Settling snow and ice can significantly dampen the output of a solar panel, and if enough accumulates this can even cause damage or catastrophic collapse. But a transparent coating can shed everything from light snow to thick ice and ensure panels remain operating autonomously for long periods.
at the University of Michigan and his colleagues carried out an experiment from December to April at a solar farm in Alaska where temperatures can plummet to 鈭�35掳C. They left some panels uncoated and applied a coating of polymer chains in a transparent film to others, while all panels were tilted to an angle of 45 degrees.
During that period of several months, the uncoated panels had an average snow coverage of up to 59 per cent, while panels with the coating had only 28 per cent coverage. The team estimates that the panels would generate as much as 85 per cent more energy with the coating under those conditions.
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The material used in the coating was a combination of medium-chain triglycerides, which can be extracted from palm oil and coconut oil, embedded in a polyvinyl chloride. The coating could have other applications including for car windshields and covers for lidar sensors on driverless cars, and it can be applied simply with a brush as a liquid that sets solid.
The team believes that two mechanisms are at work. The coating stops snow and ice binding with the surface, which reduces friction and allows material to slide off. It also makes it possible for cracks to appear and easily propagate at the point where ice meets the panel, which makes it easier for ice to slide off in smaller chunks that have less friction rather than a large sheet.
Snow can have a density of just 0.1 grams per cubic centimetre, while heavy ice can be nine times as dense. This has made it difficult to develop a coating that works to remove everything across that spectrum until now.
鈥淭ypically, the coatings employed to shed ice work under its own weight. Because of the variation in the structure and density of snow, it can be really challenging to employ the same strategies,鈥� says Tuteja. 鈥淭he technique we鈥檝e developed is one of the first approaches that works for shedding both small and large pieces of ice. It also seems to work really well for shedding snow.鈥�
Advanced Materials Technologies
