aqueducts

There has been growing interest in installing solar panels on top of reservoirs to make use of the available space to make electricity and reduce evaporation. There has been far less interest in installing solar on canals and aqueducts. But that is changing and a new project in California is part of that change.

A study by the University of California, Merced estimates that 63 billion gallons of water would be saved by covering California’s 4,000 miles of canals with solar panels. All that installed solar would generate a significant amount of electricity.

The idea is going to be tested in the Turlock Irrigation District in Central California with Project Nexus, which is the installation of solar panels over 1.8 miles of canals that are between 20 and 110 feet wide. The panels will sit between 5 and 15 feet off the ground. UC Merced researchers will study impacts ranging from evaporation to water quality and use the results to make recommendations with respect to wider use of the technology.

California isn’t the first place to put solar on a canal. India pioneered it on one of the largest irrigation projects in the world. The Sardar Sarovar dam and canal project brings water to hundreds of thousands of villages in the dry, arid region of India’s Gujarat State.

Meanwhile, the Gila River Indian Community in Arizona received funding from the Bipartisan Infrastructure Law to install solar panels on their canals in an effort to save water and reduce stress on the struggling Colorado River.

The world of water infrastructure does not embrace change easily but covering canals with solar panels is an idea whose time may have come.

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Solar panels on water canals seem like a no-brainer. So why aren’t they widespread?

Photo, posted December 11, 2005, courtesy of Dave Parker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

California’s network of almost 4,000 miles of aqueducts is the world’s largest water conveyance system. It serves the state’s Central Valley which produces a quarter of America’s food. About 20% of the nation’s groundwater demand is pumped from Central Valley aquifers.

A recent study by the University of California Santa Cruz and UC Merced has determined that covering these aqueducts with solar panels could be an economically feasible way to advance both renewable energy and water conservation. California’s aqueducts might more properly be called canals because they are located at ground level.

The concept of solar canals has been gaining increasing interest around the world as the changing climate leads to more droughts in many regions. Placing solar panels above the canals can shade them to help prevent water loss through evaporation. In addition, some types of solar panels can work better situated over canals because the cooler environment improves their operation. In addition to the increased solar panel output and the water evaporation savings, shade from solar panels could help control the growth of aquatic weeds, which are a costly canal maintenance issue.

Spanning canals with solar panels can be accomplished either by using steel trusses or suspension cables, either of which is more expensive to build than ordinary ground-mounted solar panel supports. But the research study showed how the benefits of solar canals combine to outweigh the added costs for cable-supported installations.

Apart from the economic benefits of a solar canal system, producing solar energy in the canal system could eliminate the use of 15-20 diesel-powered irrigation pumps, helping to reduce air pollution in a region with some of the nation’s worst air quality.

Solar canals could be a real winner.

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New analysis shows potential for ‘solar canals’ in California

Photo, posted July 23, 2015, courtesy of Lance Cheung / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Panels On Canals | Earth Wise

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The Potential For Solar Canals In California | Earth Wise

California’s network of almost 4,000 miles of aqueducts is the world’s largest water conveyance system. It serves the state’s Central Valley which produces a quarter of America’s food. About 20% of the nation’s groundwater demand is pumped from Central Valley aquifers.

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