California Covers Canals With Solar Panels to Combat Drought and Produce Clean Energy

California manages a massive network of canals spanning nearly 4,000 miles in total, supplying water throughout the state. With promising new prospects on the riverbank, these canals could become a source of renewable power for the state. Project Nexus, a pilot initiative funded by California’s government in partnership with Solar AquaGrid, the Turlock Irrigation District, and researchers from the University of California, Merced, aims to attempt this initiative. This first-of-its-kind U.S. demonstration aims to test the economic and technical feasibility of such a project. They plan to install over 8,500 feet of solar panels over 3 canals to test its feasibility. Through installing solar panels above working canals, the initiative aims to combine energy generation with water management.

Linking Clean Energy with Water Conservation

Primarily, this private-public-academic partnership was established to address California’s climate crisis and drought. The canopies of solar panels installed covering the canals offer a myriad of benefits. Beyond generating clean energy, they directly reduce water evaporation by absorbing sunlight that would otherwise cause water evaporation. Conserving water is especially important in drought-prone California.

The Project Nexus study estimates that widespread solar canal installation could save 63 billion gallons of water every year. This would be enough to serve 2 million residents a year. The shade canopy also discourages the growth of toxic algal blooms by blocking sunlight. This subsequently helps maintain higher water quality. Additionally, the cooling effect of water below increases panel efficiency, since cooler solar cells generate more electricity.

Solar Canals and Energy Production Potential

The energy generation potential of Project Nexus is significant and not to be understated. They estimate this project could be poised as a major source of renewable electricity. If rolled out statewide, researchers project up to 13 gigawatts (GW) of clean energy capacity per year. That output would provide more than 50% of the new renewable energy development California needs to meet the state’s climate and energy goals. This approach could also alleviate California’s exorbitant energy costs for transferring water across vast distances. Water pumping across these distances currently accounts for about 12% of the state’s total electricity demand.

Battery Storage and Grid Efficiency

Project Nexus also plans to test the integration of battery storage alongside canal-mounted panels. Storing the panels’ renewable energy locally could help reduce load during peak demand. It can also contribute to bolstering system resilience during extreme weather events. Moreso, having local storage cuts the cost of long-distance energy transfers. Inside Energy reported that between 1990 and 2013, costly energy transmission accounted for 2.2% to 13% of electricity between the plant and the household.

California has successfully connected battery storage to utility-scale grids to prevent blackouts. By connecting solar canals to local communities, California could both save money and expand energy accessibility for low-income households. Low-income households and those in marginalized communities face higher electricity cost burdens due to less energy-efficient housing and lower incomes.

Reducing Land Conflicts in Renewable Development

Traditional solar farms have been a point of contention between farmers, conservationists, and clean energy proponents. This is due to traditional solar farms having a large land footprint. Conventional solar farms require around 10 acres per megawatt of capacity, only enough to power an average U.S. household for just over a month.

Large installations in the Mojave Desert, for example, have sparked conflicts with conservationists worried about ecological damage. Solar canals avoid this issue entirely by using already-developed environments. This reduces strain on ecosystems and sidesteps contentious debates over land use, while still expanding solar capacity in a resource-efficient way.

Preserving Ecosystems and Agricultural Space

A major benefit of Project Nexus is its potential to mitigate damage to the environment and ecosystems. Solar canals circumvent these risks by repurposing existing infrastructure, incorporating technology and the landscape. Researchers estimate that California could preserve 80,000 acres of farmland and natural landscapes by adopting solar canals instead of building ground-based solar projects. This model reduces agricultural disruption while also easing tensions with Indigenous communities and farmers often opposed to projects competing for land.

Costs, Challenges, and Long-Term Benefits

While Project Nexus solar canals show promise, installation and maintenance of the panels present engineering and financial challenges. Panels installed over water must withstand higher humidity and require reinforced galvanized steel structures, raising construction costs. Maintenance is also more complex compared to traditional ground installations and would require training workers, adding to the financial burden. However, research in Nature Sustainability found that the long-term benefits exceed the added costs, including water savings, higher efficiency, and preserved land resources. By reducing evaporation and doubling infrastructure use, solar canals could become a cost-effective and environmentally sound solution for California’s resource challenges.

The Indian Model of Solar Canals

Although California is pioneering canal-based solar in the U.S., India has operated solar canal projects since 2014. The state of Gujarat launched installations to address high land prices while improving water efficiency. Beyond reducing evaporation, panels improved water quality by suppressing algal growth. This outcome is particularly relevant since toxic algal blooms cost California nearly $53 million between 2010 and 2020. India’s development, successes, and shortcomings have helped inform its U.S. counterparts and demonstrate that solar canals are viable long-term climate and agricultural solutions.

Policy, Partnerships, and the Road Ahead

Project Nexus showcases the value of public-private partnerships in scaling innovation. Federal policy also supports canal-based solar. The Infrastructure Investment and Jobs Act provides $8.3 billion for western water infrastructure and $60 million for solar energy innovation. Such funding could accelerate deployment beyond pilot programs. If implemented with thorough consideration, solar canals could become a climate solution with overlapping benefits.