A Light Wave of Innovation to Advance Solar Energy

[OKIsItJustMe]

http://www.aftau.org/site/News2?page=NewsArticle&id=15507

A Light Wave of Innovation to Advance Solar Energy

Thursday, November 10, 2011

TAU researchers adapt classic antennas to harness more power from the sun

Some solar devices, like calculators, only need a small panel of solar cells to function. But supplying enough power to meet all our daily needs would require enormous solar panels. And solar-powered energy collected by panels made of silicon, a semiconductor material, is limited — contemporary panel technology can only convert approximately seven percent of optical solar waves into electric current.

Profs. Koby Scheuer, Yael Hanin and Amir Boag of Tel Aviv University's Department of Physical Electronics and its innovative new Renewable Energy Center are now developing a solar panel composed of nano-antennas instead of semiconductors. By adapting classic metallic antennas to absorb light waves at optical frequencies, a much higher conversion rate from light into useable energy could be achieved. Such efficiency, combined with a lower material cost, would mean a cost-effective way to harvest and utilize "green" energy.

…

According to Prof. Scheuer, these "old school" antennas also have greater potential for solar energy because they can collect wavelengths across a much broader spectrum of light. The solar spectrum is very broad, he explains, with UV or infrared rays ranging from ten microns to less than two hundred nanometers. No semiconductor can handle this broad a spectrum, and they absorb only a fraction of the available energy. A group of antennas, however, can be manufactured in different lengths with the same materials and process, exploiting the entire available spectrum of light.

…

The goal is not only to improve the efficiency of solar panels, but also to make the technology a viable option in terms of cost. Silicon is a relatively inexpensive semiconductor, but in order to obtain sufficient power from antennas, you need a very large panel — which becomes expensive. Green energy sources need to be evaluated not only by what they can contribute environmentally, but also the return on every dollar invested, Prof. Scheuer notes. "Our antenna is based on metal — aluminium and gold — in very small quantities. It has the potential to be more efficient and less expensive."

[Fumesucker]

1. I believe the actual term is "rectenna" so it would be a "nano rectenna"..

http://en.wikipedia.org/wiki/Rectenna

[AlecBGreen]

5. a rectenna?

isnt that what comes out of your bum after aliens probe you? :hide:

[Nihil]

7. Nah ...

... it's what happens when a fat pigeon lands badly on your TV aerial ...
:grr:

[mpgalloway]

2. The Oil Companies will just buy it and bury it. Business as usual!

I have been following and participating in start up
alternative energy inventions for 35 years.

The energy companies buy them, run them out of business,
and make sure the real ones never see the light of day.

Our so called "Energy Crisis" is completely prefabricated
to make profits for the 1%.

Believe it!

[Gregorian]

4. Those days are over. They can't bury it.

I know what you're saying. But the flood gates are open now.

Glad you've found this forum. Cheers.

[Gregorian]

3. Incredibly interesting.

This is the kind of research that is going on all over the world. I love it. Almost a magnitude in efficiency greater than what we have in standard cells.

[kentauros]

6. While it's great to see other groups studying this technology,

there's still a rather large stumbling block to harnessing this energy: converting high-frequencies down to usable electrical frequencies.

I read about this technology some years back, done at the Idaho National Laboratory, and the head researcher has talked about this problem as well as the problem of scaling the prototype up:

Q&A: Steven Novack

The Idaho National Laboratory researcher prophesies a future in which solar antennae are as easy to use as Saran Wrap—and almost as cheap.

—By Daniel Luzer
November/December 2008 Issue

>snip<

MJ: Basically the struggle you're faced with now is how to make it widely available without losing efficiency?

SN: Well yes, but we also have to come up with some new methods and some new designs to be able to actually get the electronic circuitry that will work at those high frequencies. Right now there are probably some working prototypes and designs that you can buy with 3 trillion Hz. We really need to get up to 30. And we want to do that obviously efficiently, so we're going to have to do some research in that area to get these things into a market that people are going to want to purchase.

Really, there are two challenges to this technology. The first challenge is being able to make and go from this small prototype that we've developed into a large, inexpensive, manufacturable product on flexible substraits, like plastics. And we've done a fairly good job on that. And that's why we've gotten the awards and why people are excited about this process, 'cause we've solved one of the problems. The second problem is the electronic circuitry. And we most likely will have to partner with somebody who's working in that area. But there are a lot of people working in this area. If we want to go to optical computing, for example, which is computers that operate on light versus electrons electricity, we're going to need to solve this problem.

...more at link...

[kenfrequed]

8. What intrigues me

Is that every single alternative energy technology post that gets put up here automatically has nay-sayers. In fact looking at most large media websites, message boards, and social networking sites I have noted the presence of the naysayers of wind and solar.