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New Solar Cell Sets Record For Energy Efficiency

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."

33 of 165 comments (clear)

  1. Better than gasoline energy efficiency by Darth+Twon · · Score: 2, Informative

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

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    1. Re:Better than gasoline energy efficiency by InvalidError · · Score: 3, Interesting

      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.

  2. Price dropping, usage growing, rage increasing by Maxo-Texas · · Score: 5, Interesting

    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/

    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.

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    1. Re:Price dropping, usage growing, rage increasing by Firethorn · · Score: 4, Insightful

      As usual, an XKCD 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.

      --
      I don't read AC A human right
  3. Well of course by NoNonAlphaCharsHere · · Score: 5, Funny

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

    1. Re:Well of course by SternisheFan · · Score: 5, Interesting
      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/

    2. Re:Well of course by NoNonAlphaCharsHere · · Score: 3, Funny

      Thank you, Sheldon; that was interesting.

    3. Re:Well of course by Solandri · · Score: 5, Informative

      Capacity factor for PV solar in the U.S. 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, 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. The only reason it's viable there is because their green energy initiatives have driven up the cost of their electricity 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 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.

    4. Re:Well of course by Neil+Boekend · · Score: 2

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

      --
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    5. Re:Well of course by angel'o'sphere · · Score: 2

      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.

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  4. Re:297 Suns? by qval · · Score: 3, Informative

    Look at the graph at http://en.wikipedia.org/wiki/Solar_cell_efficiency (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.

  5. Solar cell efficiency graph by Gravis+Zero · · Score: 4, Informative

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

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  6. Re:No mention of economics.... by Gravis+Zero · · Score: 4, Informative

    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.

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  7. Re:Awesome. by Anonymous Coward · · Score: 5, Funny

    No. But the Saudis are investing in cloud technology.

  8. Re:297 Suns? by dbIII · · Score: 2

    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.

  9. Re:The 44.7% efficiency requires 297 suns by ShanghaiBill · · Score: 5, Informative

    "...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.

  10. Re:The 44.7% efficiency requires 297 suns by icebike · · Score: 3, Interesting

    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.

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  11. Re:The 44.7% efficiency requires 297 suns by rahvin112 · · Score: 4, Insightful

    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.

  12. Re:297 Suns? by Anonymous Coward · · Score: 4, Insightful

    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.

  13. Re:The 44.7% efficiency requires 297 suns by nbauman · · Score: 4, Funny

    This means that they use mirrors to focus the light onto the panel.

    I know just where to put them.
    http://news.slashdot.org/story/13/09/03/0157256/building-melts-car

  14. Re:The 44.7% efficiency requires 297 suns by notanalien_justgreen · · Score: 3, Insightful

    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).

  15. Re:The price & efficency of solar cells is irr by AHuxley · · Score: 3, Informative

    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/
    http://en.wikipedia.org/wiki/Net_metering#United_States vs http://en.wikipedia.org/wiki/Feed-in_tariff#United_States_2
    http://finance.yahoo.com/news/solar-panel-next-granite-countertop-161321343.html
    http://www.fool.com/how-to-invest/personal-finance/home/2013/09/15/net-metering-how-a-little-known-policy-can-shave-h.aspx
    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.

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  16. Don't Envy Germany's Energy Policy by rssrss · · Score: 3, Informative

    "Germany's Energy Poverty: How Electricity Became a Luxury Good" Spiegel 09/04/2013

    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.

    --
    In the land of the blind, the one-eyed man is king.
  17. Wrong by Rujiel · · Score: 5, Funny

    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/

    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.

  18. Re:The 44.7% efficiency requires 297 suns by pla · · Score: 3, Interesting

    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?

  19. Re:So what, nearly 4 watts per square metre? by jandjmh · · Score: 5, Insightful

    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.

  20. Free to play - pay to win. by DerekLyons · · Score: 2

    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.)

    1. Re:Free to play - pay to win. by kermidge · · Score: 2

      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.)

  21. Re:The price & efficency of solar cells is irr by Anonymous Coward · · Score: 2, Interesting

    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

  22. Re:The 44.7% efficiency requires 297 suns by BlackPignouf · · Score: 4, Informative

    They use Fresnel lenses, not mirrors : http://www.soitec.com/en/technologies/concentrix/components/
    PS: I worked with Concentrix (now Soitec). Cool company.

  23. Re:The 44.7% efficiency requires 297 suns by BlackPignouf · · Score: 2

    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.

  24. Re:The 44.7% efficiency requires 297 suns by DrXym · · Score: 2

    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.

  25. Re:The 44.7% efficiency requires 297 suns by K.+S.+Kyosuke · · Score: 2

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

    What about Deep Space 1?

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