Moth Eyes May Hold Secret to Better Solar Panels
by Michael Graham Richard, Gatineau, Canada on 02.26.08
We've always been fascinated with what engineers and scientists are working on to make solar power more efficient. From solar balloons to nanotech "hairy" panels, there are lots of promising developments out there.
Today, lets look at a new approach. It's kind of similar to the "hairy" solar panel mentioned above, but this time the inspiration comes from the natural world (aka biomimicry), more specifically from the eyes of moths.
Silicon is reflective, so a lot of light that could be turned into electricity is bounced back and lost. Anti-reflective coating is used, but its effectiveness is limited and it has downsides too. So while looking for a solution, researchers noticed that moths have very non-reflective eyes ("most likely an evolutionary defense against nocturnal predators").
Peng Jiang from the University of Florida:
Moth eyes have orderly bumps on their corneas. Jiang refers to these bumps as “nipples.” The nipples are in an array that creates a situation in which almost no reflection exists. [...]Jiang says that a method of spin coating is used to create the effect. Nanoparticles in a liquid suspension are placed on a silicon wafer, similar to those used in solar cells. As the wafer is spun, the force created distributes the nanoparticles in the liquid. A sort of mask is created that can be used as a template. Etching is used to transfer the nanoparticle structure onto the silicon wafer beneath.
But most important: in addition to being technologically easy, the process is also inexpensive. The exact opposite of the current anti-reflective coating.
The moth-eye process creates panels that reflect less than 2% of light. That's a vast improvement over the "35 to 40 percent reflection rate seen without the anti-reflection coating layers."
::Moth eyes may hold key to more efficient solar cells
See also: ::Hairy Solar Panels Could Result From Nanowire Breakthrough, ::Video: Past, Present and Future of the Solar Industry, ::CoolEarth Raises $21 Million for Solar Balloons
Photo credit: Peng Jiang
Thin film moth eye balloon solar panels with nano carbon tube bio sterling engine thermal exchange...
It's an exciting time to be an eco geek.
Scarily, I understand everything you said Alex.
I do too :)
Can't wait until solar panels are so cheap and efficient that we can just put them everywhere.. Maybe turn the extra juice into hydrogen to be then used in fuel cells when the sun isn't shining.
I love this article!
I want to learn more about solar energy and technologies in school. :)
"Can't wait until solar panels are so cheap..."
Just remember that the fact that someone can produce solar cells at a particular cost, doesn't mean you can buy them at that price. Even now some are getting production costs pretty low... it's had little effect on the selling prices in the past 5 years. In a supply constrained market, what you pay is determined by demand... what the other people are willing to pay. It could be that way for quite a while until production catches up with demand... assuming that governments keep up programs that stimulate demand.
RhapsodyInGlue, I think more and more as peak oil hits, the government will not need to do anything to stimulate demand to make Solar competitive. The other side of supply demand, if there is money to be made, there will be more suppliers.
On the other hand, I'd love to see the government spend $40 billion or so on alternative energy research, supply, infrastructure, and deployment, but I am not holding my breath.
I had read that a company in China (daystar technologies) had created a way to make solar panels without the silicon - which was touted as an advance due to the shortage of silicon that affects the solar industry (I also read that some solar companies use recycled silicon which is also environmentally an improvement from needing a new supply of silicon...). I am no expert and just someone trying to learn about and understand all this - but anyway - I wonder if there is indeed such a thing as silicon-free solar panels and if so, should we be focusing on that, or things like this very fascinating "moth-eye" concept that still employs silicon?
Hoping to learn more (and more and more...)
Remember that solar panels won't help you at all with peak oil unless you drive an electric car. It's a common psychological response to peakoil to want to put up solar panels, but it's a couple of degrees off from the problem and probably not where you should first put your money.