'Solar Canals' Could Save 63 Billion Gallons of Water Annually in California
With approximately 4,000 miles (6,437 km) of canals transporting water throughout California, the state has plenty of real estate on which to build solar panel infrastructure, a report by Popular Science explains.
It turns out that fitting panels above the waterways using suspension cables also provides a surprisingly powerful benefit for the canals themselves.
Researchers from the University of California Merced and University of California Santa Cruz used simulations to assess the economic viability of building a "solar canal" network in the state by utilizing one of the world's largest water systems, which supplies over 27 million citizens with vital water resources.
Their new study, published in Nature, may lead the way to California's canals being fitted with solar panels, doubling them up as drinking water streams and renewable energy farms. What's more, the research shows that this development would help the canals to save an enormous amount of water.
The researchers found that, aside from providing solar energy, the shade from solar panels would prevent evaporation, saving upwards of 63 billion gallons of water per year in the state.
"We were surprised by the significant evaporation savings, which we project to be as much as 82%," Dr. Brandi McKuin, lead author of the study explained in a press statement. "That amount of water can make a significant difference in water-short regions."
McKuin also said that the shade from the solar panels can reduce the growth of aquatic weeds, leading to lower maintenance costs for operators.
Water saving and solar panel cooling
Of course, the solar panels wouldn't prevent all evaporation. The evaporation that does occur, however, has the added benefit of cooling the solar panels above the waterway, making them more efficient at converting sunlight to electricity.
Though such circular benefits may make the proposition of a wide-scale solar panel canal project in the state of California — which is often struck by drought — seem like a no-brainer, several questions do still remain.
The researchers' study, for example, doesn't calculate how much energy such a network would generate, nor the cost of building such a large infrastructure.
The closest equivalent today is found in Gujarat, India, where solar panels covering a stretch of 750m of a canal cost over $18 million to build in 2015.
In Singapore, an island-state with little room for expansion, the government has started installing floating solar panels out at sea and in lakes in a bid to save valuable space on land for other purposes — another benefit also exhibited by the California solar panel canal proposition.