The Benefits of Covering Canals With Solar Panels

A new study published in Nature Sustainability outlines the potential benefits of covering California's canals with solar panels, reports Matt Simon in High Country News. The study's results show that installing solar panels over 4,000 miles of California's waterways "would save 63 billion gallons of water from evaporating each year" and "provide 13 gigawatts of renewable power annually, about half of the new capacity the state needs to meet its decarbonization goals by the year 2030." 

Doubling up on uses for the canals would provide a convenient solution for solar installations that would otherwise require the disturbance of natural habitats or farmland. Michael Kiparsky, director of the Wheeler Water Institute at the UC Berkeley School of Law, likens the idea to placing rooftop solar panels on a suburban home. "You’re taking something that's already been altered by human activity and doubling up on the benefits it provides."

Environmental engineer Brandi McKuin, lead author on the paper, said that "by covering canals with solar panels, we can reduce evaporation and avoid disturbing natural and working lands, while providing renewable energy and other co-benefits." The study's authors "also took into account the human benefits of such a project, which are more nebulous. For example, many farmers pump their water with diesel generators. If solar panels provided that energy instead, that could cut local emissions, thus improving air quality."

"Solar-paneling California’s canals could also prepare the state for the widespread adoption of electric cars. The California Aqueduct runs right along Interstate 5, the major artery carrying traffic between the northern and southern halves of the state. Where there are now gas stations dotted along the way, in the future there might be car-charging stations that draw power from the nearby aqueduct."

The study's authors recommend a demonstration project to evaluate the costs, benefits, and potential challenges associated with a full-scale implementation of the concept.