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Power Technology

Solar Panel Breaks "Third of a Sun" Efficiency Barrier 237

Posted by timothy
from the bright-idea dept.
Zothecula writes "Embattled photovoltaic solar power manufacturer Amonix announced on Tuesday that it has broken the solar module efficiency record, becoming the first manufacturer to convert more than a third of incoming light energy into electricity – a goal once branded 'one third of a sun' in a Department of Energy initiative. The Amonix module clocked an efficiency rating of 33.5 percent."
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Solar Panel Breaks "Third of a Sun" Efficiency Barrier

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  • by jmottram08 (1886654) on Saturday November 03, 2012 @04:25PM (#41867151)
    According to wiki this happened in July. Also, for info, they have received over 180 million dollars in grants from the government, and closed their las vegas plant in order to "focus on international opportunities".
  • If you move the panel closer to the Sun, you'll need quadratically less area for the same amount of energy.

    Of course, you'll need a parallel laser beam to send the energy to Earth, and a receptor, etc. but those are left as an exercise for the reader.

  • by tp1024 (2409684) on Saturday November 03, 2012 @04:33PM (#41867219)

    That's just about where the miracles stop reliably. You may or may not find some special cases in which those actually make sense (given that we're talking about concentrated solar and 2-axis drives are mandatory, those cases become even more special), but at large scale it's just not worth it - even without considering the need to store the energy, so you have it when you need it.

  • by SuperBanana (662181) on Saturday November 03, 2012 @04:37PM (#41867251)

    Every 6 months on Slashdot we read about higher efficiency solar panels. Virtually none of them are available on the market, and if they are, they're only available to large-scale commercial installations. Right now, the best you can do retail is about 20%; some panels are barely 10%.

    A condition for any prize should be "available in half-dozen quantities to individual purchasers."

    The best return on investment remains solar hot water - we're talking an order of magnitude in efficiency per area between common solar panels and evacuated-tube hot water collectors. We waste enormous amounts of energy heating hot water and heating homes...

    We'd also save billions of dollars if we stopped selling clothes dryers that are hideously inefficiency; elsewhere in the world condensing dryers are the norm and in some cases dry clothes faster.

    • by Yoda222 (943886)
      Nuclear power plant are also difficult to build from stuff that you can find on the market, and they are only available to large-scale commercial installations.
    • Re: (Score:3, Interesting)

      by Trepidity (597)

      We'd also save billions of dollars if we stopped selling clothes dryers that are hideously inefficiency; elsewhere in the world condensing dryers are the norm and in some cases dry clothes faster.

      I think the prevalence of gas-powered dryers is a reason the U.S. still uses more inefficient dryers, because the fuel (natural gas) is fairly cheap, and much cheaper than with the electric-powered dryers that are prevalent in parts of Europe. So there's less economic incentive to improve efficiency.

      • by Anonymous Coward on Saturday November 03, 2012 @05:55PM (#41867849)

        http://ths.gardenweb.com/faq/lists/laundry/2004120958010854.html

        "All else being equal (i.e. not including household heating/cooling issues), condenser dryers are slightly less efficient than their vented counterparts, typically on the order of ~15%. The real design intent of condenser dryers isn't improved efficiency, but the simple fact that they don't require a vent duct, permitting easy installation most anywhere (ideal for apartment dwellers, etc). "

        A gas dryer is going to be much more energy efficient than an electric dryer considering that ALL the heat generated from the flame enters the tumbler. Typical power plants can only transmit up to ~40%% of the heat from their power source to the dryer heater coils.

        Min energy eff electric: 3.01 lb/kWh
        Min energy eff gas: 2.67 lb/kWh

        Electric is 12% more efficient at point of use

        Total heat efficiency including power generation:
        3.01 * 40% = 1.2
        2.67 * 100% = 2.67

        most efficient setup would be an external venting gas dryer in a unheated space like a basement or garage since you would not be adding load to an HVAC system.

        • by amorsen (7485)

          You are at least 5 years out of date with that information. Traditional condensing dryers are obsolete, modern ones use heat pumps and are vastly more efficient than vented dryers.

          • by jamesh (87723)

            You are at least 5 years out of date with that information. Traditional condensing dryers are obsolete, modern ones use heat pumps and are vastly more efficient than vented dryers.

            Our heat pump dryer is awesome. Expensive, but awesome. Prior to that we were often hanging clothes inside to dry (hanging them outside brings in the pollen which is very bad at this time of year (Spring in AU)). With our one we have to empty out the water tub manually, and it's amazing to see how much water used to be evaporating into the house!!

          • Re: (Score:3, Informative)

            by Anonymous Coward

            OK, some more math

            http://www.topten.info/uploads/File/040_Rita_Werle_final_driers.pdf

            efficiency of heat pump condensing dryer
            best in market (according to report)
            0.23 kWh/kg = 8.15lb/kWh
            worst in market
            0.4 kWh/kg = 5.5lb/kWh
            Euro A grade requirement
            0.48 kWh/kg = 4.58lb/kWh

            efficiency of power generation facilities
            http://www.eia.gov/electricity/annual/pdf/table5.3.pdf
            natural gas = 3412/8185=41.7%
            coal = 3412/10415=32.8% (roughly same as nuke plant)

            distribution losses
            http://data.worldbank.org/indicator/EG.ELC.LOSS

    • by AmiMoJo (196126) *

      At this stage cost a more important factor than efficiency. We have vast amounts of unused space that could be covered in solar PV panels, but the fact that it takes years to recover the investment of thousands of Euros/Dollars is holding back adoption.

    • by Annirak (181684) on Saturday November 03, 2012 @05:18PM (#41867531)

      It looks like I can buy solar modules for a minimum cost of $1/Watt.

      Assume an energy cost of $0.1/kWh. Assume an average of 12 hours of sunlight per day and a 50% of maximum average intensity.
      $0.1/kWh * 1 year / 12 * 50% * 12 hours/24 hours = $0.01826

      The monthly value that a solar cell generates is $0.01826/watt month.

      Assume a yearly interest rate of 5% (monthly is 0.4074%)

      Since the cost of a solar cell is $1/watt, work out the number of months that a 1W solar cell must run for to generate $1.
      PV = A/i (1-1/(1+i)^n)
      PV = $1, A = $0.01826, i = 0.004074

      n = 62 months = 5.17 years

      The warranty on the reference cell is 10 years product workmanship, 25 years linear power.

      So the value of the cell over its 25-year life span is $3.15/watt, with a cost of $1/watt.

      This all neglects installation and grid-tie costs, but 50% average illumination per daylight-hour is conservative in most areas. Solar cells ARE worthwhile TODAY and WITHOUT government subsidies.

      Efficiencies in solar cells are irrelevant. The only thing that matters is the $/Watt.
      Reference Solar Cell: http://www.affordable-solar.com/store/solar-panels/CSI-CS6P-245P-245W-Solar-Panel-STD-Frame

      • by gfxguy (98788)
        I agree with you, and would love to use as much renewable energy as possible and save money in the long run, but I think the problem is that most people in the U.S. do not actually live in their homes for a long enough time. I've been here 13 years, but I've been looking to move for the past five or so (but haven't been able to for various economic reasons). Before the housing market crash, I read the average duration in any one home had shrunk to only about 7 years, so it's not just me. I'd actually lov
        • by Annirak (181684)

          It actually continues to work for you even after you leave. Adding renewable energy generation and high efficiency heating/cooling (geothermal) to your home increases your property value, which gives you the option to do the same again, or buy one with the work already done.

        • by Solandri (704621)

          but I think the problem is that most people in the U.S. do not actually live in their homes for a long enough time. I've been here 13 years, but I've been looking to move for the past five or so

          This shouldn't really matter, as any unrealized value of the PV panels would presumably be recouped by increased resale price of the house.

          The hang-up is up-front costs. The average home in the U.S. uses 11,500 kWh [eia.gov] in a year. So at a constant power draw that's 1311 Watts. Factor in PV solar's average capacity

          • The hang-up is up-front costs. The average home in the U.S. uses 11,500 kWh in a year. So at a constant power draw that's 1311 Watts. Factor in PV solar's average capacity factor o 0.145 and that means you need 9050 Watts of nameplate capacity installed to (on average) zero out your electricity bill (in reality it's a bit less because peak electric prices are during the middle of the day when nobody's home but the panels are generating the most).

            In my region of California, residential electricity costs are tiered, with Tier 3 (starting at 418kWh/month, or about half of the average you stated above) breaking 24 cents per kWh, and continuing to Tier 5, still less than the monthly average usage you quoted, running over 32 cents per kWh.

            Any renewable energy system that can take kWh off the top of that stack will pay for itself in very short order around here.

      • by Solandri (704621) on Saturday November 03, 2012 @07:01PM (#41868285)

        Assume an energy cost of $0.1/kWh. Assume an average of 12 hours of sunlight per day and a 50% of maximum average intensity.
        $0.1/kWh * 1 year / 12 * 50% * 12 hours/24 hours = $0.01826
        The monthly value that a solar cell generates is $0.01826/watt month.

        Average capacity factor for solar in the U.S. is about 0.145. That is, a 100 Watt nominal panel will on average generate 14.5 Watts throughout the year after factoring in everything - night, weather, angle of the sun, etc. In the desert Southwest it's about 0.18 (0.195 in extreme desert regions), but for the country overall it's about 0.145. The NREL assumes a capacity factor of 0.17 [nrel.gov] for PV installations in the U.S., which are predominantly in the desert Southwest.

        Your quick "12 hours a day, 50% max average" assumes a capacity factor of 0.25. Almost twice the actual value.

        Correct for this in the rest of your math and you get n = 120, or 10 years payback. That sounds about right as the test cases I've calculated usually wind up between 7 and 15 years.

      • by ljw1004 (764174)

        So the value of the cell over its 25-year life span is $3.15/watt, with a cost of $1/watt... Solar cells ARE worthwhile TODAY and WITHOUT government subsidies. Efficiencies in solar cells are irrelevant. The only thing that matters is the $/Watt.

        That's interesting. Please also compare:

        * If you invested $1 in the stock market, and see how much it grew in 25 years, minus the cost of the energy you'd need to buy.

        (I suspect that 315% over 25-years is much smaller return than what you'd get from stock market growth).

        • (I suspect that 315% over 25-years is much smaller return than what you'd get from stock market growth).

          Stock market growth roughly matches GDP growth in the country. If you think the country's output is going to grow more than 315% in the next 25 years, then that's a good bet.

          Looking at the future from the way things stand right now, we're in for a rocky few years at least. It is not at all a sure bet that we will manage to get a 315% return over that period, and the stock market could drop more as baby boomers remove their money from the market. Plan accordingly.

      • by pepty (1976012)

        PV = $1, A = $0.01826, i = 0.004074

        n = 62 months = 5.17 years

        The warranty on the reference cell is 10 years product workmanship, 25 years linear power.

        So the value of the cell over its 25-year life span is $3.15/watt, with a cost of $1/watt.

        This all neglects installation and grid-tie costs, but 50% average illumination per daylight-hour is conservative in most areas. Solar cells ARE worthwhile TODAY and WITHOUT government subsidies.

        Efficiencies in solar cells are irrelevant. The only thing that matters is the $/Watt.

        Efficiencies in solar cells are irrelevant - as long as they are constant. The 25 year linear power guarantee is that you will be at 80-90% of the rated power after 10 years, and 60-80% after 25 years. I don't think you will reach a value of $3/watt under those conditions; on the other hand investing that initial dollar at 5% will get you to at least $3.30 by year 25. If you're looking at it as a straight investment proposition I think you need to consider the subsidy vs installation/maintenance/degradation

    • We'd also save billions of dollars if we stopped selling clothes dryers that are hideously inefficiency; elsewhere in the world condensing dryers are the norm and in some cases dry clothes faster.

      You're wrong. If everyone drove half, used 2x efficient appliances, etc it would work until the population doubles. Then we're right back where we started. If they start creating energy from "nothing" like sunlight, we can use all the energy we want at any rate at any population level.

    • by AbRASiON (589899) *

      Wait the condensing ones are more efficient?
      I know they are vastly more expensive to purchase upfront but I was under the impression they are also terribly inefficient, the advantage is they don't mould up the bathroom with a lot of water condensation?

  • by ChumpusRex2003 (726306) on Saturday November 03, 2012 @04:46PM (#41867317)

    Unfortunately, this is a concentrated light solution. This means that the figures quoted for efficiency are in the presence of direct sunlight. However, this is only a proportion of energy generated from PV modules, hence the "efficacy" and therefore, total energy production, of concentrated solar solutions is less good than unconcentrated modules.

    The reason comes from diffuse sunlight - light that has been diffused by the atmosphere or by clouds. This typically accounts for 10% of module illumination in direct sunlight, and much higher in the presence of atmospheric haze/cloud; even in lightly overcast conditions, you can expect unconcentrated PV to yield approx 10-15% of direct illumination yield because of the diffuse illuminance.

    Diffuse light cannot be concentrated by optics, thus concentrated solar PV modules cannot utilise the diffuse light (more precisely, they can utilise it, but not concentrate it - thus if the system uses a 10:1 concentration, then the energy yield from diffuse illumination falls from 10-15% to 1-1.5%).

    A boost from 30 to 33% efficiency by switching to concentrating modules could be completely wiped out by the loss of diffuse yield, even in direct sunlight. In non-direct sunlight, hazy or cloudy conditions, the yield can be reduced much more severely; resulting in a net reduction in productivity, despite the higher nameplate efficiency.

    This technology is most suited to areas with the most intense direct illumination; e.g. dry areas, at low latitudes (where the role of diffuse light is diminished in proportion).

    • by BlackPignouf (1017012) on Saturday November 03, 2012 @05:42PM (#41867733)

      However, this is only a proportion of energy generated from PV modules, hence the "efficacy" and therefore, total energy production, of concentrated solar solutions is less good than unconcentrated modules.

      No. A 2-axis tracked CPV system with multi-junction cells will produce more with beam radiation than a 2-axis tracked monocrystalline PV system with global radiation, at least in the regions where CPV is installed (Spain, Israel, Arizona, ...).
      Sure, it won't work well in Norway.

      The reason comes from diffuse sunlight - light that has been diffused by the atmosphere or by clouds. This typically accounts for 10% of module illumination in direct sunlight, and much higher in the presence of atmospheric haze/cloud;

      Diffuse fraction never falls below 16%. Even a clear, deep blue sky still emits diffuse radiation.

      Diffuse light cannot be concentrated by optics, thus concentrated solar PV modules cannot utilise the diffuse light (more precisely, they can utilise it, but not concentrate it - thus if the system uses a 10:1 concentration, then the energy yield from diffuse illumination falls from 10-15% to 1-1.5%).

      True, but we're probably talking 500:1 concentration, here.

      A boost from 30 to 33% efficiency by switching to concentrating modules could be completely wiped out by the loss of diffuse yield, even in direct sunlight. In non-direct sunlight, hazy or cloudy conditions, the yield can be reduced much more severely; resulting in a net reduction in productivity, despite the higher nameplate efficiency.

      33% has been measured under 850W/m2 direct radiation (nominal operating conditions). Compared to 1000W/m2 global radiation (STC), you get 15% less.
      That's still about 28% of module efficiency. How many single-junction PV modules are there that deliver that much, even in laboratory? None.

      This technology is most suited to areas with the most intense direct illumination; e.g. dry areas, at low latitudes (where the role of diffuse light is diminished in proportion).

      You meant "high altitudes", right?

  • I'd do it tomorrow (Score:5, Interesting)

    by rueger (210566) * on Saturday November 03, 2012 @04:58PM (#41867413) Homepage
    I never seriously looked at solar and other "off the grid" options until investigating a house on an island off Vancouver.

    It was new, purpose built, so had some obvious advantages, but what I took away from it was:
    • All electricity was from solar panels on the roof, with a small generator for backup when running things like power tools.
    • All water was from captured and filter/UVed rainwater.
    • Cooking and refrigeration was propane powered.
    • Woodstove for heating.

    Obviously location and climate matter, but at the end of the day it was a viable and practical option, and one that made economic sense as well.

    Sooner or later some bright government will figure out that by heavily subsidizing the installation of solar in homes they'll a) Develop a very viable industry b) drop solar costs due to volume c) get relected because everyone's electric bills will drop d) boost the economy because the money that was going to the electric company can be spent elsewhere. Now, I'm still a fan of hydroelectricity - if you need to generate electrical without generating CO2 and pollution, and without the no-nukes crowd at your door, there isn't a better way to go.

    • by sribe (304414) on Saturday November 03, 2012 @05:13PM (#41867487)

      Sooner or later some bright government will figure out that by heavily subsidizing the installation of solar in homes...

      That's already being done all over the US--has been for years. Yet solar PV is still barely viable economically, even when the government pays 30-60% of the cost.

      • by drinkypoo (153816)

        Sooner or later some bright government will figure out that by heavily subsidizing the installation of solar in homes...

        That's already being done all over the US--has been for years. Yet solar PV is still barely viable economically, even when the government pays 30-60% of the cost.

        No, heavily subsidizing. Let's see if I've got the correct question. Where is Germany. That is correct, let's see how much they wagered. Germany leads in solar because they lead in subsidies. I have my own issues with subsidies but it seems to have worked in this case. In the US there's too many places and cases where you can't get the subsidy, many of which coincide with some of the best places for solar installations, almost like they intended it.

    • I hate to be *that guy* but in the interest of fairness, while hydroelectric doesn't emit CO2 it does apparently emit a good bit of Methane from algae/sediment. I don't know however whether that's methane emission that is due to hydroelectric or no net increase in Methane from redistribution of methane that would have been released somewhere anyway. But it's something to consider.

      Personally I'm a big fan of the Nukes.

      • by gman003 (1693318)

        But in the further interests of fairness, this is more a feature of the reservoir than the hydro plant itself. So even non-power-producing reservoirs emit methane.

        Also, the methane emissions can be greatly reduced by clearing the area of trees and plant life before filling the reservoir. This brings it down to roughly the level of a natural lake.

    • Now, I'm still a fan of hydroelectricity - if you need to generate electrical without generating CO2 and pollution, and without the no-nukes crowd at your door, there isn't a better way to go.

      You get the "don't destroy the environment by flooding it" people at your door. Seriously, there's a big fight over this topic right now in California over Hetch Hetchy reservoir.

  • by pbjones (315127)

    So if we get past 100%would that create a black hole that sucks in energy for everything around it and ultimately would destroy the earth? Just askin'

    • by jamesh (87723)

      So if we get past 100% would that create a black hole that sucks in energy for everything around it and ultimately would destroy the earth? Just askin'

      With your 150% efficient solar cell, and a light bulb shining on it (that could convert electricity into light usable by the solar cell at more than 66% efficiency, which I think also doesn't exist) you would have a "free energy" machine.

  • by Maxo-Texas (864189) on Sunday November 04, 2012 @01:51AM (#41870449)

    Okay so current panel I bought for $1080 with mounting appears to be producing about $3 of electricity per month. I'll get a $300 credit on my taxes this year.

    It's simple and I just plugged it into an out let and my "kilometer" shows it's producing power.

    But $700/$36 = 19 years.

    It will probably break before it reaches break even.

    However--- if electrical power doubles like it has since the 1980's (5 c/pkwh vs 10cpkwh)

    Then it would pay off it about 12 to 15 years.

    Solar isn't "there" yet.

    And the panel went up from $1080 to $1280 after I purchased it.

    • Solar isn't "there" (Score:4, Informative)

      by YesIAmAScript (886271) on Sunday November 04, 2012 @02:53AM (#41870671)

      Maybe not for you.

      Most states have more expensive electricity than $0.10/kWh.

      Also, most people who have solar go on a time-of-use rate where they can sell back power in the day when electricity is worth more and then buy it back at night when it is cheaper.

      My array will pay back in about 9 years. Less with the tax rebate. And it cost less than $1280/panel installed even before rebates.

      When did you measure the panel? Even at $0.10/kWh it should make a little bit more power than that during the summer. My panels are making about 800Wh a day a piece right now and the days are very short at the moment. They make nearly double this much during the summer months.

      • okay ... so your panels are producing 1.6kwh vs my panel's 1kwh.

        So that's 16 cents a day instead of 10 cents per day. Or about $4.80 per panel per month instead of my $3.00 per panel. So $60 per year instead of $36 per year.

        You say your payoff is 9 years...

        $1280/60 = 21.3 years.
        using a little algebra
        $X/60 = 9.0 years or $540/60 = 7.0 years. Wow, if you seriously got your 1.6khw panels, installation, and inverter for $540 per panel that's a phenomenal deal. You can't get close to that for retail instal

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