Can Solar Cut Emissions and Protect Natural Resources?
Like geometric blue veins, 4,000 miles of open canals crisscross California in a massive network of waterways, hydrating the arid southern half of the Golden State. They could soon supply electricity as well. How will the plan to install solar panels on the waterways affect residents?
Testing the Waters
California may be the first U.S. state to create a solar canal by covering its waterways with solar panels. This massive undertaking will kick off with Project Nexus, the pilot program designed to test the idea in 2023. Engineers have not started construction yet.
Project Nexus has a hefty $20 million backing from the California Department of Water Resources. The plan is to implement the project in Hickman and near Ceres, California, in the Turlock Irrigation District. Its success or failure will likely be the deciding factor in whether to add solar panels to the Los Angeles Aqueduct.
Last November, the L.A. City Council voted to examine councilmember Mitch O’Farrell’s proposal to add solar panels, citing the need to protect the aqueduct against drought-caused evaporation. The aqueduct provided around 38% of Los Angeles residents’ water supply from 2016 to 2019.
How Waterway Solar Panels Will Help
Photovoltaic panels do a lot more than just generate electricity.
In recent years, blistering heat waves have caused much of California’s water supply to vaporize. Unlike a floating solar farm, the proposed solar panels won’t sit directly on the water. Instead, they’ll form a canopy above the waterways to shade them from the sun.
Scientific modeling predicts this design will drastically reduce evaporation. A 2021 study found that covering all 4,000 miles of waterways would save over 65 billion gallons of water annually, enough to meet the residential needs of 2 million people. That’s crucial considering the ongoing drought in California.
Reducing Aquatic Weed Growth
Thanks to the Clean Water Act — which increased the number of fishable or swimmable U.S. waterways by 60% — many of the Golden State’s canals are clean enough to fish in. However, it takes considerable effort to keep it that way.
Aquatic weeds thrive in sunlit, shallow aqueducts, and their growth can choke out fish, impart a bad flavor to drinking water and impede water flow. Removing excess underwater weeds carries a high maintenance cost. Waterway solar panels would shade the canals to such a degree that many weeds simply couldn’t grow.
In Gujarat, India, which has been using solar canals for over a decade, panels suspended above waterways curb aquatic weed growth. They also free up vast amounts of usable space in a country struggling with overpopulation and limited farmland. As the only solar development of its kind in the world, India’s Canal Solar Power Project provides clues as to how California could benefit from the same technology.
Improving Solar Panel Efficiency
Solar panels function best in a specific temperature range. Above 149 degrees Fahrenheit, they become 60% less efficient on average. Placing solar canopies above cool water improves their ability to produce energy.
Providing Clean Energy
Solar panels could generate 13 gigawatts of renewable local electricity for many Californians, lowering transmission distances and costs for residents. Having such a resilient system would also shield the energy grid against extreme weather, wildfires and human errors that might cause power outages.
Since solar panels produce no emissions, installing them above the waterways would be a massive leap toward California’s goal of reducing greenhouse gas emissions by 85% by 2045. That would significantly improve air quality and human health.
Additionally, the solar panels could prevent over 80,000 acres of wildlife habitat and usable land from being converted into solar farms. Putting the panels in artificial waterways would protect vulnerable plant species that need full sun as well as prevent habitat fragmentation. It also means the state could set aside more farmland to grow nuts, vegetables and fruit.
The Future of Solar
Project Nexus will likely determine whether California moves forward with its solar canal idea. If the pilot program demonstrates that solar panels can provide clean, affordable energy and safe drinking water while preserving usable land, the state will likely proceed by installing panels above the Los Angeles Aqueduct.
If California and other states want to reach their ambitious environmental goals, they must take ambitious action. The best time to start is now.
Jane Marsh works as the founder and editor-in-chief of Environment.co where she covers environmental news and sustainable living tips.