California is pioneering a new climate-smart solution that transforms water infrastructure into dual-purpose environmental champions, tackling both water conservation and clean energy generation simultaneously. In a bold effort to address the state’s pressing water scarcity and clean energy goals, the Golden State has begun installing solar panel canopies above open irrigation canals — an approach that conserves water by reducing evaporation while harnessing renewable energy that feeds into the electrical grid. Governor of California+1

At the heart of this movement is Project Nexus, a first-of-its-kind pilot located in California’s Central Valley within the Turlock Irrigation District (TID). This initiative has drawn widespread attention as both a proof-of-concept demonstration and a real-world test of how solar technology can be integrated with existing water systems. The project, funded with $20 million in state support, is a collaboration among the TID, the California Department of Water Resources, UC Merced researchers, and Solar AquaGrid, a Bay Area technical partner. TID Water & Power+1

Construction of the solar canopies began in stages and was completed in 2025. Panels now span several sections of the canal system, including both narrower and wide-span portions that stretch over water channels between 20 and 110 feet across. These installations are not merely symbolic — they are already producing about 1.6 megawatts of clean power, a substantial contribution to local energy supply in the rural Central Valley. Western Water

But the benefits go beyond electricity. By shading the water below, the solar canopies dramatically reduce evaporation losses — a feature that carries enormous significance in drought-prone California. A published study by UC Merced found that if similar technology were deployed across the state’s roughly 4,000 miles of public water canals, it could save up to 63 billion gallons of water each year — enough to supply drinking water for about 2 million people or irrigate roughly 50,000 acres of farmland. TID Water & Power+1

The underlying science is simple yet powerful: water loses significant volume to evaporation, especially under hot sun and wind, and shading these channels with solar panels limits that loss. Simultaneously, the water underneath helps cool the solar panels, improving their efficiency by reducing heat stress — a synergistic benefit that enhances overall energy generation. Smithsonian Magazine

According to the state’s public announcement, this innovative approach aligns with California’s broader environmental goals. The solar-over-canal projects are part of efforts to push the state closer to its target of 100% clean electricity by 2045, with interim milestones such as 60% carbon-free energy by 2030. They also complement broader water resilience strategies that include expanded storage, groundwater recharge, and improved delivery systems. Governor of California

In addition to avoiding evaporation, solar canopies may improve water quality by reducing excessive weed and algae growth, which often results from direct sunlight. Reduced aquatic plant growth means lower maintenance costs for canal operators and improves water flow efficiency. This environmental advantage has already been recognized by industry observers; Project Nexus received the Edmund G. “Pat” Brown Award from the California Council for Environmental and Economic Balance for exemplifying both economic and environmental stewardship. Tin Tức UCMerced

Experts see Project Nexus as a potential template for nationwide adoption. While California currently leads the way, similar solar canal installations have been explored abroad, particularly in regions like India, and in other parts of the United States, including Arizona. These efforts highlight a growing interest in dual-use infrastructure models that make more efficient use of space, reduce environmental impact, and deliver tangible climate benefits. Smithsonian Magazine

As climate change intensifies pressures on water and energy systems, innovative solutions like solar-covered canals demonstrate a creative path forward — one that leverages existing infrastructure, enhances environmental resilience, and shows how thoughtful engineering can generate clean, renewable power and conserve precious water resources at the same time. It’s a win-win scenario for California’s communities, agriculture, and the broader fight against climate change.