a city-owned aqueduct.
“From the conversations I’ve had with water agencies in California, in the US and honestly around the world, there’s a lot of interest in this,” Weimer said. “Once we start construction, we will be contacting a lot of water agencies to discuss how things are going.”
Kurtis Alexander (they/them) is a staff writer for the San Francisco Chronicle. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander