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New Solar Cell Sets Record For Energy Efficiency

samzenpus posted 1 year,27 days | from the getting-closer dept.

Power 165

Lucas123 writes "After three years of work, German and French researchers have achieved a new world record on converting sunlight to energy through a photovoltaic cell, achieving a 44.7% rate of efficiency, which was measured at a concentration of 297 suns. The efficiency rating means the solar cell collects 44.7% of the sun's spectrum's energy, from ultraviolet to the infrared spectrum, which is converted into electrical energy. The team of researchers said the technology places them on the path to achieving their roadmap of 50% efficiency in solar energy conversion."

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boring (0)

geekoid (135745) | 1 year,27 days | (#44965697)

eet me know when they got to 120%.

heh.

This is good news.

The 44.7% efficiency requires 297 suns (1)

Taco Cowboy (5327) | 1 year,27 days | (#44966429)

I was excited when reading the "Set Record" claim in the title. However, upon reading the following:

"...a photovoltaic cell, achieving a 44.7% rate of efficiency, which was measured at a concentration of 297 suns"

my excitement was very much doused.
 
I will be waiting for the day when someone come up with a solar cell that can achieve 50%+ conversion rate with the 1 sun that we have.

Re:The 44.7% efficiency requires 297 suns (5, Informative)

ShanghaiBill (739463) | 1 year,27 days | (#44966475)

"...a photovoltaic cell, achieving a 44.7% rate of efficiency, which was measured at a concentration of 297 suns"

This means that they use mirrors to focus the light onto the panel. Since high-efficiency panels tend to be expensive, the more light you can concentrate on it, the better. The fact that it can handle a near 300 fold increase in throughput is a good thing. These are not going to be used on a residential roof flat panel anytime soon.

Re:The 44.7% efficiency requires 297 suns (4, Insightful)

rahvin112 (446269) | 1 year,27 days | (#44966683)

It will take a while for the technology to hit the manufacturers but it will hit panels for satellites first. When you are paying $20k per pound (0.5kg) to put something in space if you can get a higher efficiency with less weight you can pay a LOT more for the panels and still come out ahead.

Re:The 44.7% efficiency requires 297 suns (1)

ChrisMaple (607946) | 1 year,27 days | (#44966953)

Reflectors aren't weightless, and neither are the extensive heat removal systems that will be required to cool a concentrated solar cell in space. I've never seen a representation of a satellite with anything but unconcentrated cells.

Re:The 44.7% efficiency requires 297 suns (1)

pla (258480) | 1 year,27 days | (#44967433)

Reflectors aren't weightless, and neither are the extensive heat removal systems that will be required to cool a concentrated solar cell in space. I've never seen a representation of a satellite with anything but unconcentrated cells.

Pssst - Although not guaranteed, if they get 44.7% efficiency at 300x normal sunlight... They probably do similarly under 1x sunlight. Claims like the one made don't describe a requirement for that efficiency, they describe an extreme under which the cells can still perform. As in "oooh, we only need one $1000 panel and 297 $10 mirrors, rather than 297 $150 panels"

Re:The 44.7% efficiency requires 297 suns (1)

gadget junkie (618542) | 1 year,27 days | (#44968323)

Reflectors aren't weightless, and neither are the extensive heat removal systems that will be required to cool a concentrated solar cell in space. I've never seen a representation of a satellite with anything but unconcentrated cells. Pssst - Although not guaranteed, if they get 44.7% efficiency at 300x normal sunlight... They probably do similarly under 1x sunlight. Claims like the one made don't describe a requirement for that efficiency, they describe an extreme under which the cells can still perform. As in "oooh, we only need one $1000 panel and 297 $10 mirrors, rather than 297 $150 panels"

......And, 297 times the surface, plus the added wiring etc. Only way to measure in a meaningful way is fixed cell, no concentrators, 10+ days during the equinox. Ah, do not forget diesel generators or batteries to guarantee continuous output, will ya?

Re:The 44.7% efficiency requires 297 suns (0)

Anonymous Coward | 1 year,27 days | (#44968541)

Fine, you might not find them useful.

I'm pretty sure that there are others who do, smarter people with more money.

Re:The 44.7% efficiency requires 297 suns (1)

K. S. Kyosuke (729550) | 1 year,27 days | (#44968979)

Ah, do not forget diesel generators or batteries to guarantee continuous output, will ya?

Isn't it better to stop looking for excuses why not to upgrade the energy (re)distribution infrastructure? Over a large area, there's sun or wind somewhere most of the time, definitely more often than over a small area. Perhaps it's time to stop thinking locally.

Re:The 44.7% efficiency requires 297 suns (2)

K. S. Kyosuke (729550) | 1 year,27 days | (#44968969)

I've never seen a representation of a satellite with anything but unconcentrated cells.

What about Deep Space 1 [nasa.gov] ?

Re:The 44.7% efficiency requires 297 suns (3, Interesting)

icebike (68054) | 1 year,27 days | (#44966611)

Yawn...
Another day another solar cell breakthrough that wont see the light of day (see what I did there) for 10 years if ever.

Why is it none of these ever make it to manufacture. Typical solar panels have an average efficiency of 15%, with the best commercially available panels at 21%.
Yet we get a new announcement weekly.

Re:The 44.7% efficiency requires 297 suns (3, Insightful)

notanalien_justgreen (2596219) | 1 year,27 days | (#44967161)

It's not really efficiency that determines the profitability of solar cells. It's the ratio of Efficiency / $. These might be the most efficient ever produced, but they're likely substantially more expensive than the 15% variety (i.e. 3x more efficiency at 10x the cost).

Re:The 44.7% efficiency requires 297 suns (2)

DrXym (126579) | 1 year,27 days | (#44968753)

Sometimes cost isn't the only determining factor. Space and weight could be equally important considerations. e.g. maybe the difference in efficiency between two devices means one is compact enough to stick into a backpack and charge a phone/laptop in a reasonable amount of time and the other one isn't. Even if it costs more money, it may be the only viable option.

Re:The 44.7% efficiency requires 297 suns (1)

K. S. Kyosuke (729550) | 1 year,27 days | (#44968963)

It's not really efficiency that determines the profitability of solar cells. It's the ratio of Efficiency / $. These might be the most efficient ever produced, but they're likely substantially more expensive than the 15% variety (i.e. 3x more efficiency at 10x the cost).

The cheap ones are good for non-concentrating solutions, but the sweet spot for concentrator arrays is somewhere else. If you're using a 300x concentration factor, you only need 0.3 percent of the solar cell area. In that case, since the cell is only a small part of the cost of the solution, if increasing power output by a factor of three (due to increased efficiency) is accompanied by a less-than-threefold price increase, you've won.

Re:The 44.7% efficiency requires 297 suns (3, Interesting)

pla (258480) | 1 year,27 days | (#44967449)

Why is it none of these ever make it to manufacture. Typical solar panels have an average efficiency of 15%, with the best commercially available panels at 21%.

Because as much as I look forward to someday powering my entire house with a handful of 90% efficient solar panels, I care a lot more about the cost per panel at present. If I can afford to pave a quarter acre with 10% efficient panels while these 40%+ ones would bankrupt me - Hey, guess which ones I'll just buy 4x as many of?

Re:The 44.7% efficiency requires 297 suns (2)

BlackPignouf (1017012) | 1 year,27 days | (#44968395)

Give credits to this company.
They have fields in Spain, USA & Israel (http://www.soitec.com/en/products-and-services/solar-cpv/our-references/) with about 25% of system efficiency.
This takes into account optical losses, cell efficiency, module efficiency, module mismatch, inverter efficiency, cable losses, etc etc...
It's not 45%, but it's twice as much as any other PV installation.
Nobody will ever achieve 44.7% system efficiency, but Concentrix does a pretty good job at implementing those cells in their system.
The modules aren't that expensive, because Fresnel lenses are cheap, and the cells are so small (about 1mm).
You need places with very high direct radiation levels and very good 2-axis trackers, though.

Re:The 44.7% efficiency requires 297 suns (0)

Anonymous Coward | 1 year,27 days | (#44968943)

You pulled those percentages from your ass. Basic consumer PV cells are at least 32% efficient.

The single factor preventing large scale PV adoption is the price.

Re:boring (0)

sycodon (149926) | 1 year,27 days | (#44966771)

Let me know when I can buy them at Home Depot.

How much? (0)

Anonymous Coward | 1 year,27 days | (#44965733)

I'd like to get one, but all I have for it is this camouflaged golden gun.

Re:How much? (1)

Virtucon (127420) | 1 year,27 days | (#44965853)

The Laser he used was Solar Powered not the Golden Gun. He was an assassin that used a Golden Gun that shot bullets made of gold. [wikipedia.org] Do you also have three nipples?

Awesome. (0)

Anonymous Coward | 1 year,27 days | (#44965741)

In January they were at 20%. I wonder if Bill Gates is throwing money at them yet.

Re:Awesome. (5, Funny)

Anonymous Coward | 1 year,27 days | (#44966107)

No. But the Saudis are investing in cloud technology.

Re:Awesome. (1)

coolsnowmen (695297) | 1 year,27 days | (#44966955)

Its a good thing the Chinese have been practicing cloud killing technology [reference the Olympics]

Re:Awesome. (1)

wooferhound (546132) | 1 year,27 days | (#44967727)

It would be so cool to get solar power from the cloud . . .

Better than gasoline energy efficiency (2, Informative)

Darth Twon (2832799) | 1 year,27 days | (#44965777)

Thats better than the 25-30% gasoline efficiency. So it sounds good to me! http://en.wikipedia.org/wiki/Engine_efficiency [wikipedia.org]

Re:Better than gasoline energy efficiency (3, Interesting)

InvalidError (771317) | 1 year,27 days | (#44966799)

Not much point in comparing the efficiency of an energy source with the efficiency of an energy sink; they're at the opposite ends of the energy cycle.

Unless you can use your solar-electric power immediately, you also need to add a whole conversion system for storage and discharge which can be quite lossy if you choose electrolysis for energy storage due to much higher energy density than batteries.

To make a fair comparison, you would need to pit two options with similar energy cycle against each other. Something like solar-hydrogen vs solar-biodiesel or solar-ethanol. Growing algae and converting it to biodiesel or ethanol to keep internal combustion engines running might be more efficient overall than electrolysis to produce hydrogen before converting that back to electricity to drive electric motors. Ethanol and biodiesel also have the benefits of well-established distribution channels while high-pressure hydrogen is still scary for many people.

I'm not including plug-in electric since everyone I know seem to be highly skeptical of their operating range and seriously worried about battery replacement costs that can quickly wipe out any fuel savings.

Price dropping, usage growing, rage increasing (5, Interesting)

Maxo-Texas (864189) | 1 year,27 days | (#44965785)

At cleantechnica site you can see a priced drop of $76/w to under $.74 a watt in only (sorta wish it was .76 a watt for neatness sake, dontcha?)

http://cleantechnica.com/2013/05/24/solar-powers-massive-price-drop-graph/ [cleantechnica.com]

You can also see a similar exponential but reverse growth curve off a link from that page.

Elsewhere, I saw solar was projected to generate more energy than the U.S. currently generates by 2050-- and to quintuple from there by 2100.

---

Loved "Mystery Men". On my top 100 list.

Re:Price dropping, usage growing, rage increasing (1)

Virtucon (127420) | 1 year,27 days | (#44965863)

I'm still waiting for a Solar powered Fraculator.

Re:Price dropping, usage growing, rage increasing (4, Insightful)

Firethorn (177587) | 1 year,27 days | (#44965985)

As usual, an XKCD [xkcd.com] comic applies...

You always have to be careful about extrapolation. What looks like exponential growth is unlikely to stay that way as further order effects come into play.

Re:Price dropping, usage growing, rage increasing (1)

khallow (566160) | 1 year,27 days | (#44966427)

He's extrapolating from more than two data points and there's a crude model that explains what's going on. Sure, I don't see anything staying exponential forever, but why think that the trend is going to break right now rather than 50 years from now?

Re:Price dropping, usage growing, rage increasing (1)

Firethorn (177587) | 1 year,27 days | (#44966747)

I'm not saying it's going to break now. I think it'd break(IE level off) before solar alone outstrips all current power generation in the USA.

Also, it takes more than 2 data points to even extrapolate for exponential growth.

Re:Price dropping, usage growing, rage increasing (1)

khallow (566160) | 1 year,27 days | (#44966903)

Also, it takes more than 2 data points to even extrapolate for exponential growth.

Then it's a good thing there's more than two data points there. But let's consider your assertion. One can take the log of the value part of the two data points (which are value-time pairs). Your XKCD link already showed the scientifically dubious but very feasible approach of extrapolating a line from two data points. Exponentiating back to the original values yields an exponential curve.

Hence, you just extrapolated an exponential curve from two points.

Re:Price dropping, usage growing, rage increasing (1)

ChrisMaple (607946) | 1 year,27 days | (#44967115)

If the underlying equation is exp(ct), c=arbitrary, t=time, 2 points suffice to determine a (real-valued, unique) c.

If the underlying equation is b+exp(ct), 3 points are needed to determine b and c.

Re:Price dropping, usage growing, rage increasing (1)

turkeyfish (950384) | 1 year,27 days | (#44967255)

Not if the equation is degenerate and b=c.

Re:Price dropping, usage growing, rage increasing (1)

khallow (566160) | 1 year,27 days | (#44967371)

If the underlying equation is exp(ct), c=arbitrary, t=time, 2 points suffice to determine a (real-valued, unique) c.

There we go.

Re:Price dropping, usage growing, rage increasing (1)

Firethorn (177587) | 1 year,27 days | (#44968283)

Then it's a good thing there's more than two data points there.

Yeah, misread your original post; rereading later I saw the deal. My original point was more along the lines that if you look from the initial cell culture bacterial growth in a petri dish will be a very clear exponential curve - right up to the limits of the dish. I don't think that solar adoption is going to slow anytime soon(other than regular already known swings), it's just that taking it to 2050 and 'more power than the USA currently uses' is a bit far to be extrapolating.

Solar power is not suited for all power needs. For example, making steel/iron from ore it's desirable to use coal in the process to provide the necessary carbon - and the burning of the coal provides enough energy. I'm sure it's possible to produce with 'just enough' coke to provide the necessary carbon without burning it and providing the heat electrically, but that's not really efficient.

Getting back to the op - the new cell is only a bit more efficient, now the question becomes how affordable is it when put into mass production, or can details of it's construction be used to improve cheaper cells? Not to mention that at 200+ suns of concentration you're not going to be putting it on many houses.

Really, it's like electric cars and batteries - nothing wrong with energy storage capacity today, just the expense of the battery. A cheaper battery(per kwh stored) is more desirable in most applications today than one with higher energy density but equal cost per kwh. Research is still valuable though - higher efficiency/density means you need fewer devices to fulfill your needs and it's one of the paths to making things cheaper. A solar cell that's twice as efficient at 50% more cost is 'cheaper' in many ways than what it replaces.

Re:Price dropping, usage growing, rage increasing (0)

Anonymous Coward | 1 year,27 days | (#44968389)

blah blah blah XKCD #605 does not apply here and grandparent's observed exponential growth curve then drop off curve does. (a variant of the just because it rhymes or is witty does not make it correct)

Re:Price dropping, usage growing, rage increasing (1)

patniemeyer (444913) | 1 year,27 days | (#44967499)

What happened in the early 90's that made the price go back up? Is that just noise in the graph? Subsidies dropped?

Well of course (5, Funny)

NoNonAlphaCharsHere (2201864) | 1 year,27 days | (#44965791)

Sure, the Germans get better solar efficiency, they get a lot more sun.

Re:Well of course (5, Interesting)

SternisheFan (2529412) | 1 year,27 days | (#44966269)

Actually, no they don't. I googled "How much sunlight does Germany get" and after disregarding Fox's disinformation links, I found this:

Germany: Your Unlikely World Leader in Solar Power

germany solar leaderThe average day in Germany is cloudy. In fact, Germans see an average of just over 1500 hours of sunshine per year, a bit less than 64 days worth of sunlight. Needless to say, Germany would be one of the last countries you’d expect to be the overwhelming leader in solar energy production. Yet here it is. Germany alone has half of the world’s solar installations and is the third-largest producer of solar cells. Q-Cells, a German company, recently pulled ahead of Sharp as the world’s largest maker of photovoltaic cells. So how did they do it? How could a dreary country like Germany singlehandedly conquer the solar industry?

To find out, one need look no further than the German government’s aggressive renewable energy incentives. In 2000 the Renewable Energy Sources Act was passed, requiring the country’s utility companies to purchase electricity from solar start-ups at rates higher than retail value. Commonly known as feed-in tariffs, these subsidies made it easy for new solar companies to turn a profit. In fact, their profits were pretty much locked in, and companies raced to get started. That’s how in just four years Germany was already responsible for half of solar electricity generated worldwide.

Now, eight years later the country is still going strong. The progressive law is a broad measure attempting to reduce carbon emissions. The goal is to derive a quarter of its power from renewable sources by 2020. They are already ahead of the 12.5%-by-2010 benchmark set by the European Union. Germany already stands tall with 14.2% of its electricity coming from renewable sources.

And the effect of Germany’s solar leadership has resonated globally. Spain, France, Italy, and Greece have installed similar incentive plans. And U.S. states, led by California, have instituted German-inspired incentives such as net metering.

Link: http://solar.calfinder.com/blog/solar-information/germany-your-unlikely-world-leader-in-solar-power/ [calfinder.com]

Re:Well of course (3, Funny)

NoNonAlphaCharsHere (2201864) | 1 year,27 days | (#44966355)

Thank you, Sheldon; that was interesting.

Re:Well of course (1)

SternisheFan (2529412) | 1 year,27 days | (#44966663)

Thank you, Sheldon; that was interesting.

Your welcome, NoNon.

P.S. My mother called me 'Sheldon' once.

But just once.

Re:Well of course (1)

Trogre (513942) | 1 year,27 days | (#44966895)

That solar data just goes to further illustrate that if the Gulf Stream were to ever shift or cease, Europe would be utterly screwed.

Re:Well of course (2)

Neil Boekend (1854906) | 1 year,27 days | (#44968375)

Nope, It would save a fortune on bridges. We would be able to ride across the ice.

Re:Well of course (1)

angel'o'sphere (80593) | 1 year,27 days | (#44968867)

That solar data just goes to further illustrate that if the Gulf Stream were to ever shift or cease, Europe would be utterly screwed.
In what respect?

If the gulf stream changes we likely get more sun ...

The gulf stream mainly only influences temperatures in winter, I would say in summer its effect is rather low (regarding warmth) and causing more clouds.

Re:Well of course (5, Informative)

Solandri (704621) | 1 year,27 days | (#44967479)

Capacity factor for PV solar in the U.S. [epis.com] is about 0.145. That is, if you plop down a 1000 Watt panel angled at your latitude, and measure its power generation for a year, it'll average out to 145 Watts. It incorporates everything - weather, angle of the sun, night, etc. Across the country, it ranges from about 0.185 in the desert southwest, to 0.11 in New England.

From the Wikipedia article [wikipedia.org] , in 2012 Germany had 32.6 GW of installed PV solar capacity, and it generated 28 GWh of electricity. A year is 8766 hours, so that's an average generation rate of 28000 GWh / 8766 h = 3.19 GW. So their PV solar capacity factor is 0.098 (Numerous hits on Google reporting instantaneous generation and generation over 24 hours notwithstanding - those don't matter, only the long-term cyclical average does, a natural cycle of seasons being one year.)

Basically, Germany is a terrible place to install PV solar [wikimedia.org] . The only reason it's viable there is because their green energy initiatives have driven up the cost of their electricity [wikipedia.org] to about $0.34/kWh (vs about $0.20/kWh for France and the UK). Numerous studies put the cost of electricity from PV solar [wikipedia.org] at about 2x-5x the cost from other sources. So normally it wouldn't be cost-effective. But if you raise electricity prices to 3x what it is in the U.S., suddenly PV solar becomes financially viable.

Re:Well of course (2)

angel'o'sphere (80593) | 1 year,27 days | (#44968881)

You simplify to much.

Meanwhile a nice placed solar plant would be cost effective even without the granted feed in tariffs.

This is due to the fact that you can sell your energy at the spot market and the price for energy peaks there regularly far above the feed in tariffs.

Capacity factors ... an invention by wikipedia ... and some guys who gives talks in TV shows ;D

No one in the energy business uses that term, it is completely useless.

Re:Well of course (0)

Anonymous Coward | 1 year,27 days | (#44969025)

Power rates do not remain flat, they increase year upon year. Try factoring prices for the next two decades, and include the massive rise in oil and gas prices as well as the decommissioning of nuclear power plants across the globe. Now you've done that, add in the highly probable "environmental taxes" that are creeping in. It's pretty clear getting as much renewable energy into the power generation equation is going to help keep power pricing lower than it would be otherwise. Now fast forward 50 years.

Free to play - pay to win. (2)

DerekLyons (302214) | 1 year,27 days | (#44967591)

In short, their 'leadership' is artificial and shallow - bought and paid for, and likely only persisting so long as their market remains distorted by law. And your research missed a further distortion - a tariff on non-renewable energy that's used to subsidize renewable energy installations. (Which can then sell their power at the legally mandated above market rates.)

Re:Free to play - pay to win. (0)

Anonymous Coward | 1 year,27 days | (#44968423)

you mean that's used to indicate the huge externalities of non-renewables?

Re:Free to play - pay to win. (2)

kermidge (2221646) | 1 year,27 days | (#44968505)

For a bit of perspective, the only condition where there can be a free market is anarchy. Once there is any rule of law in any political system (difficult to have one without the other, I think; in fact, to define one rather requires the other) there is skewed market because most law is economic law. Even in criminal law the bulk of it involves property in some form. (There is no way to use law to establish a level playing field; the very act of trying prohibits such - someone is always at a disadvantage before the game starts.)

Re:Well of course (1)

DrXym (126579) | 1 year,27 days | (#44968761)

The real reason is their solar panels are not just efficient. They're ruthlessly efficient.

297 Suns? (1)

Nethemas the Great (909900) | 1 year,27 days | (#44965809)

What happens when you only have 1 Sun? Or, more importantly, a fractional Sun since we have this nifty thing called an atmosphere.

Re:297 Suns? (3, Informative)

qval (844544) | 1 year,27 days | (#44965859)

Look at the graph at http://en.wikipedia.org/wiki/Solar_cell_efficiency [wikipedia.org] (about half way down). All the multijunction solar cells are run under concentration ranging up to ~1000 suns (1000:1 focusing of the suns energy). What's really impressive is that they are getting closer and closer to the 86% efficiency limit imposed by Carnot. Just like with Wind (~59% limit imposed by Betz's Law), our solar cells are approaching as good as we can get.

Re:297 Suns? (4, Insightful)

Anonymous Coward | 1 year,27 days | (#44966689)

I do not think pholtovoltaics are limited by the Carnot efficiency, which applies to the conversion of heat to mechanical work in heat engines. The energy stored electrochemically in batteries can exceed the Carnot efficiency, as can fuel cells.

Re:297 Suns? (0)

Anonymous Coward | 1 year,27 days | (#44966911)

You are fundamentally transferring heat from a hot body (the sun), to a cold body (the earth). Unless you can cryo-freeze the solar panels, you cannot beat that 86%.

Re:297 Suns? (1)

FishTankX (1539069) | 1 year,27 days | (#44967657)

Solar panels do not exclusively operate in the infrared spectrum, so i'd be willing to venture a guess that carnot's law doesn't' apply to photovoltaics, but would apply to solar thermal.

Re:297 Suns? (1)

geekoid (135745) | 1 year,27 days | (#44965887)

There specialized cell for solar farms. They will be under a lens.

Re:297 Suns? (1)

timeOday (582209) | 1 year,27 days | (#44965963)

You could use 2x2 cm lenses to focus onto a matrix of 1x1 mm cells underneath... boom, 400 suns. You would need to shift one or the other throughout the day as the sun moves though.

Re:297 Suns? (1)

timeOday (582209) | 1 year,27 days | (#44966053)

Well here you go, I guess you can use a fiber optic funnel [google.com] to collect and channel light down to a cell underneath without aiming anything.

Re:297 Suns? (1)

timeOday (582209) | 1 year,27 days | (#44966155)

OK, here is a more purpose-specific rigid optical concentrator [slashdot.org] from 2009.

Re:297 Suns? (2)

dbIII (701233) | 1 year,27 days | (#44966245)

You do it all with mirrors and thus don't have to make as much smoke.
If that was too confusing, consider that mirrors are a lot cheaper than these solar cells so an array becomes a collection of dishes instead of flat panels.

297 Suns? (1)

Elgonn (921934) | 1 year,27 days | (#44965813)

I don't think we'd care what the efficiency would be if Earth had 297 suns. jk

What's the actual efficiency when used at a single sun? Is this technique only useful with hundreds of mirrors?

Re:297 Suns? (0)

Anonymous Coward | 1 year,27 days | (#44966203)

This specific cell gets its high efficiency when concentrated solar light is shone upon it, instead of unfocussed sunlight. Its a known feature of PV cells, more solar energy, better efficiency ( within reason and thermal limits )

P.S. captcha for this post: spectrum

...again? Oh great. (0)

Anonymous Coward | 1 year,27 days | (#44965845)

How many years before it hits the market? 44.7% is much better than the normal 15% that's flood the market despite the efficiency record constantly being broken.

No mention of economics.... (1)

mark-t (151149) | 1 year,27 days | (#44965901)

Makes me suspect that this is anything but affordable.

Re:No mention of economics.... (4, Informative)

Gravis Zero (934156) | 1 year,27 days | (#44965939)

Multi-junction cells are expensive to produce, using techniques similar to semiconductor device fabrication, usually metalorganic vapour phase epitaxy but on "chip" sizes on the order of centimeters. In cases where outright performance is the only consideration, these cells have become common, they are widely used in satellite applications for instance, where the power-to-weight ratio overwhelms practically every other cost.

Re:No mention of economics.... (1)

Dan East (318230) | 1 year,27 days | (#44966487)

Yet it can still be "affordable" because these are designed to achieve this efficiency at 297 suns' worth of energy. Thus you have 297 cheap 1 m^2 mirrors reflecting sunlight at just a single 1 m^2 solar panel. So if the panel costs less than 297 times the cost of a normal solar panel designed to capture a single sun's worth of energy, it is actually cheaper (not counting cost of mirrors or active hardware to aim the mirrors as the sun moves across the sky, but you get the idea).

Re:No mention of economics.... (1)

MattskEE (925706) | 1 year,27 days | (#44966647)

Multi-junction cells are expensive to produce, using techniques similar to semiconductor device fabrication, usually metalorganic vapour phase epitaxy but on "chip" sizes on the order of centimeters. In cases where outright performance is the only consideration, these cells have become common, they are widely used in satellite applications for instance, where the power-to-weight ratio overwhelms practically every other cost.

MOVPE/MOCVD growth methods are not inherently limited to small chips that are centimeters in size. Researchers might be growing smaller samples during R&D because of limited reactor sizes, and the expense and difficulty of handling large wafers. Once the technology is demonstrated on small wafers the design can be scaled up for growth on larger wafers.

Commercial MOCVD reactors may grow on dozens of small wafers simultaneously in a single chamber, and the wafer sizes can also be increased. Commercial LEDs are grown by MOCVD on 6" wafers, maybe even 8" by now I'm not sure.

Solar cell efficiency graph (4, Informative)

Gravis Zero (934156) | 1 year,27 days | (#44965909)

Here is a graph of solar cell efficiency [wikimedia.org] showing the different kinds of materials used to make them. The typical solar cell [wikipedia.org] is silicon (blue on the graph) and maxes out at 27.6% efficiency.

Re:Solar cell efficiency graph (1)

Anonymous Coward | 1 year,27 days | (#44966035)

To be fair the multi-junction solar cells are basically a sandwich of various semiconductors. The amazing things about the new solar cell isn't some magic doping of silicon but rather they now have the procedure for bonding a bunch of different semiconductors.

Yikes! (1)

linear a (584575) | 1 year,27 days | (#44965921)

The worked with the energy output of 297 suns? Please point that the other way sir.

Re:Yikes! (1)

jcdr (178250) | 1 year,27 days | (#44966243)

Lens

Not another one of these stories (-1)

Anonymous Coward | 1 year,27 days | (#44965941)

After all of the years I've been reading Slashdot, I must have read ~50 of these stories and yet... When you go to buy a solar panel the efficiency is ~10-15%. Slashdot... all of these efficiency stories are just BULL SHIT!!! Lets have a new policy... No stories about solar efficiency until the efficiency is actually attached to a commercial product. Otherwise, all we are getting is SNAKE OIL!!!

Clearly, the editors can be described as gullible.

Re:Not another one of these stories (0)

Anonymous Coward | 1 year,27 days | (#44965977)

But Snake Oil has an efficiency close to 30% - that should count for something.

Re:Not another one of these stories (1)

turkeyfish (950384) | 1 year,27 days | (#44967283)

They used to say the same thing about desktop computers too.

Cost (1)

Anonymous Coward | 1 year,27 days | (#44965971)

Unfortunately these super high efficiency cells are unlikely to ever be very cost effective due to the manufacturing process required. Any efficiency >33.7% (known as the Shockley–Queisser limit) requires combining cells made of different semiconductors with different bandgaps onto the same wafer, which is always going to be substantially more expensive than the plain silicon cells.

The reason for this limit is the basic physics behind how solar cells work: a photon is used to knock an electron in the cell from a low energy band to a higher one. Based on how far apart these bands are (known as the bandgap) only photons above a certain energy level are useful. However, any energy in the photon beyond the bandgap is wasted, as it can't make the electron energy greater than the highest orbital in the atom. Thus there is a balance between picking a bandgap which can capture more photos and one which captures more energy from each photon. As luck would have it, silicon is actually pretty close to optimal (1.1eV when optimal is 1.34eV, giving a max efficiency of 29%).

Another Pointless 'Breakthrough' - (0)

Anonymous Coward | 1 year,27 days | (#44966073)

Let me know when any of these miracle solar technologies have even a vanishingly small chance of being economical. The most likely route for solar technology to take is not in high cost, high efficiency modules, but in low cost, low efficiency modules spread like blacktop over any surface we can find - that is, a terribly untidy but effective rollout that is expensive to install but inexpensive to insure and maintain. Practically all multi-junction technologies rely on rare materials with no known substitutes. They have no economic future except in the most demanding applications, like the space programs they were invented for.

Since these cells also rely on concentrated sunlight, their performance is diminished in diffuse light like what is seen during a cloudy day, eliminating one of the main advantages that photovoltaic technologies have over concentrated thermal technologies. I suspect that the scarcity of the materials used to produce these modules combined with the need for concentrating hardware (and subsequent maintenance of said hardware - that's strike two) will keep them from competing with thermal applications any time soon, which also require concentrating hardware but have no need for expensive, exotic solar cells.

Personally, my money is on dye sensitized photovoltaic technology bringing this type of energy to the masses. No, it will not be efficient, and nobody will care because in time it will be very cheap.

Blah (1)

The Cat (19816) | 1 year,27 days | (#44966141)

Blah blah blaaaaaaah it'll never work blah /thread

what if you put it outside under 1 sun? (0)

Anonymous Coward | 1 year,27 days | (#44966151)

And what if you put it under 1 sun? aka outside?

Rare elements? (1)

manu0601 (2221348) | 1 year,27 days | (#44966515)

Do they need rare elements? TFA does not say a word about it, and it is important: if the answer is yes, then it is not economically viable.

Re:Rare elements? (1)

bloodhawk (813939) | 1 year,27 days | (#44966849)

These are likely to be used in price insensitive installations for now, e.g. satellites, where weight and efficiency count for more than the build cost.

Re:Rare elements? (1)

angel'o'sphere (80593) | 1 year,27 days | (#44968897)

Do they need rare elements? TFA does not say a word about it, and it is important: if the answer is yes, then it is not economically viable.
What a nonsense. Why don't you check prices for rare elements? Or get an idea how abundant they actually are?

The price & efficency of solar cells is irrele (0)

rssrss (686344) | 1 year,27 days | (#44966897)

Solar electricity will never be economical, even if the cells are free and operate at maximum efficiency.

First free cells wouldnâ(TM)t be free. It would still cost thousands of dollars to put them up on a roof. We put a new asphalt shingle roof on our house (a nice suburban house not Algore mansion sized) a few years ago. It cost about $15,000.

I canâ(TM)t conceive of a generating material that would be as cheap as asphalt roofing, which is about as generic and low tech as it gets.

Furthermore the roofing business labor pool is also generic and low tech. Getting licensed electricians involved will only drive up labor costs.

I have not even noodled the price of wiring and the electronics needed to make the low voltage DC output of the cells usable.

Frames and land would be large costs for non-roof systems. Paving material? Around here roads are repaved every few years â" more cost.

Second, solar systems do not operate at night and their output can drop between 50 and 75% on a cloudy day. Every day has a night, and a majority of days around my location are cloudy. There are no economically viable systems for storing large quantities of electricity, therefor every watt of solar you are relying on must be backed up by a watt of something else. These days that is usually natural gas generation. This doubles the capital cost of solar systems.

Third, north of the tropics there is an annual variation in the amount of available solar energy. In my location at 40 north, the ratio between available solar energy in June and the amount in December is about 2.67 to 1. The amount of electricity used does not vary nearly that much. Electricity used for air conditioning in the summer is used for lighting, heating, and cooking in December. We often hear brownout alerts on the coldest days of the winter.

The implication of this is that two thirds of a solar electricity system big enough to supply us in December would sit idle in June, producing no revenue but still carrying a capital cost.

The punch line is that solar electricity is and will remain unaffordable no matter what the solar cell technology is.

Re:The price & efficency of solar cells is irr (3, Informative)

AHuxley (892839) | 1 year,27 days | (#44967173)

It really depends on your local power company NET/FIT rates, federal solar panel import protections and state/city building/code regulations.
Some areas ensure you get real cash back for feed in back to the grid. Others have do not offer so much export cash to homes with solar.
City building/code regulations can also be costly in some areas.
http://freeingthegrid.org/ [freeingthegrid.org]
http://en.wikipedia.org/wiki/Net_metering#United_States [wikipedia.org] vs http://en.wikipedia.org/wiki/Feed-in_tariff#United_States_2 [wikipedia.org]
http://finance.yahoo.com/news/solar-panel-next-granite-countertop-161321343.html [yahoo.com]
http://www.fool.com/how-to-invest/personal-finance/home/2013/09/15/net-metering-how-a-little-known-policy-can-shave-h.aspx [fool.com]
When energy prices going up, you get a FIT, the cost of a solar install in your state is fair, your home has newer appliances... the pay back period is not so unaffordable over years.

Wrong (5, Funny)

Rujiel (1632063) | 1 year,27 days | (#44967261)

Do you get your talking points from a PR firm? Did you seriously just list the price of re-shnging your roof as a reason why solar could never be economical? Even if that were true, you need to think outside of the box, brah. http://cleantechnica.com/2013/05/15/caution-wet-solar-power-new-affordable-solar-paint-research/ [cleantechnica.com]

I find it pretty comic you're listing today's absorption rates as the reason solar "will never" (emphasis on the bolded word) be affordable. What website are you on right now? I wouldn't peg you for a technology enthusiast. Got news for you, bud: technology advances. Solar will become a dominant energy source. It's just a matter of when. You should stop watching cable TV; it's convinced you of silly things, sheltered you in petrol pipe dreams.

Re:The price & efficency of solar cells is irr (1)

Anonymous Coward | 1 year,27 days | (#44967281)

Solar will win, will defeat the Nuclear Industry!

Re:The price & efficency of solar cells is irr (1)

Solandri (704621) | 1 year,27 days | (#44967517)

Solar electricity will never be economical, even if the cells are free and operate at maximum efficiency.

We already have free solar cells. They're called plants. When you burn wood, or make ethanol from cane sugar, you're using solar energy.

That's why IMHO the holy grail of power generation (other than fusion) is cellulosic ethanol. The vast majority of the solar energy plants collect goes into making cellulose. CO2 + H2O + energy => O2 + (CH2O)n. The (CH2O)n is sugar, which plants then string together into (C6H10O5)n which is cellulose. If we can figure out a cheap, scalable way to convert cellulose back to sugar, then ferment it to produce ethanol, we will have effectively turned every plant out there into an ethanol production factory. That solves almost every energy problem we have. It's cheap, abundant, renewable, has high energy density (nearly as much as gasoline, an order of magnitude better than batteries), we already have massive infrastructure in place for transporting and burning liquid fuel, as well as over a century of R&D into engines which combust liquid fuel.

Re:The price & efficency of solar cells is irr (0)

Anonymous Coward | 1 year,27 days | (#44967845)

If we can figure out a cheap, scalable way to convert cellulose back to sugar, then ferment it to produce ethanol, we will have effectively turned every plant out there into an ethanol production factory. That solves almost every energy problem we have.

I dream of a day when I will make money by allowing someone else to cut my grass.

Re:The price & efficency of solar cells is irr (2, Interesting)

Anonymous Coward | 1 year,27 days | (#44967615)

Two years ago I had 10 square metres of solar power put on my roof. Total cost: £15000 (~$20000). These cells have produced 3400 kW/H of electricity over that period. I don't live in the tropics; Latitude ~53 deg north.
Last point: Solar cell prices have fallen over 35% during the last 2 years.
Not phenominal but not irrelevant either

Re:The price & efficency of solar cells is irr (0)

Anonymous Coward | 1 year,27 days | (#44968989)

1. What the fuck is a kilowatt per Henry?
2. At $0.20/kWh your install would pay for itself in about 60 years. Assuming no maintenance cost, no efficiency loss and everlasting inverters. Whoops.

1 uSec (1)

AndyKron (937105) | 1 year,27 days | (#44966973)

"at a concentration of 297 suns"... for 1 microsecond.

Don't Envy Germany's Energy Policy (3, Informative)

rssrss (686344) | 1 year,27 days | (#44967183)

"Germany's Energy Poverty: How Electricity Became a Luxury Good" Spiegel 09/04/2013 [spiegel.de]

German consumers already pay the highest electricity prices in Europe. But because the government is failing to get the costs of its new energy policy under control, rising prices are already on the horizon. Electricity is becoming a luxury good in Germany, and one of the country's most important future-oriented projects is acutely at risk.

Re:Don't Envy Germany's Energy Policy (1)

turkeyfish (950384) | 1 year,27 days | (#44967303)

Another Tea Party dream and Fossil Fuel industry hope. The more solar technology advances and begins to encroach on fossil fuel profits, the more of these "no we can't" nay-sayers come popping out of the wordwork. If solar cells go the way of IC's, the industry will replace fossil fuels entirely in 50 years. The future will be owned by those who invest in solar now. Its inevitable.

So what, nearly 4 watts per square metre? (-1)

Anonymous Coward | 1 year,27 days | (#44967459)

So the incoming solar energy peaks at about 8 watts per square metre, so half of that is 4 watts per square metre. So the south half of my house roof is 10x20 meters, and 200 square meters gives me 800 watts. My house uses (nomianally) 2000-3000 watts, so I would need between 1200 and 2200 watts more than the sun can deliver, during the daytime, on a cloudless day, in the summertime, at noon. I understand that having a roof full of panels can provide a lot of power, but they aren't the full answer (not now or even if we get to 100%), nor is wind. And I already use low power computer cpu's, and led light bulbs. Even my flashlight uses an LED bulb (but its mostly because the batteries last for 290 hours instead of 42 hours, and the light is still white, not dull yellow).

Re:So what, nearly 4 watts per square metre? (5, Insightful)

jandjmh (66714) | 1 year,27 days | (#44967519)

Sunlight at high noon directly overhead is close to 1000 watts per square meter. My neighbor's roof has panels about 2x4 ft (a bit less than a square meter) that are rated at 120 watts output each. Her rooftop array of just a dozen panels provided 100% of her consumption last year, per her net metering annual bill.
It's a very modest sized house, One bedroom, one bath, about 1000 square feet, but it is also a very modest sized array.

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