California’s Canals Are Being Covered With Solar Panels To Save Water And Generate Power

California has long been at the forefront of experimenting with bold solutions to its environmental challenges. From investing heavily in renewable energy to rethinking water management in the face of recurring drought, the state has had to innovate simply to survive. Now, one of its most pressing problems—how to conserve water while also expanding clean power—is being tackled through a surprising partnership between infrastructure and technology. The idea is straightforward but striking: cover the state’s vast network of canals with solar panels.

The pilot project, known as Project Nexus, is unfolding in the Central Valley’s Turlock Irrigation District. Here, engineers and researchers are testing whether spanning canals with solar panels can achieve multiple goals at once: reduce evaporation, curb aquatic weed growth, generate electricity, and preserve farmland that might otherwise be converted into solar fields. If successful, the concept could transform thousands of miles of waterways into corridors of renewable energy while securing precious water supplies for farms and communities.

California’s First Solar-Covered Canal Pilot

California has launched an ambitious experiment in renewable energy and water conservation: covering irrigation canals with solar panels. The project, called Project Nexus, is currently underway in Merced County, where rows of panels stretch above the Turlock Irrigation District’s canals. This pilot site spans about 1,400 linear feet, with panels angled in both southern and western directions so engineers can study which orientation produces the greatest output of electricity. Unlike large-scale solar farms that often require sacrificing farmland or open space, this approach uses infrastructure that already exists, layering new technology onto an essential water system without taking land out of agricultural production.

The initiative represents a rare blend of state investment, local utility engagement, private sector innovation, and academic research. It is the product of a collaboration among the Turlock Irrigation District, Solar AquaGrid, UC Merced, and the California Department of Water Resources. The idea traces back to research conducted by UC Merced scientist Brandi McKuin, who in 2021 published a study demonstrating that placing solar panels above canals not only generates electricity but also has direct benefits for water management. According to McKuin, shading canals reduces evaporation, prevents excess aquatic weed growth by limiting light penetration, and even improves overall water quality while cutting down on costly maintenance. Her findings laid the scientific foundation for a project that seeks to merge renewable energy production with water conservation in a state increasingly challenged by drought.

At the heart of this pilot is the question of scalability. By studying the Turlock site in detail, project leaders aim to measure not just how much electricity can be produced, but also how much water can be saved under real-world conditions. Early estimates suggest that the canal will generate roughly 1.3 gigawatt hours of electricity each year, enough to power hundreds of homes, with all of that energy staying within the district. For the irrigation district, the project serves as a test run for whether this approach could be replicated across a broader network of canals. As Josh Weimer, the district’s director of external affairs, explained, “This is truly a pilot project for us to figure out if this is something that we should be looking at other sites and other locations throughout the TID service area.”

While modest in scale, Project Nexus carries an outsized symbolic importance. It represents more than just an engineering experiment; it is a living demonstration that energy and water systems, which are often managed in isolation, can be redesigned to reinforce one another. In a state where both electricity demand and water scarcity are pressing concerns, this dual-purpose solution reflects a new kind of thinking—one where infrastructure is not just single-use but multifunctional, with overlapping benefits for communities, agriculture, and the environment.

Water Conservation and Environmental Benefits

Water scarcity is one of California’s defining challenges. The state’s canals are critical for transporting water to farms and cities, but their open-air design makes them especially vulnerable to evaporation. In a dry year, this translates into billions of gallons of lost water that never reaches the communities or agricultural lands it was intended to serve. By shading canals with solar panels, Project Nexus directly addresses this problem, slowing evaporation rates in a simple yet highly effective way. The ability to preserve more of the state’s limited water supply offers an immediate advantage in a climate where every drop increasingly matters.

The environmental gains extend beyond water retention. One persistent issue for irrigation districts is aquatic weed growth, which thrives in canals exposed to abundant sunlight. Excessive vegetation not only disrupts water flow but also requires costly maintenance to remove. With the canopy of solar panels reducing the amount of light penetrating the surface, weed growth slows considerably. This results in cleaner canals that are cheaper to manage, while also improving water quality for downstream users. These dual outcomes—reduced evaporation and reduced maintenance—highlight the broader environmental efficiency of the approach.

There is also a land-use argument that cannot be overlooked. Traditional solar farms often face criticism for occupying vast tracts of land, some of which overlaps with fertile farmland. California, as one of the nation’s top agricultural producers, faces a delicate balance between meeting its renewable energy goals and maintaining food security. By positioning solar panels over canals, the project avoids this trade-off entirely. Farmland remains available for crops, while renewable energy infrastructure finds a home on surfaces that would otherwise go unused. This approach illustrates a thoughtful alignment between the state’s environmental and agricultural priorities.

Perhaps most importantly, the integration of water and energy systems offers a model for resilience. As climate change intensifies droughts, floods, and heat waves, the ability to design infrastructure that tackles multiple challenges simultaneously becomes essential. Covering canals with solar panels doesn’t only conserve water and improve ecological health—it represents a shift in mindset toward systems that are adaptive and interconnected. In this way, Project Nexus is as much about innovation in design as it is about the measurable savings in water or maintenance costs.

Energy Potential and Grid Benefits

The renewable energy potential of canal-based solar installations is significant. At the Turlock pilot site alone, engineers expect annual generation of around 1.3 gigawatt hours, enough electricity to power hundreds of homes in the surrounding community. While this figure might seem modest, it reflects only a fraction of what could be achieved if the concept were scaled. UC Merced’s study estimated that covering all 4,000 miles of California’s canals could generate electricity sufficient to power more than 2 million homes each year, while simultaneously conserving vast quantities of water. That dual benefit underscores the magnitude of what’s at stake in this experiment.

Another advantage lies in the location of the canals themselves. Many run close to agricultural and residential areas that are already energy-intensive. By generating electricity near where it is consumed, canal-based solar can reduce the strain on long-distance transmission lines, cutting down on losses that occur when electricity travels across the grid. This decentralized energy production strengthens grid reliability, which is especially critical as California faces summer heat waves that drive spikes in energy demand. In this sense, the canals could double as distributed energy hubs that enhance the stability of the entire network.

There is also a potential cost advantage in leveraging existing canal infrastructure. Building new solar farms often requires significant investment in land acquisition, grading, and grid connections. By contrast, canals already occupy vast corridors of land, and many run alongside service roads or existing transmission infrastructure. Installing panels over these waterways could prove more cost-effective in the long term, particularly once the engineering and maintenance challenges of this pilot project are worked out. For utilities and state agencies under pressure to meet ambitious renewable energy targets, this kind of efficiency makes the concept more attractive.

Finally, the symbolic power of linking water infrastructure to clean energy production should not be underestimated. California has committed to reaching 100 percent carbon-free electricity by 2045, a goal that will require both traditional utility-scale projects and more innovative approaches. Projects like Nexus embody the latter, signaling that the path forward is not limited to vast solar deserts or wind farms alone. By embedding renewable energy directly into the fabric of existing infrastructure, the state demonstrates that climate goals can be met in creative ways that reflect the realities of land, water, and community needs.

Challenges and Considerations for Expansion

As promising as the concept is, covering canals with solar panels is not a universal solution. Not every canal is suited to support the weight and engineering demands of overhead structures. Some waterways traverse rugged or remote landscapes where construction would be technically difficult or prohibitively expensive. Others may lack the grid connections necessary to make electricity generation practical. One of the central purposes of the Turlock pilot is to study these variables and determine where canal-based solar can be applied efficiently and where it may not be feasible.

Maintenance and durability also raise important questions. Canals require regular inspection and cleaning, and adding solar structures introduces another layer of complexity. Engineers will need to consider how to access the water for routine upkeep, how to handle debris accumulation, and how the panels themselves will withstand long-term exposure to heat, dust, and moisture. The costs of maintaining both the solar arrays and the canals beneath them could affect the overall viability of the system. Pilot data will be crucial in understanding whether the combined benefits outweigh these logistical hurdles over decades of operation.

Financial considerations will play a major role as well. While the pilot project has received funding through state and partnership resources, scaling to thousands of miles of canals would demand significant investment. Policymakers, utilities, and private companies will need to assess not only the upfront capital costs but also the payback period in terms of electricity generated, water saved, and maintenance costs reduced. These calculations will determine whether the model can compete economically with other forms of renewable development, such as large ground-mounted solar farms or offshore wind.

Beyond economics and engineering, there are regulatory and jurisdictional complexities. California’s canal system spans multiple agencies and service areas, each with its own management practices and priorities. Implementing solar canopies on a large scale would require unprecedented coordination across these organizations. While the vision of canal-based solar is compelling, its real-world implementation will hinge on navigating these institutional and regulatory landscapes. This is why Project Nexus is as much about learning and adaptation as it is about immediate power generation or water savings.

A Pathway Toward Integrated Solutions

The story of Project Nexus offers more than a novel approach to renewable energy—it highlights the growing need for integrated solutions to interconnected crises. California faces rising energy demands, recurring droughts, and increasing pressure to preserve farmland, all while working to meet ambitious climate targets. Solar-covered canals represent a way of addressing these issues together rather than in isolation. By merging water and energy infrastructure, the state is beginning to explore a model where environmental, agricultural, and community needs reinforce one another instead of competing for resources.

What makes this approach particularly powerful is its adaptability. While California may be the first to test it at scale, many regions worldwide face similar challenges of water scarcity and rising electricity demand. Countries from India to parts of the Middle East could potentially replicate the concept, adapting it to their own canal systems and energy grids. If the Turlock pilot proves successful, it could become a blueprint for global innovation in how infrastructure is designed and deployed.

Yet the greatest impact of Project Nexus may not be measured in gigawatt hours or gallons of water saved, but in the way it reframes what infrastructure can be. For too long, utilities and agencies have built systems to perform a single task—move water, generate power, deliver electricity. By combining these functions, California demonstrates that infrastructure can be multi-layered, more efficient, and more resilient. In a future defined by climate uncertainty, this kind of thinking may prove indispensable.

The takeaway is clear: solving the challenges of water and energy scarcity requires creativity, collaboration, and a willingness to experiment. Project Nexus does not provide all the answers, but it sets an example of how to start asking the right questions. By reimagining what existing systems can do, California is charting a path that other states and nations may soon follow. The canals covered in solar panels are more than a technological experiment—they are a statement about the power of innovation to meet the moment.