Eyes of moths, allowing these insects see well in the dark, have an anti-reflective coating that makes them a less reflective surfaces of nature.

This feature has been imitated by a team of Japanese scientists to create a special coating for photovoltaic cells, which increase the electrical efficiency of these systems in more than 5%.

A team of Japanese scientists has succeeded now mimic the microstructure of this coating to generate a type of film for coating solar cells or solar panels.

In tests, the researchers showed that this film can reduce the amount of light reflected by the solar panels, increase the amount of solar energy captured and, consequently, improve their energy efficiency.

In an article published in Optics Express, the magazine of the U.S. Optical Society (OSA) researchers describe how the film created improved the performance of photovoltaic modules, both in tests in laboratory and field tests conducted in Tokyo (Japan) and Phoenix (Arizona).

According to scientists, these results show that this film could increase the performance of solar cells deployed in large areas of these regions, chosen for the tests have different annual rates of sunshine (Phoenix is a hot city, which receives large amount of direct sunlight each year, while Tokyo falls annually on a high rate of diffuse solar radiation).

Specifically, the researchers estimate that the coating inspired by the sight of the moth could improve the annual efficiency of photovoltaic cells by 6% in Phoenix and 5% in Tokyo.

One of the authors of the study, the scientist at the University of Technology, Nagaoka, Japan, Noboru Yamada, said in a statement issued by OSA that “we may assume that this improvement is very small, but the efficiency of  PV systems  is the same as the rates of fuel consumption of vehicles, every bit helps. ”

In any PV module, the emitting surface reflections are an essential loss. The reason is this: When light hits a solar cell can be reflected or absorbed, but only the light that is absorbed to produce electricity, while the reflected light is lost.

Hence the importance of anti-reflective coatings in these systems: the less light it reflects a solar panel produce much electricity.

Yamada, in collaboration with scientists from Mitsubishi Rayon Co. Ltd. and Tokyo Metropolitan University, found his inspiration for this new technology a few years ago, after spending time looking for omnidirectional antireflection structure and broad wavelength nature. The eyes of the moths was the best we found.

Yamada notes that the difficulty lay in developing the technology to design a high performance process for nanoimprint of the film. This problem was finally solved by the scientist Hideki Masuda and colleagues from Mitsubishi Rayon Co. Ltd., which in future will make these coatings on a commercial scale.

Scientists are now working on improving the durability of the film created, and optimize for various types of photovoltaic cells. Furthermore, Yamada and his colleagues believe that this solution could be applied as anti-reflection coating also in windows or computer screens.

This development would be a step in the development of solar energy technology, according to a study published in 2007 by the World Energy Council, will be the 70% of energy consumed worldwide in 2100. According to reports from Greenpeace, the PV can provide electricity to two-thirds of the world population in 2030.

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