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Where are the 70% Efficient Solar Cells?

Cliff posted more than 11 years ago | from the better-power-from-photons dept.

Science 798

VernonNemitz asks: "Back in 1984 a patent was granted for silicon chip micro rectennas, which would convert visible photons into electricity in the same way that ordinary rectennas convert microwaves into electricity, at perhaps 70% or greater efficiency. Nobody could make such solar cells back in 1984, but we certainly can today, with sizes of antennas that would capture everything from infrared to the edges of UV -- and the patent has expired. So, where are they?" Currently the most popular type of solar technology is photovoltaics, however PV technology only has an efficiency of about 7-17%. With the potential gains claimed by the technology in the cited patent, has anyone even tried to build one of these units to see if it can live up to the given promise, or at least prove to be a technology than we should be exploring?

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798 comments

Beats me (5, Funny)

dmanny (573844) | more than 11 years ago | (#5042931)

They keep me in the dark about these things :-)

Heres a company - up to 80% efficiency. (5, Interesting)

cosmosis (221542) | more than 11 years ago | (#5042999)

I have know about this company for years. Lumeloid Solutions [polar-solar.com] claims their technology is theoretically capable of efficiencies of up to 80%.

Also there was a story about 2 weeks ago, mentioning solar energy breakthrough using full-spectrum layering. Does anyone know anymore about this. I was unable to find it in Google News.

Nanotech material, once they arrive, will of course make 90% efficient material practical.

Planet P Blog [planetp.cc] - Liberty with Technology.

Apple Macintosh Solar Cells (-1, Troll)

Anonymous Coward | more than 11 years ago | (#5043080)

They have a 3% efficiency, but they charge you for 80%, and the added cost is for feeling "incredible", "awesome", and hip.

Re:Heres a company - up to 80% efficiency. (-1, Troll)

Anonymous Coward | more than 11 years ago | (#5043103)

Astroturfing nerd, how many times will you post this information in this story? What are you, the secretary at lameloid?

Re:Heres a company - up to 80% efficiency. (5, Funny)

bperkins (12056) | more than 11 years ago | (#5043151)

Nanotech material, once they arrive, will of course make 90% efficient material practical.

What kind of nanotech material are you talking about? Little nano robots that run around catching photons IN their nano baseball gloves and pitching them into nano furnaces that run nano generataors?

If you want people to take you seriously, a statement like, "nanotech materials _may_ be able to produce 90% efficient material," is more reasonable. "of course" is just silly.

Re:Heres a company - up to 80% efficiency. (4, Informative)

LHorstman (572584) | more than 11 years ago | (#5043193)

This company actually seems to be developing the very technology, or very similar, in the patent posted in the story. At This [polar-solar.com] page on the Lumeloid website, they list the technology coming from Alvin Marks, the same person listed in the patent [164.195.100.11].

Re:Heres a company - up to 80% efficiency. (2, Interesting)

lazn (202878) | more than 11 years ago | (#5043220)

Hmm, the company needs to learn some physics. (and I neet to learn how to spell)

From the website you linked:

"This high efficiency is made possible by the use of polarization, which causes absolutely no loss in the available light energy, yet organizes the light to aid its conversion to deliverable electric current."

http://www.howstuffworks.com/sunglass4.htm

"A polarized filter passes only the light that does not match its orientation. Only the part of the light wave that is not aligned with the slots in the filter can pass through. Everything else is absorbed."

It seems to me that if the filter absorbs light not in the correct orientation, then the available light energy would be decreased.

So who is right? howstuffworks.com or polar-solar.com?

==>Lazn

Rectenna? (5, Funny)

medscaper (238068) | more than 11 years ago | (#5042933)

a patent was granted for silicon chip micro rectennas,

Anyone else get a sorta shifty feeling when they look at that word and picture the consequences of such an invention?

Re:Rectenna? (3, Funny)

jtheory (626492) | more than 11 years ago | (#5043007)

Don't worry, you won't feel a thing after "utilizing an electron beam and suitably coating and doping the rectifying areas" (from the patent description).

Seriously, I wouldn't be surprised if there are a few grad students who've been toiling away on this project but can't get any funding. Or... maybe the idea just doesn't work out in practice.

We also can't overlook the fact that lots of important stuff is, well, overlooked. Any comments from anyone in the field?

Re:Rectenna? (-1, Redundant)

Anonymous Coward | more than 11 years ago | (#5043018)

i hoe south park doesnt have to pay any fees for displaying a rectenna in an episode...

Re:Rectenna? (0)

Anonymous Coward | more than 11 years ago | (#5043042)

That would explain why it is so popular with the slashbots.

Why we have to have 80%+ (5, Interesting)

cosmosis (221542) | more than 11 years ago | (#5043105)

I don't get a shift feelign at all. We are already direly close to Hubbert Peak, when oil demand starts to outstrip production. In fact Hubbert, himself an oil man, said that Hubbert Peak, even considering undiscoverd reserves (which is fairly predictable with satellite reconaissance) will come sometime between 2002-2009.

You can read about here on my website [floatingplanet.net] for more info. Some in the oil industry are thinking that peak will be hit within the next two years. This might explain our rush to invade Iraq.

Either way, as oil reserve dwindle and demand goes up, it will create a highly destabilized politic - and if you think the repression we've all been feeling lately is bad, it will only get worse... UNLESS:

We wean ourselves (QUICKLY!) off of Oil. The Hydrogen economy is just waiting in the wings. All of the technology is essentially there. The cost factors will become not only competitive, but cheaper and cleaner than oil, once we start migrating our energy infrastructure over to Hydrogen.
Lets hope this happens before we end up in some kind of nigthmarish Oil Fedual/Fascist Global New World Order.

Planet P Blog [planetp.cc] - Liberty with Technology.

Re:Rectenna? (2, Funny)

Anonymous Coward | more than 11 years ago | (#5043158)

Yes, but wouldn't it be counter-productive to put it where the sun don't shine?

Re:Rectenna? (5, Funny)

frankie (91710) | more than 11 years ago | (#5043164)

silicon chip micro rectennas
picture the consequences of such an invention?

Here's the best that Google could come up with for picturing a rectenna [google.com], but the exact image I wanted wasn't found. As demonstrated in episode 101, rectennas are powerful, but also put out a lot of heat.

Re:Rectenna? (1)

Tex Bravado (91447) | more than 11 years ago | (#5043241)

Clearly this is the technology used in all those alien abductions, so it should be no surprise that the efficiency is greater than that which we typically can achieve. I wonder if Mel Gibson or Drew Barrymore read slashdot ? Perhaps they could comment.

Goverment rebates (3, Informative)

Bellator (519329) | more than 11 years ago | (#5042936)

There are government rebates for people who use PV as well. So if anyone gets interseted, look into it. You can also find some good sources at renewables.com.

It seems someone is working on them... (5, Informative)

jobeus (639434) | more than 11 years ago | (#5042940)

There's supposedly some work being done on Berkeley for cells up to 70% efficient: http://www.scienceagogo.com/news/20021020210743dat a_trunc_sys.shtml [scienceagogo.com]

Re:It seems someone is working on them... (3, Informative)

RealAlaskan (576404) | more than 11 years ago | (#5043046)

The patent would have us etch tiny dipoles on a semiconductor: The present device differs from the prior art devices in that it utilizes a plurality of dipole antennae for absorbing light photons, ... , while the ones you refer to are modern, much improved examples of what the patent calls prior art.

They look neat. The researchers think that they'll be cheap and efficient. But where are the microarrays of silicon rectennas?

I know where they are (5, Funny)

muyuubyou (621373) | more than 11 years ago | (#5042942)

They're next to that new compression algorithm, that one claiming a 90% improvement over Huffman.

Next to the 100MPG carburators... (0)

Anonymous Coward | more than 11 years ago | (#5043213)

... that the oil companies bought to keep us guzzling gasoline!!!

Hell, 30 percent would even be nice... (2)

mudshark (19714) | more than 11 years ago | (#5042944)

...it would still represent a doubling of the current "best" and motivate me to put up some panels. Of course, I live in a sunny desert and have no excuse anyway.

Where are the 70% efficient solar cells? (2, Funny)

Pyrosophy (259529) | more than 11 years ago | (#5042954)

It is the year 2003, but where are the 70% efficient solar cells? I was promised 70% efficient solar cells. I don't see any 70% efficient solar cells. Why? Why? Why?

Re:Where are the 70% efficient solar cells? (0, Redundant)

grub (11606) | more than 11 years ago | (#5043082)


It is the year 2003, but where are the 70% efficient solar cells? I was promised 70% efficient solar cells. I don't see any 70% efficient solar cells. Why? Why? Why?

Because all the 70% efficient solar cells are in the trunk of my 2000 model Flying Car!

Re:Where are the 70% efficient solar cells? (0)

Anonymous Coward | more than 11 years ago | (#5043092)

They are out there, you just cant see them because they are 70% invisible.

Re:Where are the 70% efficient solar cells? (0, Redundant)

kent_eh (543303) | more than 11 years ago | (#5043122)

I was promised 70% efficient solar cells. I don't see any 70% efficient solar cells. Why? Why? Why?

They're in the garage beside the sky-car.
You mean you haven't recieved yours yet?

Re:Where are the 70% efficient solar cells? (0)

Anonymous Coward | more than 11 years ago | (#5043156)

Where are the transporters, warp engines, flying cars, computers that understand human speech, holodecks, and phasers, and more importantly,
where are the sliding doors that make that neat whooshing sound when they open!!!
Solar schmolar! If it can't be used as a weapon why bother.

Check out Lumeloid - up to 80% (2, Redundant)

cosmosis (221542) | more than 11 years ago | (#5042960)

Yes, I have been wondering this too. There is company I have been aware of for about 10 years, called Lumeloid Solutions [polar-solar.com], that claims that there technology can be theoretically capable of 80%. And just last week I was hearing about some full-spectrum solar cell that was capable of 70%. Does anyone know where that story went? I cannot find it throught Google News.

Of course, when nanotech material arrive, efficiencies in the 80-90% will be practical.

Planet P Blog [planetp.cc] - Liberty with Technology.

But is it real? (3, Interesting)

Fished (574624) | more than 11 years ago | (#5042963)

Looking at the patent application, I saw absolutely nothing to convince me that this idea makes any sense. I see no company, no diagrams, etc. Is it real? I'm not qualified to say.

Re:But is it real? (2)

SomeoneGotMyNick (200685) | more than 11 years ago | (#5043149)

Maybe the patent was applied for to PREVENT others from working on the idea. That way, for the time the patent is in effect, the patent owner can leisurely produce a working model and saturate the market with solar cells more efficient than anything else that's out there.

Research (5, Insightful)

crumbz (41803) | more than 11 years ago | (#5042964)

What the US needs is a Manhattan Project for alternative energy to oil. Solar, wind, geo, fusion, whatever. Something but burning simple chain hydrocarbons and because the waste product is mostly invisible, pretending it doesn't exist.

Who elected George Bush anyway?

Re:Research (4, Funny)

BabyDave (575083) | more than 11 years ago | (#5043050)

What the US needs is a Manhattan Project for alternative energy to oil.
They should threaten their enemies with windmills?

Re:Research (5, Funny)

Dr. Smeegee (41653) | more than 11 years ago | (#5043100)

> They should threaten their enemies with windmills?
Notice anyone threatening the Netherlands lately, Wisebeing?

Re:Research (1)

k3v0 (592611) | more than 11 years ago | (#5043051)

oil elected george bush... are you suprised that SUV gas mileage has only been mandated to improve 1.5 mpg?

Re:Research (1)

Desert Raven (52125) | more than 11 years ago | (#5043231)

oil elected george bush... are you suprised that SUV gas mileage has only been mandated to improve 1.5 mpg?

Absolutely! After all, Clinton and Gore mandated much higher standards than...

Oh, wait, never mind.

Re:Research (2)

Artifex (18308) | more than 11 years ago | (#5043066)

What the US needs is a Manhattan Project for alternative energy to oil. Solar, wind, geo, fusion, whatever. Something but burning simple chain hydrocarbons and because the waste product is mostly invisible, pretending it doesn't exist.


No kidding. We've used the excuse of dependence on foreign oil to barge around in the Middle East, propping up dictators and then fighting them, since before I was born.

Who elected George Bush anyway?


Some judges, really. =) I don't know how Al Gore would have handled foreign policy, but at least he'd have sounded adequately literate during his speeches.

Re:Research (0)

Anonymous Coward | more than 11 years ago | (#5043072)

Who elected George Bush anyway?

The minority.

Re:Research (0)

Anonymous Coward | more than 11 years ago | (#5043106)

In today's dollars, such a project would be very expensive, and no doubt disrupt many well established energy corporations. It is really more cost effective and best for our long term strategic security to find a country sitting on an existing large oil reserve that we can find a reason to justify taking over and re-making into a nice, freiendly, pro-american oil producing client state. Oh wait, that's the iraq plan...lives are after all always cheaper to spend than corporate profits.

Re:Research (5, Insightful)

iocat (572367) | more than 11 years ago | (#5043125)

The problem is that *no* alternative to oil will enable people to live with the same wasteful energy useage that oil does. The EROI (energy return on investment) for oil is just way, way higher than for geo, wind, solar, etc.

So even a "Manhattan Project" style affair will be worthless unless we also make a concerted effort to dramatically improve the energy efficiency of our society -- our cars, our appliances, our homes, etc.

With not much effort, by not a huge percent of the population, California was able to fairly significantly reduce its energy needs during the whole Enron-initiated "power crisis." Not to sound polyannaish, but just imagine what would happen if we all actually did some simple, painless, things that saved energy.

The problem is that most people need a real incentive -- dramatically higher costs -- before they will conserve.

Re:Research (0)

Anonymous Coward | more than 11 years ago | (#5043182)

The problem is that *no* alternative to oil will enable people to live with the same wasteful energy useage that oil does. The EROI (energy return on investment) for oil is just way, way higher than for geo, wind, solar, etc.

Nuclear is quite competitive, and it's here today. It powers most of France right now.

Re:Research (2)

timeOday (582209) | more than 11 years ago | (#5043128)

That's highly ironic, since the Manhattan Project already resulted in an alternative energy source with practically unlimited potential and minimal environmental impact.

As for GWB, he isn't the first president to not solve this problem. Jimmy Carter probably took the best swipe at it (creating the Dept. of Energy and all) and look what happened to him.

Re:Research (0)

Anonymous Coward | more than 11 years ago | (#5043155)

"the Manhattan Project already resulted in an alternative energy source with practically unlimited potential and minimal environmental impact"

Are you out of your mind? Chernoby ring a bell? www.chernobyl.com Not to mention that used nuclear waste is radioacive for thousands and thousands of years. Ask the folks in Nedeva how they are going to like having the nations nuclear waste in their backyard. Nuclear power is not the solution. Germany is phasing out it's nuclear power plants....the time is over for nukes.

Re:Research (2)

theLOUDroom (556455) | more than 11 years ago | (#5043141)

What the US needs is a Manhattan Project for alternative energy to oil.

I completely agree. All we need to do is throw enough time and effort (and money) at researching alternative energy and something good is bound to happen.
They've already hit the break even point for fusion reactors (getting as much power back as they put in). It seems to me that if we cared enought to fast-track it or some other alternative energy source's development, we could have something fairly soon.

Who elected George Bush anyway?
Not me.

Re:Research (0)

Anonymous Coward | more than 11 years ago | (#5043190)

More like a 'Rio Linda' project based on the simpleton lame-brained eco-wannabe comments made on /.

silicon chip micro rectennas? (3, Funny)

JeanBaptiste (537955) | more than 11 years ago | (#5042967)

I dont want to 'explore' any such technology if a rectennas are what I think they are

Re:silicon chip micro rectennas? (0, Offtopic)

iggymanz (596061) | more than 11 years ago | (#5043186)

And we ALL know what rectennas explore in Soviet Russia!! And with no vaseline, either!

Nyeeeeeeeeet !!!!!!!

Cost issues (1)

lurgyman (587233) | more than 11 years ago | (#5042972)

Too much money for R&D for too little return.

Cost issues (2)

simpl3x (238301) | more than 11 years ago | (#5043108)

while there most certainly are cost issues, people feel the need to wait until the efficiency is at 70%!

i refuse to buy a computer until i can buy a 1000gflop machine for a hundred bucks!

perhaps too much thinking, and not enough doing. there is a point at which the market can take over, but the market has to be facilitated

Where are they? (5, Interesting)

nuggz (69912) | more than 11 years ago | (#5042978)

I would guess the inventor couldn't get it to work, which is why they never took advantage of it.
The patent just expired. It takes a while to develop and prove out a new technology.

I see lots more work on windmills for alternative power. Many have shelved solar panels because the current ones have poor performance.

Re:Where are they? (5, Interesting)

rodgerd (402) | more than 11 years ago | (#5043013)

Living in a rainy country, something which has caught my attention are small hydroelectric units that can be dropped into streams and rivers crossing one's land (for that matter, any fall of water will get you power, so water collected from the roof of a tall building during monsoon season in the tropics may be viable).

cost? (5, Insightful)

Ashish Kulkarni (454988) | more than 11 years ago | (#5042980)

Even if someone does find a way to implement such high-efficiency converters, the cost has to be low for wide-scale use...otherwise it'll just be something used in specialized applications (eg. space)

Re:cost? (3, Insightful)

Drakula (222725) | more than 11 years ago | (#5043137)

Cost is always an issue for optoelectronic based technology. The overheard for production of the devices is large, from the the equipment required for processing right down to the materials themselves. However, the cost comes down when and if a large number of consumers by them. Look at CD/DVD players. Their high cost was due to the lasers involved, not the rest of the component. Once everyone and their uncle started buying them the cost came down, way down. These components are dirt cheap now.

Now these converters are a different story. Even if they were that efficient, they cost would be so large, like you pointed out, it would be prohibitive for the average consumer. However, with efficiencies that high, eventually lots of people would want one and probably bring the cost down.

Re:cost? (2)

hackstraw (262471) | more than 11 years ago | (#5043143)

I agree this link [doe.gov] says that a current system which is connected to the main power grid and sells excess electricity back to the power company will not pay for itself in 30 years.

Check your math. (3, Insightful)

gurps_npc (621217) | more than 11 years ago | (#5042981)

The Patent said it could reach 70% (Theoretical, as they did not build) It also said that current state of the art (in 1970) was 20% Theoretical, 10% practical. (1/2) using that same ratio, the 70% Theoretical technology should be producing 35% pracitcal. We currently have 17% practical, about 1/2 of what their technology could do. Frankly, the 7% increase is reasonable for most technologies, excluding the computer chip (which contrary to Moores law has been doubling every 3 years or so)

It would certainly be nice. (0, Troll)

AmiNTT (539586) | more than 11 years ago | (#5042993)

If 70% is actually possible, then it would certainly make solar power more attractive to power generation companies.

It would be even better for those who live in the boonies - places where power is generated by diesel generators etc..

I suggest that rather than spending money on the TIA initiative, that the money be spent bringing me the 70% efficient solar cells and flying cars! I was promised flying cars! ;-)

Re:It would certainly be nice. (1)

Grenade of Antioch (635095) | more than 11 years ago | (#5043036)

Yes but people would just complain that the flying cars were interfering with the spotted owls, that the large SUV flying cars blotted out a disproportionate share of the sun, etc. I think we'd all be better off living the natural way- in caves...

Re:It would certainly be nice. (1)

LaissezFaire (582924) | more than 11 years ago | (#5043091)

While solar power is nice, even at 100% you need some good-old-fashioned nuclear, hydro, or fossil fuel power. The limit on how much energy you get (based on the light that falls on the earth), not to mention the cloud cover and hours of darkness stuff, is just too great.

What I want is power like the E. E. "Doc" Smith space opera books. Now that's power.

Re:It would certainly be nice. (2)

david duncan scott (206421) | more than 11 years ago | (#5043252)

You mean like the space ships powered by Diesel engines? I sometimes wonder if Smith ever read the stuff that poured from his typewriter.

Flying Cars (1, Redundant)

Lxy (80823) | more than 11 years ago | (#5043005)

I was promised flying cars too. Where are the flying cars?

Re:Flying Cars (0)

Anonymous Coward | more than 11 years ago | (#5043188)

Here's one: http://www.moller.com/news/

Reserve yours now while you still can!

It's the effeciency of $ to power conversion (1)

jj_johny (626460) | more than 11 years ago | (#5043009)

Hey, the problem is that the cost per Kwh produced is just too high regardless of effeciency. Granted that the effeciency means that you could use it in more places where there is less sun or less space.

lying hippy bs - solar power sucks (-1)

neal n bob (531011) | more than 11 years ago | (#5043015)

We need more nuclear plants. Concentrated mainly in Massachusetts and California.

Re:lying hippy bs - solar power sucks (0)

Anonymous Coward | more than 11 years ago | (#5043071)

But only if they use the Chernobyl design.

Much to blame in Oil and Gas Companies (1)

Yiliar (603536) | more than 11 years ago | (#5043019)

It is unfortunate that the rise in interest in alternate fuels coincided with the oil and gas boom.

It was interesting to me to acutally witness several oild and gas company's R&D groups drop all of their alternative energy programs during the early nineties.

It is now impossible for the oil and gas companies to do the major R&D in these areas.

It is a true shame that they did not do it when they could.

Ask yourself... (3, Insightful)

anthony_dipierro (543308) | more than 11 years ago | (#5043022)

Why haven't you built one of these things? Chances are that's the same reason that they haven't yet been built.

Re:Ask yourself... (5, Funny)

deft (253558) | more than 11 years ago | (#5043085)

"Why haven't you built one of these things? Chances are that's the same reason that they haven't yet been built."

90% of slashdot just simultaneously realized that these solar panels havent been developed because they are too busy looking at porn and playing warcraft.

Re:Ask yourself... (1)

Bob McCown (8411) | more than 11 years ago | (#5043178)

Why haven't you built one of these things? Chances are that's the same reason that they haven't yet been built.

Er, cause I left my fabrication factory in my other pants?

GE.. (1, Insightful)

grub (11606) | more than 11 years ago | (#5043027)


The world power conglomerates keep these inventions from becoming reality. They have too much to lose by people not using nuclear|hydroelectric electricity or burning dead dinosaurs.

Possibly overlapping Patents? (4, Interesting)

SpeedBump0619 (324581) | more than 11 years ago | (#5043031)

Could it be that the effect in question has been patented for some other use [foveon.com]? I'm not familiar with the patent quagmire, but multiple similar uses for the same physical phenomenon (light absorbtion into silicon) might be the issue...

Perhaps impractical to actually build? (4, Informative)

ivan256 (17499) | more than 11 years ago | (#5043060)

This device may be fabricated upon a transparent slab by the deposition of one or more metal coatings in a known manner. The various rectifier elements are first prepared by opening appropriate windows in the metal coating utilizing an electron beam and suitably coating and doping the rectifying areas. An electron or ion beam cuts the shape and connections shown. The connections are completed after deposition of the insulating coating 9. The circuit is then the same as that shown in FIG. 1.

Assuming the applicant built a prototype and proved this device works, creating metal coatings in the exact thicknesses he mentions with the detail he describes is still something that would be very expensive to do now. That technology hasn't improved very drastically in the last decade or so.

I would love.. (1)

Gortbusters.org (637314) | more than 11 years ago | (#5043069)

to have any solar energy powering my home. If it ever became popular, do you think there would be solar tax? ah-haha!

I built a Rectenna (-1, Troll)

Anonymous Coward | more than 11 years ago | (#5043083)

It can detect linux zealots from 2 miles away, with 70% efficiency.

Now we can get back to work (0)

Anonymous Coward | more than 11 years ago | (#5043089)

Now that the patent has expired, there is once again an incentive for people to work on them. The 17-to-20 year runaway-inventions dampening effect has performed as designed.

Where are the 70% Efficient Solar Cells? ask GWB (1, Interesting)

t0qer (230538) | more than 11 years ago | (#5043098)

GWB is a texan. Texas oil is a huge part of their economy. Texas oil makes cars go vroom, keeps power plants running, and heats people's houses on the east coast.

What would happen if all the major automakers decided tomorrow to start building electrics? GWB's texan constituants would have a cow. They would be trying to pass laws to outlaw them.

When it was clinton/gore presidency, everything was dumped into technology, the GM EV1 is a classic example of the innovations that occured under a goverment that supported research that would cut out our dependance on foriegn (read Iraq) oil. IIRC Clinton even made it a law that all US automakers would have to have an electric vehicle on the market by 2008, and that these cars would have to be built along strict goverment guidelines.

When Bush became president, he wasted no time in modifying the law. Current guidlines are on par with a golf cart with turn signals and mirrors. Fords paltry offering into this market is just that, a golf cart with mirrors and turn signals.

Sorry I turned this comment into a political rant, conspiracy theories aside, the fact that GWB would kill the alternative fueled car laws and go after Iraq oil is all the proof I need.

Re:Where are the 70% Efficient Solar Cells? ask GW (4, Insightful)

Mantrid (250133) | more than 11 years ago | (#5043144)

Okay here's my problem with your argument:

If GWB is so concerned about keeping the Texas oil economy going and appeasing the Texas oil companies, wouldn't he want to avoid increasing the supplies of oil, especially foreign oil? If GWB annexed Iraq and started sucking out all the oil for US use, that would just tank the prices of oil and lower the demand for Texas oil.

Plus he's POTUS now, not Governer of Texas, he has more people to appease then just the Texans. (And if it was so easy to invent alternative energy he'd score far more points across the board then he would lose in Texas)

Bush & Cheney both sold off their stocks (at a loss at the time), to limit their conflict of interest with the oil companies.

It isn't GWB holding up electric cars in some oil conspiracy, it's the population as a whole - who collectively don't seem all that interested in alternative fuel vehicles or higher fuel usage vehicles. Then there's the money for whatever new infrastructure is required by alternative energy...

Re:Where are the 70% Efficient Solar Cells? ask GW (5, Interesting)

Photon Ghoul (14932) | more than 11 years ago | (#5043177)

For a time, I lived in a so-called Texas oil town during the late 80's and early 90's. A family member worked on oil rigs there. The town itself was a ghost-town (and is much worse within the last few years) because the government paid the oil producers to shut down the wells. Texas oil is more expensive to drill, retrieve and refine than just buying tanker-full shipments of imported oil. If anything, the "Texas oil economy" probably revolves more around importing and off-shore drilling. Just a detail there for ya, "partner".

Do you have a URL for Bush's guidelines on electric vehicles?

What, or rather Who keeps this off the market? (5, Funny)

mcmonkey (96054) | more than 11 years ago | (#5043101)

Who controls the British Crown?
Who keeps the metric system down?
We do, we do.
Who keeps Atlantis off the maps?
Who keeps the Martians under wraps?
We do, we do.
Who holds back the electric car?
Who makes Steve Guttenberg a star?
We do, we do.
Who robs cave fish of their sight?
Who rigs every Oscar night?
We do, we do!

Not with semis (5, Informative)

sirsex (550329) | more than 11 years ago | (#5043104)

Semiconductor photocells can easily be >90% effecient, but over a rather small range of wavelengths. This is due to the bandgap. An electron is freed if the electron gains enough energy from the photon(s) to overcome the bandgap. the energy of several photons can be combined to free and electron, but is lossy. If the photon has more energy than is required to free the electron, the extra will mostly be dumped as heat. The equation governing wavelength, energy, and Boltzmann's constant is

E=hw

Silicon is actually a rather poor photomaterial, being an indirect material, it's limited to about 60% effeciency at any wavelength. The electron must not only gain energy, but also move a slight bit within the crystal in order to reach the conduction band. Direct materials, such GaAs, being direct, can be > 95%

Perhaps the are other techniques??

Anyone know the energy in sunlight? (3, Insightful)

cornice (9801) | more than 11 years ago | (#5043142)

I know this is a dumb question. I remember hearing the answer back in high school but I have since forgotten it. I want to know the total energy in sunlight. I know it varies widely depending on location and weather but an average or a range per square foot, square yard, acre or whatever would be interesting. I ask because I think some people overestimate the value. If you can produce a 1 inch square solar cell that's 100% effecient but it costs $1000, then it's never going to pay for itself except in space applications. The big payoff for solar cells will come when you can produce them for almost nothing and plaster them over everything. When that cool, one way billboard plastic wrap stuff that covers busses also acts as an 80% effecient solar cell, then we'll see more of this stuff.

Re:Anyone know the energy in sunlight? (1)

Molander (97095) | more than 11 years ago | (#5043196)

On a good summer day in Stockholm Sweden we get
700 - 900 Watts per square meter.


I don't remember the value for a rainy day but
it is much lower, say 10 - 50 W/m2.

/Thomas

Re:Anyone know the energy in sunlight? (0)

Anonymous Coward | more than 11 years ago | (#5043202)

It can vary widely with season, weather, etc., but a rough and easy-to-remember rule of thumb for a clear day, facing the sun directly is 1kW per square meter. In orbit it's about 50% higher, perhaps more if you can convert the really high-energy UV and other more esoteric radiation.

Re:Anyone know the energy in sunlight? (1, Informative)

Anonymous Coward | more than 11 years ago | (#5043225)

On average, 1.6 kilowatts of light per square meter hit the Earth. Because of cloud cover and other variables, it is often rounded to one kilowatt per square meter for solar energy calculations.

This is a hell of a lot of energy, and it's damn shameful that we are still burning dinosaur juice just to make some wealthy bastards richer.

Oh yeah, fuck you Bush.

Spectrolab Holds Title for Most Efficient (1, Informative)

Anonymous Coward | more than 11 years ago | (#5043148)

All comes down to physics...most patents are not filed by technical people, but by money grubbing swine *cough* lawyers *cough*.

ANYway...

The current record for a terrestrial cell is from Spectrolabs @ 34%. For spacebased cells it is around 32%.

The company is located here:
http://www.spectrolab.com

and products located here:
http://www.spectrolab.com/prd/prd.asp

Here it is. The inventor calls it lepcon. (5, Informative)

RealAlaskan (576404) | more than 11 years ago | (#5043153)

Right here [sintef.no]. Scroll right down to the bottom of the page. The patent holder, Alvin Marks, calls this approach lepcon. He's more excited about another approach, called lumeloid. Someone else has already linked to the site [luminet.net] he has for that.

It looks as if this is all still very blue-sky, and there is no reason to think that these nifty ideas will work in practice. The first page I linked to tells us: ``Dr. Marks is in negotiation with U S. government to fund Lepcon research and development.'' Probable translation: ``He's applying for grants, because he can't sell it to the venture capitalists.''

"visible" light rectennas do not exist (0)

Anonymous Coward | more than 11 years ago | (#5043167)


Fundamental problem is while materials science has known how to make electrons "flow" (and thereby make current) in certain materials due to being exposed to microwaves, no such material exists for visible light. PV solar cells use the concept of band jumping (very inefficient).
Sound like the patent says let's mimic nature's way to converting visible light into electron flow. I do not know much about biology, but I thought nature wasn't very efficient at doing this either.

Easy (2)

Euphonious Coward (189818) | more than 11 years ago | (#5043214)

Making these things is really, really easy. All you need is an array of 100 teraHertz diodes, see...

Oh, you haven't figured out yet how to make diodes that can switch at 100 THz? Never mind.

PVs can exceed 35% efficiency (4, Interesting)

leftism11 (177941) | more than 11 years ago | (#5043223)

http://www.spacedaily.com/news/solarcell-01h.html

This article mentions Tecstar--apparently the leading supplier of high-output PV cells for space missions. They made the cells for the Mars lunar rover, among other projects.

The difficulty is that manufacturing the cells is very difficult and expensive, requiring multi-million dollar Metal Oxide Chemical Vapor Deposition (MOCVD) machines. Due to variations in the rather elaborate manufacturing process, the yields vary greatly, and also produce cells that have widely varying efficiencies. Some cells fall below a given spec, while others exceed the spec.

In order to achieve a given power output for a space system, they are able to mix the under and overperforming cells into an array that provides the necessary power.

So, although some cells may only provide 30% output, a few will exceed specs, and thus provide > 35% efficiency. The challenge is delevoping manufacturing processes that improve yield and thus reduce costs.

Why aren't we ever going to see these type of cells on earth? Cuz they cost millions of dollars to produce, and there is a multi-year order backlog for them for planned space missions. Unless hundreds of millions of $ gets directed towards making them a commodity, well, you know the story...

The folks at NREL are fixing photovoltaics... (3, Informative)

mengel (13619) | more than 11 years ago | (#5043235)

The folks over at NREL [nrel.gov] are working on [nrel.gov] multijunction photovoltaics. They've gotten 25% efficiency with 2 junction-layers instead of 1, and are going for 33% with a 3 junction-layer cell. I saw a talk by one of the folks doing that work a few months ago. Basically at the moment they're targeting the space program as customers, because the cost of launching solar panels is major.

But as to making micro-antennas that work in a broad enough bandwidth to beat solar cells, no I don't think they're playing with that. But you're talking something painfully small, even at current technologies, I would think. Those 17% efficient solar cells work up at the blue/ultraviolet range. If you look at the spectrum [electric-words.com] that tells you the wavelength of UV is 10**-8 meters, or 10nm. Now a current transistor on a chip is about 180nm; so to get that bandwidth with an antenna you need a component about 1/10th the size of current chip components, and if you want to do one of those fractal, broad-spectrum antennas, you need sections of antenna at least 1/8 that size... So given Moore's law, you're still 10 years off.

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