New Study Shows Promising Results for “Solar Canals” in California, Advancing Renewable Energy and Water Conservation

The context of cooperation with UC Water and the Sierra Nevada Research Institute at UC Merced, scientists from UC Santa Cruz have released an investigation that suggests that encompassing California’s 6,350 km network of public water shipment canals with photovoltaic panels could be a financially viable way to advance both renewable energy sources and water conservation.

The creation of “solar canals” has gained momentum across the globe as climate change increases the risk of drought in many regions. In order to prevent water loss due to evaporation, photovoltaic panels can shade waterways. Some solar panel types also work better when shaded by canals because the cooler air prevents them from overheating.

Although several configurations have been technologically usefully tested in India through pilot projects, none have yet been widely used. The world’s largest water transportation network is the network of canals in the Golden State, which also faces an impending drought and a tight timetable for switching to green energy sources. Solar waterways can address both issues, but arguing for their implementation in California requires weighing the potential benefits. The researchers’ goal in their article, which was published by Sustainability naturally, was precisely that.

According to Brandi McKuin, primary author of the recent study and a postdoctoral environmental scientist at UC Santa Cruz, covering canals with photovoltaic panels provides logical because it preserves water while generating renewable energy. Detail is where the demon is at. The crucial issue, according to Brandi McKuin, was whether the framework for extending the waterways would prove prohibitively expensive.

Steel beams or suspended cables, both of which are much more expensive to construct than conventional support structures for ground-mounted photovoltaic panels, are frequently used to support solar panels that cross canals. In contrast, a techno-economic analysis headed by McKuin showed how the advantages of solar canals combine to outweigh the costs for cable-supported installations. Solar canals supported by cables had a 20–50% higher net present value, suggesting an increased financial return.

In alongside advantages like improved photovoltaic panel performance and decreased evaporation losses, shade from photovoltaic panels may help in preventing the development of weeds in the water, which is an expensive issue for canal maintenance. Additionally, costs associated with property use can be avoided by installing solar panels over existing canal sites. Representatives of the research team hope that the additional tangible assessment of these advantages provided by the new paper will prompt field tests of solar canals in California in future years.

According to Roger Bales, a co-author on the paper and a professor of mechanical engineering at UC Merced, former director of the Sierra Nevada Research Study Institute, and the head at UC Water, this research is crucial for encouraging financial investments to produce energy from renewable sources while also conserving water.

The bales joined the initial team that formed in 2016 when the idea was developed in collaboration with UC Solar and UC Water by the San Francisco-based social impact company Citizen Company. From there, UC Merced and UC Santa Cruz began working together on the study.

Leading author Brandi McKuin began working on the project while completing her doctorate at Merced. She then continued with help from senior author Elliott Campbell, a professor at UC Santa Cruz, the Stephen R. Gliessman Presidential Chair in Water Resources and Food Solutions, and another Merced native. The idea was proposed by Tapan Pathak, an academic, and graduate students Andrew Zumkehr, Jenny Ta, and Joshua Viers of UC Merced.

In order to simulate and compare dissipation rates at canal locations throughout the state with and without shade from photovoltaic panels, Zumkehr oversaw a challenging hydrological study that used information from satellites, climate models, and automated weather stations. The financial benefits of reduced condensation were then calculated by McKuin using these details in her evaluation.

Solar canals became economically viable in the end, as opposed to benefits from decreased dissipation alone, because of the cost reductions of many consolidated benefits. The study also points out that the benefits of installing solar waterways may last longer than just short-term financial gains. In California’s Central Valley, for instance, every megawatt of solar energy produced by solar canals has the potential to take the place of 15 to 20 diesel irrigation pumps, lowering air pollution in an area with some of the worst environmental conditions in the country.

Elliott Campbell, a senior writer, adds that the breadth of advantages the report acknowledges is a crucial lesson in and of itself. He views the research as providing a clear picture of the connections between urgent global issues including air pollution, energy use, and water conservation, in addition to an analysis of solar canals.

In reality, according to Campbell, there are some special benefits when combining energy with water. In some instances, it facilitates a smoother transition to much better ways of producing electricity and conserving fluid, according to Campbell.

Reference: “Energy and water co-benefits from covering canals with solar panels” by Brandi McKuin, Andrew Zumkehr, Jenny Ta, Roger Bales, Joshua H. Viers, Tapan Pathak and J. Elliott Campbell, 18 March 2021, Nature Sustainability.
DOI: 10.1038/s41893-021-00693-8