photo by Fort Photo via flickr
Recently we heard about research done in Spain to develop a solar material capable of using the infrared portion of the spectrum. Researchers say this material has a theoretical absorption limit of about 63%, compared to about 40% for traditional solar materials. Well, another piece of new solar research shows that by using nanoantennas it may be possible to use a much greater portion of the infrared spectrum. Keep in mind this is a long way from commercialization, but it certainly is interesting.
Flexible Sheets of Nanoantennas Could Collect Sun's Energy
Developed by the US Dept. of Energy's Idaho National Laboratory, researchers say that one day lightweight, flexible 'skins' containing billions of nanoantennas could one day be used to cover building roofs or the outside of electronic consumer products, essentially turning the entire product's surface into an energy source.These nanoantennas are "tiny gold squares or spirals set in a specially treated form of polyethylene, a material use in plastic bags" and are able to collect energy from the infrared spectrum much more efficiently than other materials.
Up to 92% of Infrared Spectrum Usable
From Science Daily:
The researchers studied the behavior of various materials -- including gold, manganese and copper -- under infrared rays and used the resulting data to build computer models of nanoantennas. They found that with the right materials, shape and size, the simulated nanoantennas could harvest up to 92 percent of the energy at infrared wavelengths.
Nanoantennas Could Also Be Used to Cool Buildings, Electronics
This ability to absorb infrared radiation is also the reason nanoantenna skins could be used as a cooling material:
Since objects give off heat as infrared rays, the nanoantennas could collect those rays and re-emit the energy at harmless wavelengths. Such a system could cool down buildings and computers without the external power source required by air conditioners and fans.
More Research Needed Before Commercialization
Don't put flexible nanoantenna material onto your shopping list anytime soon. According to researchers there other technological hurdles to clear before nanoantennas will be able to create usable electricity. One is converting the alternating current to direct current. As these nanoantennas will oscillate at trillions of times per second, to convert this into direct current a rectifier about 1,000 times smaller than current commercial designs will be needed, according to INL engineer Dale Kotter.