Here’s a Drought-Fighting Idea: Cover Canals With Solar Panels
As California battles drought and a water crisis, scientists at the University of California, Merced, propose building solar projects atop the state’s 3,946 miles of canals.
However, leaders from the Valley’s farming and solar industries say the idea will only work if the projects make “financial sense.”
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How Can Canal Solar Projects Help Fight Drought?
As the state becomes increasingly hotter and its soils drier, there must be enough water storage to last the dry seasons to supply communities with drinking water and farms with irrigation.
The UC Merced scientists conducted case studies on the benefits of placing solar panels over bodies of water such as natural lakes, reservoirs, wastewater treatment basins, and canals.
Through their studies, they found that adding solar panels to California’s canals could initially help save 63 billion gallons of water from evaporating each year.
Additionally, the water would help cool the solar panels, which would produce more energy, and combat aquatic weed growth — a problem plaguing canal maintenance.
Another potential benefit: Replacing aging diesel pumps and generators with solar arrays. This would help clean up the Valley’s notoriously unhealthy air.
Proof-of-Concept for Demonstration Project
Professor Roger Bales of UC Merced told Wired Magazine that the paper, “is not a detailed engineering design or conceptual design — it’s a feasibility study, a proof of concept for taking it to the next phase of investing in a demonstration project.”
However, he thinks the amount of electricity canal-top solar could produce would benefit the state. Former State Water Board Chair Felicia Marcus agrees with Bales.
“A significant amount of our state’s electricity bill comes from moving, treating, and heating water, so water efficiency is also energy efficiency,” Marcus said. “We need to find every way we can to use water more efficiently, including stemming evaporative loss, as we also scale up clean energy to meet the needs of the challenging century ahead under climate change.”
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Valley Leaders Says Solar Projects Must Pencil Out
“Ultimately, what it’s going to come down to, is it cost-effective with the additional structures that are needed over the top of these canal systems?” said Ryan Jacobsen, president-CEO of the Fresno County Farm Bureau.
Jacobsen says most of the large solar farm projects are on lands that have been temporarily or permanently fallowed due to water shortages.
He also adds that solar farms add a stream of income to farmers who this year struggled to produce more crops.
“Solar allows them to either rent that land to the company or be a partner in the project and utilize that longer-term steady stream of income to help diversify their portfolio,” said Jacobsen.
Mike Pickett, owner of Pickett Solar, says he doesn’t see the project taking off in the Central Valley because it doesn’t make “economic sense.”
“For example, utility-scale projects where there’s someone who’s investing in a huge solar array like you’d see off of (Highway 41) going out to Pismo — that would be the competition to someone trying to put a solar array over the top of a canal,” said Pickett. “And, there’s just no way that a project over a canal is going to be able to compete with the economics of doing it the way you see it now.”
India’s Success with Canal Solar Projects
However, in India, these types of projects have been a saving grace for small villages. One example is Gujarat, India, which didn’t have electricity until canal-top solar was installed.
According to ResearchGate, the government of Gujarat agreed to the construction of a solar plant on a canal top and created the first pilot demonstration project near Sanand, Gujarat, in 2012.
Since then, several more projects have followed, including a 100MW canal-top solar power project atop the branch canals off the Narmada River.