Solar AquaGrid, the University of California Merced, Turlock Irrigation District, and the California Department of Water Resources are winners of the 2023 Gizmodo Science Fair for innovating a way to combine clean energy with water conservation.
The Question
Would covering California’s miles of canals with solar panels help save significant amounts of water from evaporation — and generate clean energy in the process?
The Results
In 2021, researchers at University of California Merced and Santa Cruz released the results of a study commissioned by Solar AquaGrid, a development firm based out of the Bay area, finding that covering all of California’s 6,437 km of irrigation canals with solar panels could save up to 63 billion gallons of water annually — enough for the needs of 2 million people — while also generating a potentially massive influx of renewable energy. Now, a local water utility is working with the company and the university on two pilot sites that will go into operation next year as a proof-of-concept.
Why They Did It
“Covering irrigation canals with aqueducts or solar panels is not a new idea,” said Brandi McKuin, a scientist at UC Merced and the lead author of the 2021 paper. But before McKuin and her team were contacted by Solar AquaGrid, no one had yet done “a rigorous study doing a technoeconomic and engineering analysis to understand whether the idea was worth pursuing,” she said.
“We needed academic support to really understand if this is possible,” said Jordan Harris, a cofounder of Solar AquaGrid. “Solar panels are more productive over water than they are over land, so a cooler microclimate below them actually makes them work better — the economics of that are important.”
“Reimagining our existing infrastructure, our land use policies — it’s going to take an all-of-the-above approach in order for California to meet our climate goals, especially considering the sixfold buildout of renewables that we need,” said Josh Weimer, an external affairs manager at Turlock Irrigation District.
Why Solar Panels Over Canals Are a Winner
Covering canals with solar panels has been floated before, but no one had actually done the maths about the feasibility and benefits of covering California’s canals, and no irrigation district had volunteered to test out the idea. The founders of Solar AquaGrid connected with University of California Merced, which has both solar and water research centres, to conduct a feasibility study, with blockbuster results. Turlock Irrigation District, a water and electric utility, saw the results and decided to try to make the idea a reality. In 2022, Turlock Irrigation District secured a $US20 ($28) million grant from the state to build panels at two canal sites that will be proof-of-concept for the idea.
What’s Next
The two project sites are under construction and will come online next year, providing around 5 megawatts of power. Weimer stressed that rather than water conservation — which, he says, the district is able to do more efficiently through other methods — some of the other benefits, like reduced aquatic growth in the canals and added renewable energy without taking up excess land, are the most exciting for Turlock Irrigation District. The results and impacts of the pilot projects will be watched eagerly by other water and electric utilities across California.
The Team
Solar AquaGrid, a development firm; researchers at the University of California Merced, including Brandi McKuin, lead author of the initial study; the California Department of Water Resources, which is funding the project; and Turlock Irrigation District, a local water and electric utility company.