Image Courtesy: Solar Aquagrid
A pilot project in California has shown that installing solar panels over irrigation canals can significantly reduce water evaporation and algae growth, while generating clean electricity at the same time. The results point to a dual use infrastructure model that could be particularly useful in water stressed agricultural regions.
The project, developed through a partnership involving the California Department of Water Resources, Turlock Irrigation District, Solar AquaGrid, and University of California, Merced, tested a 1.6 megawatt solar installation built directly above active canals. Early findings were published following a full irrigation season, as reported by pv magazine.
Measurements from the pilot show that covering canals with solar panels reduced water evaporation by between 50 percent and 70 percent. At the same time, algae growth dropped by around 85 percent. Both outcomes have practical implications for water management, including lower maintenance costs and improved water quality.
The concept works by shading the canal surface, which limits direct sunlight exposure. Reduced sunlight lowers water temperatures and slows down evaporation. It also restricts the conditions needed for algae and aquatic weeds to grow, helping keep canals clearer.
Beyond water savings, the system also generates renewable electricity without requiring additional land. This is particularly relevant in regions like California’s Central Valley, where agricultural land is valuable and large scale solar installations can compete with farming.
The pilot tested multiple structural designs to assess flexibility across different canal types. These included large spanning systems over wide canals, smaller installations for narrow channels, and even vertical panels along canal edges. A battery storage system was also integrated at one site to evaluate energy storage alongside generation.
Researchers estimate that scaling this approach could have a substantial impact. Covering around 4,000 kilometers of canals in California alone could save tens of billions of gallons of water annually, enough to support large scale agricultural use or supply millions of households.
The project also highlights a broader trend toward combining infrastructure functions. Instead of treating water systems and energy systems separately, this approach integrates both into a single platform, improving overall efficiency.
While further testing is needed to assess long term durability and costs, the early data suggests that canal based solar installations could become a viable option for regions facing both water scarcity and energy demand.
