‘Solar canals’ could save 63 billion gallons of water annually in California
California is turning to an innovative idea to tackle two major challenges: water shortages and clean energy needs. The solution? Solar canals — solar panels installed over the state’s existing canal systems. This promising technology could help the state save around 63 billion gallons of water annually while generating renewable electricity. Solar canals offer a smart and efficient way forward as California faces long-term droughts and rising energy demands.
Water has always been a precious resource in California. For decades, the state has dealt with frequent droughts, made worse by climate change, a growing population, and heavy agricultural use. Much of California’s water comes from snowmelt in the Sierra Nevada, but warmer temperatures are reducing snowpack levels and changing when and how water is available.
The result is growing pressure on water storage systems like reservoirs and groundwater. When water becomes scarce, it affects residents’ daily lives and causes serious problems for farmers, ecosystems, and local economies.
Solar canals are exactly what they sound like: solar panels placed directly over water canals. These structures serve two purposes. First, the panels shade the water, which helps reduce evaporation — a major issue in California’s hot and dry climate. By blocking the sun, these panels can help save billions of gallons of water that would otherwise be lost to the air.
Second, the panels capture sunlight and turn it into electricity, like traditional solar farms. They may be more efficient than regular solar panels because the water below can help cool them, allowing them to perform better in high temperatures.
The water-saving potential of solar canals is impressive. According to researchers, covering California’s major canals with solar panels could prevent the loss of up to 63 billion gallons of water each year. That’s enough to supply over 2 million people or to irrigate tens of thousands of acres of farmland.
At the same time, the solar panels could generate gigawatts of electricity—a meaningful step toward meeting California’s clean energy goals and reducing fossil fuel use.
The benefits of solar canals go beyond saving water and producing electricity. Because they are built over existing infrastructure, they don’t require new land, which is often a concern when building large solar farms. This makes solar canals a more efficient use of space, especially in a state where land use is often a source of conflict.
They may also help improve water quality. Shading the canals can slow down the growth of algae and weeds, which means the water stays cleaner and requires less maintenance. This could save money for water districts over time.
As promising as solar canals are, some hurdles still remain. Building structures over canals is more complicated than placing solar panels in open fields. Engineers must design systems that are strong enough to support the panels but still allow for maintenance and access to the water.
The initial costs are also higher than traditional solar projects. However, experts believe that the long-term savings in water, land use, and maintenance may make up for the upfront investment.
California is already testing the idea. One major project is underway in the Central Valley, where researchers are studying how solar canals perform in real-world conditions. Early results are encouraging, showing strong potential for both water savings and energy production.
If successful, these pilot programs could pave the way for larger projects across the state’s vast network of canals — over 4,000 miles in total. With support from state agencies, universities, and private investors, solar canals could soon become a key part of California’s environmental strategy.
Solar canals show how innovative thinking can help solve some of our toughest problems. Combining water conservation with clean energy offers a powerful solution to California’s water and climate challenges. As the state looks to the future, solar canals may light the way toward a more sustainable and resilient tomorrow.
