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New Solar Cell Sets World Efficiency Record
Posted by
ScuttleMonkey
on Mon Sep 29, 2008 01:33 PM
from the hot-tech dept.
from the hot-tech dept.
asoduk writes to tell us that a new world record has been set for the most efficient photovoltaic device. Topping the scale at 40.8% efficiency, the new solar cell differs significantly from the previous record holder. "Instead of using a germanium wafer as the bottom junction of the device, the new design uses compositions of gallium indium phosphide and gallium indium arsenide to split the solar spectrum into three equal parts that are absorbed by each of the cell's three junctions for higher potential efficiencies. This is accomplished by growing the solar cell on a gallium arsenide wafer, flipping it over, then removing the wafer. The resulting device is extremely thin and light and represents a new class of solar cells with advantages in performance, design, operation and cost."
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very cool, but... (Score:3, Insightful)
Call me in 20 years when they're in production. Seems it always takes that long for these innovations to get to market nowadays.
Re:very cool, but... (Score:4, Funny)
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Re:very cool, but... (Score:4, Informative)
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Re:very cool, but... (Score:5, Insightful)
Fission very well could be, but half-vast fission we've been saddled with as a result of the Carter administration's (the one president who should've known better, btw, what with his degree in nuclear engineering) machinations.
Things tend to cost a lot more when you throw away (and have to devise elaborate means to protect yourself from) 98% of your fuel as "waste" because you don't want terrorists to be able to make nuclear bombs.
Parent
Re:very cool, but... (Score:4, Interesting)
hey... Thats my argument!
If we built 10 thousand square miles of solar thermal power plants in the US southwest and a few hundred feeder-breeder reactors elsewhere, we could completely replace the low efficiency and high pollution electrical production of the US while expanding our capacity to be 2 or more times its current amount.
This would allow us to also switch over to grid powered electric rail lines and widespread use of economical electric cars. Even without dramatically improved battery technology, long distance private vehicles could become viable if a charging rail system was installed along interstates and major highways to allow short range EV to charge on the move.
The cost of the initial investment would be high (a few trillion) but over the course of a few decades it would easily pay for itself (assuming electrical rates similar to today).
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Re:very cool, but... (Score:4, Insightful)
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Re: (Score:3, Insightful)
Nowadays, most music is too cheap to meter (or matter.)
Re:very cool, but... (Score:5, Funny)
Parent
yaaawwwwnnn.... (Score:5, Insightful)
Re:yaaawwwwnnn.... (Score:5, Informative)
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Re:yaaawwwwnnn.... (Score:4, Informative)
actually, the dark side of the moon is more dark.
In the moons night sky, the earth is more than 4 times larger than the moon is in our sky. The earths albedo is also about 3 times higher than the moon. So "Earthshine" on the moon is about 12 times brighter than moonshine is on earth.
Effectively, the night time on the far side of the moon is about 12 moonshines darker than the near side.
Parent
Re:yaaawwwwnnn.... (Score:5, Interesting)
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What's your market? (Score:5, Insightful)
I'm just curious-- not implying that your calculations are wrong. I'm at the extreme other end in Arizona, and payback appears to be in the 10-15 year range for us, not counting resale and using a constant price for power for the next 15 years. That's well within the system warranty time, but may still be a bit too much for people to pay for up front.
Payback speed depends heavily on your local utility, their rates, their incentives, and whether they allow net-metering over the entire year, or just monthly. It also depends on whether or not you are willing to consider resale value as part of your payback time.
I suspect Hawaii is even better than Arizona despite having more cloudy days, just because power is so freaking expensive there.
In the long run, I think leases will win out. A couple of companies are offering deals where you lease the system and panels, and they promise your new smaller electric bill plus the lease cost will be lower than your current electric bill. A deal like this makes things suddenly interesting to people who don't have $20k to drop up front.
Parent
Re:yaaawwwwnnn.... (Score:5, Informative)
"Complete" solar's ROI is 20 years, but solar hot water heaters here in Hawaii - where we get a lot of sun - with the federal solar tax credit - I'll make my money back in O N E year!
Parent
Re: (Score:3, Informative)
I'm not so sure. I use gas for hot water only right now; my gas bills are $15-20 a month. A fair chunk of that is the line fee, so if I install a gas stovetop, as my wife insists we will, I'll be paying that anyway. Even if I could disconnect it entirely, it's barely feasible to put in solar hot water & have it pay for itself in 20 years. I was all fired up to do it last year, but when I ran the numbers it just wasn't worth it.
Re: (Score:3, Insightful)
40% starts to get interesting. (Score:5, Informative)
none of this matters unless ..... (Score:4, Insightful)
I no longer get excited about stories like this, as it doesn't matter unless someone figures out how to mass produce this stuff and make it available for the market. If I'm not mistaken photovoltaic production hasn't changed in years despite all this new technology. Why not run a story on why mfgs are taking so long to adopt this.
Parent
Re: (Score:3, Insightful)
Re: (Score:3, Insightful)
IMHO, it's energy *storage* that matters more than generation. It seems like over time, even "normal" solar cells or wind power could build up an excess of energy that would cover night time, air conditioning, clouds, etc, but there's no practical way of storing the generated energy to use later.
Re:no need to 'store' electricity. (Score:4, Insightful)
I actually think there is a simple source to this. It's not so much to store energy but to re-direct it. If home owners with solar arrays are hooked up to the electrical grid they can sell power to the grid during the day to supply business and manufacturing. Then at night the grid will forward excess power not used by business back to the homeowners. There is no need to 'store' energy in the traditional sense.
Parent
Important information missing? (Score:3, Insightful)
Even TFA doesn't say what the previous record was or provide any quantitative comparison.
Re:Important information missing? (Score:5, Funny)
The new cell produces enough electricity that if you covered a football field with them, it would be enough power to run an Olympic swimming pool full of hard drives. The additional electricity these cell provide compared to the previous record holder would allow you to copy several libraries-of-congress per second faster to your pool full of drives.
Hope this helps.
Parent
Re:Important information missing? (Score:4, Funny)
Can I have a car analogy instead?
Parent
Re:Important information missing? (Score:5, Funny)
they get roughly 32 rods per hogshead. divide that by the current vegas odds of the LHC finding the higgs boson vs sucking the world into a micro black hole, and you'll realize that is one hell of a burrito for only $700b.
Wait a minute. What was this thread about again?
Parent
Re:Important information missing? (Score:5, Informative)
The previous record holder was 40.7% [engadget.com]
I'm not sure why this is here, this was a press release in Mid august.
Parent
TFA (Score:5, Informative)
Was taking forever to load, so here's the article:
Scientists at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have set a world record in solar cell efficiency with a photovoltaic device that converts 40.8 percent of the light that hits it into electricity. This is the highest confirmed efficiency of any photovoltaic device to date.
The inverted metamorphic triple-junction solar cell was designed, fabricated and independently measured at NREL. The 40.8 percent efficiency was measured under concentrated light of 326 suns. One sun is about the amount of light that typically hits Earth on a sunny day. The new cell is a natural candidate for the space satellite market and for terrestrial concentrated photovoltaic arrays, which use lenses or mirrors to focus sunlight onto the solar cells.
The new solar cell differs significantly from the previous record holder - also based on a NREL design. Instead of using a germanium wafer as the bottom junction of the device, the new design uses compositions of gallium indium phosphide and gallium indium arsenide to split the solar spectrum into three equal parts that are absorbed by each of the cell's three junctions for higher potential efficiencies. This is accomplished by growing the solar cell on a gallium arsenide wafer, flipping it over, then removing the wafer. The resulting device is extremely thin and light and represents a new class of solar cells with advantages in performance, design, operation and cost.
NREL's Mark Wanlass invented the original inverted cell, which recently won a R&D 100 award. His design was modified by a team led by John Geisz that further optimized the junction energies by making the middle junction metamorphic as well as the bottom junction. Metamorphic junctions are lattice mismatched - their atoms don't line up. The material properties of the mismatched semiconductors allows for greater potential conversion of sunlight.
NREL is the U.S. Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by Midwest Research Institute and Battelle.
Old? (Score:5, Informative)
http://www.treehugger.com/files/2006/12/new_world_recor.php [treehugger.com]
TFA is slashdotted, but a little googling shows this happened two years ago.
Re:Old? (Score:5, Funny)
No, that was 40.7%. Old and busted.
This is 40.8%. :p
Parent
When we'll have solar (Score:5, Funny)
Re:When we'll have solar (Score:5, Interesting)
Parent
Cool and not cool (Score:4, Interesting)
Indium is a very rare material, one which we're slated to deplete in less than 10 years or so at current rates of consumption, due in part to its use in display screens.
I highly doubt that widespread use in solar cells would be feasible.
Nice efficiency, though.
You all got your ratios wrong (Score:4, Interesting)
Why does everyone think these would be used to produce electric power for domestic use? Something like this is much better suited for use on spacecraft.
When you are covering your roof you care about the power/cost ratio. On spacecraft you care a lot about power/weight ratio. This new type of cell address power/area which translates directly to power/weight
*sigh* Wrong research focus (Score:4, Insightful)
Does this need to be said again? There's no shortage of roof space and other places to locate solar cells, so the efficiency of the cells is only a marginal issue; the bigger issue is COST. Instead of focusing all the research on this penile my-cell-is-more-efficient-than-YOURS pissing contest, it ought to be focused on finding least toxic and least expensive means of production. Certainly large scale mass production will eventually reduce costs, but large scale adoption won't occur until they can be produced inexpensively enough in the first place to motivate widespread use. Efforts should be focused on finding the least expensive and least toxic method of production for now, and worry about improving efficiency once their use has become commonplace.
Re:So... (Score:4, Funny)
Just guessing here... 3-5 years.
Parent
Re:So... (Score:5, Interesting)
How much do they cost and when can I get some?
If the goal here is to move away fom the consumption of materials in short supply, solar cells based on gallium and indium aren't going to help. We had a world-wide gallium shortage at the turn of the millenium, and that only receeded because demand slacked off some. There is currently a shortage of indium that started in 2007.
Both of these elements are hard to come by because they are not just rare, but sparsely distributed. Indium is produced from lead, zinc, and tin production waste, and I think gallium mostly from aluminum production waste. I'm sure supply will increase over time, but we can't quickly ramp up production of either element by "mining more".
Niether of these elements would remain economical if there were a sharp spike in demand.
Parent
Re:So... (Score:5, Funny)
I don't see the problem. All we need to do is develop a cheap, efficient form of fusion to create the exotic elements we need so that we can produce these solar cells to provide a new source of cheap, efficient energy.
Parent
Why waste time when you can make gold (Score:4, Funny)
Why mess around with solar cells when you can use that technology to turn lead into gold. We'll have so much gold that everyone on this planet will be so rich that they won't have a need for cheap solar power.
Parent
Re:So... (Score:4, Insightful)
Parent
Re:sounds toxic (Score:5, Funny)
Unless you grind them up and snort them you're probably safe.
Parent
Re: (Score:3, Funny)
Unless you grind them up and snort them you're probably safe.
Oh crap... You mean you're not supposed to do that!?!?
I better call my doctor.
Re:sounds toxic (Score:4, Interesting)
Please choose a doctor:
A. Doctor McCoy, who's going to make you take some magical pills and ask you to get a good night sleep.
B. Doctor Crusher, who'll treat you and then send you to counselor Troy to deal with any emotional damage.
C. Doctor Bashir, who'll invent a whole new treatment because he can't be bothered by "ancient techniques" created by normal humans.
D. The Doctor, who'll simply laugh at you while mentioning something along the lines of "hologram can't be harmed by such trivial things".
E. Doctor Phlox, who probably has some kind of alien leeches he can put on you to drain out the toxins.
F. The Doctor. He's not a real doctor, but I guess he could send you back in time to warn yourself not to do that in the first place.
Parent
Re:sounds toxic (Score:4, Funny)
I will personally guarantee to you that they are not cancergnous.
Parent
Re:Cost per Watt more important (Score:5, Interesting)
There is more than one company who claims to be on the way to $1/Watt.
But right now, subsidies in Germany are so high that PV vendors can sell for more than $1/Watt, and find customers. So you will get $1/Watt on the end user market when the German market is saturated, which will probably take a few more years.
On the upside, we Germans essentially pay for the development of all those nice improved PV cells, because our subsidies guarantee a market ;-)
Parent
Re:please mirror (Score:5, Funny)
Alternatively, you can use a Fresnel lens instead of a mirror.
Parent
Re:I would love to see, for once (Score:4, Insightful)
So you want an advertisment?
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Expensive! (Score:5, Insightful)
These things will be *very* expensive, I'll guess that the main application will be in spacecraft solar panels.
First, they use gallium, which is an expensive material. Second, from the description in the summary (TFA is slashdotted), they do one side, then flip it over and etch the backside to get at the junction from the back. Seems like a costly manufacturing process.
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Re:Expensive, poisonous... (Score:4, Insightful)
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Supply hiccup due to storm.. (Score:5, Insightful)
Price gouging: Not enough of it.
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Re:Terducken power wafers (Score:5, Funny)
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