Swiss stand in support of nuclear power

[GNEP]

Nah... flatulence power is the way forward

[Brian Ellis]

GNEP

There's no need to show us you're a lobbyist for the National Association of Bean Growers and the Institute for the Promotion of Jet Propulsion.

[James_D]

Nah... the easiest way is probably harness the suns energy, via frequency shifting. Directly turn light into whatever frequency you want.

Theory from MIT:

http://www.newscientist.com/news/news.jsp?id=ns99993750

James.

[Technoid]

Originally posted by James_D
Nah... the easiest way is probably harness the suns energy, via frequency shifting. Directly turn light into whatever frequency you want.

Theory from MIT:

http://www.newscientist.com/news/news.jsp?id=ns99993750

James.

That was an interesting read

[Marshmallowman]

Theory from MIT:
http://www.newscientist.com/news/news.jsp?id=ns99993750

Man that could be nobel prize winning stuff!!.

Seems like using soemthing like that you could double the efficiecy of currrent solar cells, not to mention your standard incandescent light bulb!!

Also converting normal full spectrum sun into pure infrared for heating....

I am going to keep an eye on that one

[Wombat]

Originally posted by Marshmallowman

Seems like using soemthing like that you could double the efficiecy of currrent solar cells, not to mention your standard incandescent light bulb!!

Doubtful. It takes a lot of energy to change the light. Also, how would reducing the energy of a photon increase the efficience of the cell?

[James_D]

Originally posted by Wombat
Doubtful. It takes a lot of energy to change the light. Also, how would reducing the energy of a photon increase the efficience of the cell?

Well by tuning the wide spectra light into narrow frequency, you can at least optimize the light for the photoreceptor/Solar panel.

James.

[Marshmallowman]

Thats right james the peak efficency is reasonably limited range and the fact it they say they convert with very high efficiency means it should work.

Energies(light frequencies) below a certain threshold are completly wasted in solar cells, and the higher end(bluish-uv) has so much surplus energy that is wasted in a normal solar cell and even breaks silicon bonds and degrades the cells(in amorphous silicon type cells anyway, which are the cheap ones you see in most solar gadgets)

If there stated conversion effiency are even close to what they achieve big thing are afoot.

But saying they can get close to 100% conversion efficieny is a pretty big claim...but if?!

they way I interpret that article is, that if you get uv photon which may have twice the energy say a red photon, this process would give you 2 red photons for a uv photon(vastly simplified but you get the idea)

[Brian Ellis]

Don't see it as practical for energy production purposes. In the first place, you cannot create energy by changing its frequency. By physical laws, you can only lose energy and tens of thousands of reflections will do this. And if it requires a bullet being fired at a chip, well!!! There's a helluva lot of kinetic energy in a 10 g lump of lead beetling along at 1,000 k/h just to prove a minute quantity of light has changed from white to resemble the stars and stripes?

I've little doubt that it's academically interesting but that's a far cry from increasing the efficiency of a PV cell (which has a reasonably wide bandwidth, anyway.

[Marshmallowman]

You are not creating energy, light is wave with some particle properties, you are you changing its form.
When they talk about compression, it seems to imply that get some kind of standing wave interaction occurs.

However withour reading an actual paper on it, my interpretaion could be(and proabbaly is) completly wrong.

I think I'll see if I can track down some more "scientfic" information, popular science articles tend to be very vague..

[Wombat]

Right, Brian touched on the problem, buch Marsh seems to have missed it. Yes, it is nearly 100% efficient, as in "almost all light in ends up going out." However, this does <B>not</B> take into account the energy it takes for the crystal to be kept in proper motion.

Initially, they are doing it with a bullet, destroying the crystal in the process. They are working on ways to just get sonic vibrations to do the work, but I still believe that even that approach will consume more energy than the "optimized" light would provide.

[Marshmallowman]

Not published yet...

Energetic UV has as much as 10 times the energy of light at the peak effiecny of a typical solar cell. so lets a 50 % eff you get 5 photons for one...

Photons below a certain threshold energy level normal cells would simply convert a lot of the energy to heating the cell...But if the compression thingy works then you would be able to use those energies, or design cells with lower peak effieciencis and shift the incoming down to suit.....But of course would be a LONG way down the track..

I actual did my physics honours in solid state physics, in particular light interaction on amorphous silicon substrates(as in solar cells)

[James_D]

http://www.rpii.ie/press/pr200305.htm

This is an article concerning Sellafield, and their dumping of Radioactive material to the Irish Sea. So to all living around the Irish sea. Read this..

James.

[Brian Ellis]

Whereas the conversion efficiency of a solar PV cell (which is currently - pun intended - very low, of the order of 10%) may increase when irradiated at near UV, I fail to see how converting the oscillation frequency of a "photon" to a higher frequency will create five photons, physics honours degree or not.

The article states that frequency conversion works in both directions. Does this mean that if you work from blue to red, the conversion of a photon will produce only half-a-photon or less?

[James_D]

LOL I would like to see a Half Photon..

Off Topic: Ever heard of a Laser tweaser? We use it a lot in medical practice, esp, in InVitro fertilization. Using some of the photons other properties.. Pretty phun..


James-