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Biomimicry: Could Solar Panels Of The Future Look More Like Butterfly Wings?

Biomimicry: Could Solar Panels Of The Future Look More Like Butterfly Wings?

The reflective structure of butterfly wings could be useful in designing coatings that weigh less and are more efficient than the ones used on solar concentrators at Africa’s largest solar farm, according to a report in the Daily Maverick.

Solar energy is popular as a sustainable renewable energy source in many part of the world. South Africa’s Jasper Solar Energy Project in the Karoo is the largest solar farm in Africa with 96 megawatts. To harvest the sun’s energy, it relies on arrays of solar panels that are heavy and expensive to install.

Solar concentrators – mirrors or other reflective material – direct sunlight onto photovoltaic cells, where the light is converted into electricity. Solar concentrators reduce the cost of the overall operation by decreasing the required area of photovoltaic material. Jasper has more than 1,000 tracking mirrors for this purpose,  DailyMaverick reports.

The way butterflies angle their wings to optimize reflectivity is not new to solar farms: the V-trough solar concentrator has been around for decades. But the  lightness and reflectivity of large white butterfly wings are inspiring researchers anew.

Biomimicry is an approach to innovation that seeks sustainable solutions to human challenges by emulating nature’s time-tested patterns and strategies, according to Biomimicry.org. The goal is to create products, processes, and policies—new ways of living—that are well adapted to life on Earth in the long run.

Researchers at the University of Exeter’s Environment and Sustainability Institute are trying to mimic butterfly wings to create super lightweight solar concentrators, according to DailyMaverick.

The research team removed wings from large white butterflies and attached them to 1-centimeter-by-1-centimeter solar cells. Reflective film tape cut in the same shape as the wings was used and measured for a comparison.

Researchers found that the winged solar cells increased output by 42 percent, with a sunlight concentration effect of 1.3 times. The wings turned out to be less reflective than the reflective tape, but the wings had a power-to-weight ratio 17 times higher than the tape. Researchers speculate that the shape of the wings might be partly responsible for the lower reflectance, rather than the material itself.

Butterflies owe their reflectance partly to a chemical compound called pterin and the unique way it is arranged in the scale cells of their wings, DailyMaverick reports. Scientists believe the way the cells tilt helps to reflect light. Microstructures have been introduced in some solar panels for the same purpose.

The cost advantages that such a super-lightweight material might offer is striking. The challenge will be actually making it.

Prof. Tapas Mallick, who was part of the the research team told DailyMaverick, “We are currently looking into the manufacturing process and we believe it will be a cheap and low-cost process but we don’t have the engineering method to verify it at the current stage. Currently reflective films are very cheap to manufacture.”