Canal Solar Tests Water-Energy Tradeoffs

California’s Project Nexus is testing solar photovoltaic arrays over active irrigation canals in the Central Valley.

Early monitoring reports 50% to 70% lower evaporation and about 85% less algae or aquatic weed growth beneath covered sections, while also assessing electricity output, maintenance, water quality, and battery storage. Statewide projections suggest substantial water and power benefits, but expansion remains uncertain because canal-top systems are more expensive than land-based solar and may complicate repairs, desilting, and ecological management.