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Capturing Solar Power With Antennae
necro81 writes "Researchers at the University of Missouri and the Idaho National Laboratory have demonstrated a new method of capturing solar power. Rather than using semiconductors to capture photons of sunlight, they fabricated small coiled antennae (several um square) that resonate with the wave nature of light. The antennae are tuned towards midrange infrared light (5-10 um), which is abundant on our cozy-warm Earth — even at night. They also demonstrated a way to imprint these coils on a substrate, like how CDs or vinyl records are produced, but could be scaled to roll-to-roll mass production. The usual caveat applies: it may be 5-10 years until this could hit the market."
It will still be 5-10 years away.
SJW: Someone who has run out of real oppression, and has to fake it.
Antennae are for bugs.
Haida Manga
The summary fails to mention the most important advancement here: 90%+ efficiency. That's a game-changer for solar power.
"When information is power, privacy is freedom" - Jah-Wren Ryel
Phrenologically speaking, your entire post is really lumpy. From a cooking standpoint, your pot is cracked. And scientifically speaking... well, why bring science into it now?
I've fallen off your lawn, and I can't get up.
Don Lancaster described this process years ago. The trick is the tiny diode at the bottom of the antenna to turn the AC into DC. It has to handle 400 - 800 THz. Plausible, but difficult. 5-10 years really means they have no idea when they'd be able to produce this in industrial quantities.
All ideas^H^H^H^H^Hprocesses in this post are Patent Pending. (as well as the process of patenting all postings)
Amiga fanboys come in second only to Tesla fanboys.
It's 2011.
Tesla's dead.
--
BMO
This is, of course, utterly useless for harvesting power from ambient thermal radiation. Even if you can make a diode that's remotely capable of rectifying current at high enough frequencies, the diode has to be kept colder than the source of the radiation. It's the electrical analog of a Brownian ratchet.
Picking up a bit of the IR tail that conventional photovoltaics don't catch? Maybe, but there isn't very much power down there even if you got the efficiency usefully high. Turning ambient heat into usable energy? Sorry, no.
Parent is successfully trolling the shit out of everyone.
"When information is power, privacy is freedom" - Jah-Wren Ryel
The newsworthiness is that instead of only 250 million nantennas on one small square like in that INL page, these guys replicated a design onto an "8 inch round silicon wafer" with 10 billion antenna elements. And they did it with high detail and little loss between the "master print" and the copy.
What are they using to rectify the signal to convert to DC?
Unobtainum diodes. They don't actually know how to do that.
Terahertz diodes do exist. Low-cost, high-efficiency, integrated terahertz diodes, no. But as work proceeds on terahertz electronics, someone may solve that problem. Each nanoantenna needs its own nanodiode, so the diodes have to be fabricated on the substrate with the antenna, which complicates the fab problem. The enthusiasm about roll-to-roll low cost fabrication in the article is premature. We'll probably see this working first on a wafer, and it may not be cheap.
Even if it's expensive, there's an initial market for satellite power panels. The performance improvement would be worth it.
The simple answer is that electronics aren't instant. Every single wire and component in any device you can build actually acts like a resistor, capacitor, and inductor. The combination of these effects means that when you, say, apply a voltage to a wire, it takes some tiny amount of time to "charge up". Even with the gigahertz frequencies used in processors, things have to be specifically built (and be tiny) to work with these charge times. If you try and do anything with *terahertz* frequencies? Even a micrometer of wire won't be "charged' before the wave goes negative, at which point it discharges... and you wind up with an average of zero volts.
TL;DR: Until we have wire made out of superconductor, frequencies that high simply can't be transfered through circuits.
The individual nantennas can absorb close to 90 percent of the available in-band energy.
Which is good for communications, where you want to exclude all but the target band. It could even work for power, providing the light source is a laser. But resonance methods aren't very good for capturing energy from broad spectrum sources like the sun.
I predict that this technique will never gain traction for solar energy. However, it might replace photodiodes for fiber optic communications.
This is the problem with solar power, it's mostly home owners who are buying them and the systems cost so much it takes decades to break even (if purely doing it for cost reasons, not CO2).
So once a better technology comes along you have to junk the old tech and you may never break even.
Hello 1978, welcome to 2011 where panels pay for themselves within 4 years, have a lifespan of 20+ years, and are significantly cheaper to produce and use less-rare components.
Antennae are for bugs.
Funny you should mention that.
Apparently insects have similar antenna systems in their antennae to detect pheromones by their infrared signature. Also electret excitation structures attached other antenna structures to emit tuned infrared when pumped by grooming.
Here's one reference.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way