A triple victory. The winner of 2011 s test has reason to be

Transcription

1 science & technology modules yield measurement test Highlights Text: Jochen Siemer A triple victory SunPower modules dominate the 2012 PHOTON module yield test, decisively claiming the first three places The results revealed by the PHOTON module yield test 2012 are considerably better than those from the previous year, with the best performance ratio this time beating the previous test s best performer by 4.4 percent An increase in quality due to the large number of new products in the test field which is three times the size of last year s is a significant, but not singular, reason for this positive outcome The dominance of SunPower whose modules took the the top three places initially seems crushing, but a closer look reveals some strong contenders The winner of 2011 s test has reason to be content: it managed to improve on the performance that easily won it last year s first place. Model REC230AE, made by Norwegian solar group Renewable Energy Corp. ASA (REC), generated an annual yield of 1,097.9 kwh per kw on PHOTON s module test field in Aachen, Germany the world s largest of its kind. The total was somewhat higher the year before, at 1,150.4 kwh. But these two figures are not suited to a direct comparison in 2011, the modules could benefit from higher total irradiation. A better figure to compare is the respective ratio between the potential kilowatt hour total and the actual one achieved, which is the performance ratio. This was 90.8 percent for test year 2011, but was, in contrast, 91.4 percent for A top performance at least at first glance. A closer analysis, however, reveals that this improvement brought few benefits. The product that set the bar for the previous PHOTON module yield measurement only reached the 27 th spot this year (see table, p. 80). The performance ratio of the REC module fell well short of the ratio achieved by the current test winner, SunPower SPR-327NE-WHT-D, which exhibited a performance ratio of 95.2 percent. That means that there were another 25 candidates that also trumped last year s champion. This is no reason for the Norwegians to get the blues. The REC230AE is still a good solar 74 February 2013

2 Fotostudio Arnolds e.k. / photon-pictures.com A competitive environment: The PHOTON module test field when the annual measurement began in January module. And yet the decline in its position in the overall rankings clearly demonstrates that the PHOTON module test field is not just being used to collect row after row of dull and bonedry data. With a little pathos, one could speak of preserving industrial history because at the end of the day, this technology will be an important, and probably even an indispensable, mainstay of our energy supply in the near future. The rapid improvement in the means of production is both pleasing and highly significant. Tripling the test field The sober facts of the situation need to be addressed first, however. A first, and immediately apparent, reason for the upheaval in the rankings is the growth this outdoor test has undergone: In 2011, the annual yield could be determined for 46 types of modules. A further 77 candidates underwent some testing in 2012 but were added over the course of the year, so no annual yield was obtained. This year, however, annual yield results for these 77 modules are now available. An February

3 science & technology modules yield measurement test Frank Schuberth / photon-pictures.com Ample growth: More than 100 new types of modules were added to PHOTON Lab s outdoor test field over the course of additional 32 types of modules arrived on the test field just in time for installation in January These modules were also included in the 2012 annual assessment. Because a total of four modules could not be subjected to testing for technical reasons (see box, p. 79), a total of 151 candidates remain for which the performance ratio could be determined for In comparison to the previous test, the size of the field of participants has more than tripled. Next year, to clarify this from the start, growth is expected to continue, but not quite as dramatically as it did last year: Currently there are 187 different types of modules being tested on the field, minus the occasional problematic case that experience has shown to be unavoidable. That means, in 12 months time, there will be around 180 candidates vying for the best annual yield. One manufacturer in particular was clearly able to stake its claim to be the best in 2012: Sun- Power Corp. sent three modules in for testing in January 2012 and these three modules took first, second and third place in the annual assessment. With performance ratios ranging between 94.8 and 95.2 percent, the SunPower modules seem to have entered a new dimension, beating REC s top mark of 90.8 percent achieved last year by 4.4 percentage points. However, the situation is not quite as clear-cut as it might seem after all, even the REC230AE improved significantly in the current test, with a performance ratio of 91.4 percent. And all other modules that underwent testing in both 2011 and 2012 followed suit. A number of them even managed much more substantial improvements than last year s winner: The SLK60P6L 230Wp made by Spanish manufacturer Siliken SL, which took second place after the REC module in 2011 with a performance ratio of 86.9 percent, enhanced its performance by 3.1 percentage points to arrive at 92.7 percent which ultimately only earned it 8 th place. Other candidates that took the spots behind the REC module in 2011 and were able to beat it in 2012 include the CSG180S1-35/36 made by CSG PV Tech Co. Ltd., the NT-125AX from Nexpower Technology Corp., the Sunmodule Plus SW 225 mono made by SolarWorld AG and the Aleo S_ from Aleo Solar AG. Speaking of»approximately«the reason for the generally higher performance ratios in test year 2012 in comparison to 2011 is, above all, a consistent policy of noninterference: the modules were neither cleaned nor cleared of snow. In 2011 they were therefore subjected to a longer period of snow cover than in The irradiation sensors, in contrast, which are used to record the available quantity of sunlight, are not as severely affected by these conditions. The performance ratio in years with more snow or what is considered a lot of snow in Aachen therefore changes to the disadvantage of the test candidates. Furthermore, total irradiation is, of course, never just total irradiation: Even when the numerical figure for irradiation is exactly the same in two different years something that is unlikely it is still produced in different ways. Ideal weather for solar modules, which means lots of sunlight at low temperatures, is rather rare. The proportion of hot, sunny days on which modules with low temperature coefficients have an advantage compared to the proportion of days with cloudy weather on which modules with a good weak light response do better will always vary. So weather will sometimes help one product and sometimes another to achieve better results. This is exactly why an evaluation of quality not only has to include the decisive factor performance ratio, but also logging the weak light behavior and homogeneity (see article, p. 84). Movements in the ranking are also the result of the simple fact that even measurements recorded exactly to the second and using highquality equipment are still not absolutely precise. The measuring tolerance is, in terms of the module test device, 1.8 percent. This is a maximum value, and it would be a highly improbable 76 February 2013

4

5 science & technology modules yield measurement test coincidence should all deviations exhaust the tolerance in one direction or the other. However, differences in the performance ratio of various test candidates that are limited to +/-0.5 percentage points may or must be assessed as approximately the same result. Even if the word»approximately«is the last one anyone wants to hear at the test bench. Obviously this does not change PHOTON Lab s claim that its module yield measurement is not only the world s largest, but also the most detailed, test series of its type. And it changes nothing about the clear victory achieved by the SunPower modules. After all, even the last of the winning SunPower threesome beat out the closest competition the SRP-220-6PB made by Seraphim Solar System Co. Ltd. by 1.2 percentage points. Does this make the dark black SunPower cells an unrivaled product? Quality is a question of price Manufacturers of the top-ranking modules would, understandably, be more than happy to interpret the test result in this way; however, there are of course a number of arguments to the contrary. The performance ratio is the text continues on p. 83 Gathering data: Each module generally three specimens for each test product is fitted with a meter that records the IV curve once every second. Guido Schiefer / photon-pictures.com 78 February 2013

6 Unassessed modules The modules that remain unassessed in the PHOTON International module yield measurement for 2012 are those 27 products that have not completed a full year of testing. There are also a number of cases in which a punctual start to testing still failed to result in a complete evaluation. We are currently having problems with all our CIS modules, as the measurement of their performance under STC (standard testing conditions) has not been clearly defi ned. This is due to the fact that the output from a CIS module changes with the amount of time it is exposed to the sun it does, in fact, increase. Because the STC measurement does not include how long and to what intensity of light a CIS module has been exposed before tests begin, it is not possible to compare the STC values specifi ed by the manufacturers. An STC value measured by PHOTON Lab must defi ne how long the module has already been exposed to the sun at the time of measuring. We are currently discussing this matter with CIS manufacturers but have still not arrived at a fi nal decision. We will be addressing this topic in one of the upcoming editions of PHOTON International. This mainly concerns the two CIS module types Shell PowerMax Eclipse 80-C and Solibro SL1-95. Two other types of modules Latitude P6-60/6 (235) and Mage Powertec Plus 230/6PO exhibited signs of potential-induced degradation (PID). Because the modules on the test fi eld are not connected in series, the high potentials against ground that cause this phenomenon are usually avoided. The two module types affected were able to be»repaired«by temporarily applying positive high voltage or grounding them on the negative side. However, an analysis of the annual yield suitable for comparison with those made on the rest of the test fi eld could not be made. These modules had already been removed from the evaluation in 2011 following the sudden occurrence of power losses (see PI 2/2011); however, at the time the PID explanation remained undetected. Also remaining unevaluated is the YL260C-30b (Panda) produced by Yingli Green Energy. The»Panda«solar cells used in the module have (just like the back contact cells from SunPower) a significantly higher capacity than other crystalline solar cells. For these cells, the standard test device that PHOTON Lab developed for yield measurements is too imprecise. The time in which the measuring unit delineates the IV curve is, at 20 to 30 milliseconds, far too short. This makes the values measured a rather low estimate. In order to measure high-capacitive modules, a new measuring unit has been developed. This unit has recently been used on the SunPower modules for the very first time. It will now also be used for the Panda cells, allowing them to be included in next year s evaluation. Incidentally, the fi rst results are highly promising. Even a cautious estimate suggests the Panda modules will seriously test SunPower s dominance. js Visit us Inter Solar 2012 Germany Booth No A3/140 UE Solar Co., Ltd. Add: 15F, Changfa Building 5, Yanzheng Middle Road, Wujin District, Changzhou, Jiangsu, , Tel: Fax: sales@uesolar.com February

7 science & technology modules yield measurement test PHOTON Lab s outdoor module tests: Results of 2012 yield measurements Rank Manufacturer Model Production dates* 1 Installed in Yield in kwh/m² Performance ratio Yield in kwh/kw Deviation from test winner (%) 1 SunPower SPR-327NE-WHT-D % 1, SunPower SPR-320NE-WHT-D % 1, % 3 SunPower SPR-245NE-WHT-D % 1, % 4 Seraphim Solar System SRP-220-6PB % 1, % 5 Yingli Green Energy YL240P-29b % 1, % 6 ET Solar ET-P % 1, % 7 Sunerg Solar XP 60/ % 1, % 8 Siliken SLK60P6L 230Wp % 1, % 9 Jinko Solar JKM190M % 1, % 10 Huanghe HH230(30)P % 1, % 11 Jinko Solar JKM235P % 1, % 12 Apollo Solar 235G6M % 1, % 13 CSG PV Tech CSG180S1-35/36* % 1, % 14 NexPower Technology NT-125AX* % 1, % 15 Linsun Renewable SK60P % 1, % 16 Huanghe HH190(36)M % 1, % 17 Nelumbo NEI 230-3VA % 1, % 18 Schott Solar* 15 SCHOTT PERFORM Poly 235 Since % 1, % 19 Conergy Conergy PowerPlus 235P % 1, % 20 SolarWorld Sunmodule Plus SW 225 mono % 1, % 21 Upsolar UP-M220P % 1, % 22 Aleo Solar Aleo S_ % 1, % 23 ZN Shine PV-Tech ZX250(48)MS % 1, % 24 CNPV Solar CNPV-240P % 1, % 25 Himin Clean Energy HG-190S/Ba % 1, % 26 REC Premium 210 Until % 1, % 27 REC REC230AE* % 1, % 28 Win Win Precision Winaico WSP-250P % 1, % 29 Chint Solar / Astronergy CHSM5612M % 1, % 30 V-Energy VE260PV % 1, % 31 Hareon Solar HR-230P-18/Bb % 1, % 32 Solar Modules Nederland TC245-MO % 1, % 33 Kinmac Solar* 13 KSS-6P6A % 1, % 34 Kioto Photovoltaics KPV 210 PE* % 1, % 35 BP Solar BP 3220 T Until % 1, % 36 Solon SOLON Blue 230/07(225) % 1, % 37 ITS Innotech Solar EcoPlus ITS220ECU5* % 1, % 38 SolarWorld Sunmodule Plus SW 245 poly % 1, % 39 Amerisolar AS-5M-190W % 1, % 40 Win Win Precision Winaico WSP-235P % 1, % 41 REC REC230PE % 1, % 42 Eurener PEPV % 1, % 43 CNPV Solar CNPV-220P % 1, % 44 Sunlink PV SL220-20M % 1, % 45 CH Solar CH Solar 180 mono* 2 Until % 1, % 46 Sunergy CSUN260-60M % 1, % 47 Amerisolar AS-6P30-230W % 1, % 48 CNPV Solar CNPV-185M % 1, % 49 Upsolar UP-M180M % 1, % 50 M-Prime M 235P % 1, % 51 Sunflower Light SF125x M(180) % 1, % 52 Risen Energy SYP185S-M % 1, % 53 PV Power Technologies PVQ % 1, % 54 SWAT-International SWAT-240-PS % 1, % 55 Bisol BMU-215-2/ % 1, % 56 Conergy Conergy PowerPlus 220P % 1, % 57 CEEG Solar* 5 SST M % 1, % 58 Sunergy CSUN250-60M % 1, % 59 Linuo LN180(36)M % 1, % 60 JCS Solar* 11 JCSM290M-72* % 1, % 61 Galaxy Energy GS260m % 1, % 62 Mage Solar Mage Powertec Plus 225/6PJ Until % 1, % 80 February 2013

8 PHOTON Lab s outdoor module tests: Results of 2012 yield measurements Rank Manufacturer Model Production dates* 1 Installed in Yield in kwh/m² Performance ratio Yield in kwh/kw Deviation from test winner (%) 63 CEEG Solar* 5 SST P % 1, % 64 Axitec AC 236P/156-60S Until % 1, % 65 SolarWorld Sunmodule Plus SW 225 poly % 1, % 66 Solaria Energía S6P2G % 1, % 67 CSG PV Tech CSG230M2-30* % 1, % 68 Trina Solar TSM-180DC % 1, % 69 Trina Solar TSM-225PC % 1, % 70 Ningbo Solar Sun Earth TDB125x P 180W* 2 Until % 1, % 71 Vikram Solar ELDORA % 1, % 72 Mage Solar Mage Powertec Plus 230/6PH-US % 1, % 73 Daqo New Energy DQ235PSCa % 1, % 74 Magi Solar MGSM-295-D % 1, % 75 Eging Photovoltaic Technology EGM % 1, % 76 Linuo LN240(30)P % 1, % 77 S-Energy SM-220PA % 1, % 78 Bosch Solar Bosch c-si M % 1, % 79 Frankfurt Solar FS215W-POLY % 1, % 80 Zentralsolar Deutschland Genius SDM % 1, % 81 Hanwha SolarOne* 9 SF M175 (scac) % 1, % 82 Topray Solar TPS105T-180W % 1, % 83 BP Solar BP 3280 T Until % 1, % 84 Bisol BMU-215-2/ % 1, % 85 Talesun Solar TP572M % 1, % 86 Solarwatt M GET AK (230) % 1, % 87 Solarbest Energy-Tech ZSB M % 1, % 88 Jinko Solar JKM255M % 1, % 89 Kenmec Mechanical TKSA % 1, % 90 Fluitecnik FTS-220 P % 1, % 91 Runda PV RS230P % 1, % 92 Suntech Power STP205-18/Ud % 1, % 93 Magi Solar MGSM-240D % 1, % 94 Sunrise Solartech SRM 180D72-GE % 1, % 95 Yingli Green Energy YL210P-29b % 1, % 96 Lilie Energie Lilie SPL % 1, % 97 SolarWorld Sunmodule Plus SW 210 poly* % 1, % 98 Zytech Engineering ZT 230P % 1, % 99 Solargate SG % 1, % 100 Topsolar Green TSM72-125M-190W % 1, % 101 Upsolar UP-M185M % 1, % 102 CNPV Solar CNPV-240M % 1, % 103 Sonalis* 14 SL-180CE-36M % 1, % 104 Scheuten Solar Multisol P % 1, % 105 Sunergy CSUN240-60P % 1, % 106 Sunage SAM 96/ % 1, % 107 Ningbo Solar Sun Earth TDB125x P 160W* % 1, % 108 Chint Solar / Astronergy CHSM-6610P % 1, % 109 Ferrania Solis AP % 1, % 110 Hanwha SolarOne* 9 SF M % 1, % 111 Sunpeak / Alpexsolar* 4 ALP235W* % 1, % 112 Jetion Solar JT230(30)P1655x % 1, % 113 Alex Solar ALM-190D % 1, % 114 CNPV Solar CNPV-190M % 1, % 115 Aide Solar AD195M5-Aa % 1, % 116 Helios Technology H3A230P % 1, % 117 Luxor Solar LX-185M/ % 1, % 118 Axitec AC-250M/156-60S % 1, % 119 Lilie Energie Lilie SPL 185-I % 1, % 120 Evergreen Solar ES-E-210-fc % 1, % 121 Win Win Precision Winaico WSP-230P % 1, % 122 Shell Solar (now with SolarWorld) Shell SQ 150-C* 2 Until % 1, % 123 Solar-Fabrik Premium L poly (225) % 1, % 124 Day4 Energy Day4 48MC % 1, % February

9 science & technology modules yield measurement test PHOTON Lab s outdoor module tests: Results of 2012 yield measurements Rank Manufacturer Model Production dates* 1 Installed in Yield in kwh/m² Performance ratio Yield in kwh/kw Deviation from test winner (%) 125 Sharp NU-185E % 1, % 126 Evergreen Solar ES-A-210-fa % 1, % 127 Perfectenergy PEM-180/185-72M-SCC % 1, % 128 Hanwha SolarOne* 9 SF160 M5-24 (175 W)* % 1, % 129 Kyocera KD210GH-2PU % 1, % 130 Sonalis* 14 SL-190CE-36M % 1, % 131 First Solar FS % 1, % 132 Emmvee Photovoltaics ES-230P60* % 1, % 133 Schott Solar* 15 SCHOTT POLY TM % 1, % 134 IBC Solar IBC MonoSol 240 TT Until % 1, % 135 Suntech Power STP190-18/Ub* % 1, % 136 Sovello SV-X-205-fa % 1, % 137 Calrays CPM 250-A % 1, % 138 Solar-Fabrik SF 130/4-130* % 1, % 139 Evergreen Solar EC-120* % 1, % 140 Sovello SV-X-200-fa* % 1, % 141 Canadian Solar CS6A-170P 2007 (purchased) % 1, % 142 Sunways MHH plus 190 (190 Wp)* % 1, % 143 Solar-Fabrik SF 145A* % 1, % 144 Isofoton IS-170/24* % 1, % 145 Isofoton I-110/24* 2 Until % 1, % 146 Kyocera KC170GT-2* 2 Until % % 147 ASE (now with Schott Solar) ASE-300-DG-FT (300 W)* % % 148 BP Solar BP 7185 S* % % 149 Photowatt International PW W 2005 (purchased) % % 150 Evergreen Solar ES-180-RL* % % 151 Sharp NT-R5E3E* % % * 1 when date of production was unavailable, the date when PHOTON Lab bought the module was used (if possible) * 2 no longer manufactured * 3 referred to as Pure Power SV-X-200 (LV) in previous issues * 4 manufactured by Alpexsolar; available through Sunpeak-Vertrieb Unternehmensgruppe Ratio-Data * 5 CEEG is the manufacturing company of license holder Sunergy * 6 previous model designation: CSG180S1-35/1589x807 * 7 previous model designation: CSG230M2-30/1640x992 * 8 previous model designation: ES-200-P60(230) * 9 previously manufactured by Solarfun Power Holdings Co. Ltd. * 10 previous model designation: Economy New ITS220ECU5 * 11 previous manufacturer designation: JZ Solar * 12 previous model designation: JZM 290M-72 * 13 company has changed its name to Inventec Energy * 14 manufactured by Ningbo Qixin Solar Electrical Appliance Co. Ltd. * 15 company has withdrawn from crystalline silicon PV manufacturing * 16 previous model designation: SW 210 poly 82 February 2013

10 Model:SolarPond 240HF-US Company takeovers, rebrandings and bankruptcies Our editorial office has become aware of a number of insolvencies affecting manufacturers represented in the PHOTON module yield test. Some of these manufacturers have already stopped production, and the survival of others is not guaranteed: Evergreen Solar Inc. August 2011, succeeded by Evergreen Solar () Co. Ltd. Fluitecnik SA January 2013 Siliken SL January 2013 Solar Modules Nederland BV May 2012 Sovello GmbH May 2012, production ceased in August 2012 The following companies will continue operating following an insolvency filing, have been taken over by other companies or were created by takeovers: Hanwha Q-Cells GmbH Insolvency of Q- Cells SE in April 2012, takeover by Hanwha Group with operations to continue as Hanwha Q-Cells GmbH Photowatt International SAS Insolvency in November 2011, takeover in March 2012 by EDF ENR Scheuten Solar Systems BV Insolvency in February 2012, takeover by Aikosolar, operations to continue as Scheuten Solar Solutions BV Solarwatt GmbH Self-administered insolvency in June 2012 (as Solarwatt AG), restructuring and operations to continue as Solarwatt GmbH Solibro GmbH Takeover by Hanergy Solon Energy GmbH Insolvency (as Solon SE) in December 2011, takeover by Microsol in March 2012, continuing operations as Solon Energy GmbH Sunways AG Takeover by LDK Solar in January 2012 js decisive criterion for the technical quality of a solar module, and yet technology is not the measure of all things. Long-term stability is equally significant for a product that needs to function well for at least 20 years. There is little to say about the SunPower modules in relation to this point, as they have, after all, only been on the test field for one year. A candidate like the Siliken SLK60P6L 230Wp has earned considerably more merit in this regard, having been installed on the test field since 2009 and having continued to perform well. And yet it is no longer being manufactured, just like modules made by many other candidates a fundamental problem in long-term tests of products that are seldom produced for more than 2 or 3 years. The results are still interesting, as the successor solar module series usually feature similar technology. And there is also hope that manufacturers that manage to make a good module have not forgotten how to do so when they start making their newest products. In the case of Siliken, there is, however, an additional problem: the Spanish manufacturer has been beset with financial problems insolvency proceedings started at the end of January. By this point at the latest, economic considerations start to emerge that no test field in the world can take into account. In the best case scenario, as occurred in this year s annual evaluation, the ratio of yield to surface can be determined this indicator can be used to determine the value of a solar module when the space available for a planned array is either very expensive or severely limited. All the same, a factor of 2.5 forms the midway point between the poorest value in this discipline 87.7 kwh per m2 in 2012 for the Nexpower s thin-film module NT-125AX and the module with the best result a SunPower module that achieves to kwh per m2. However, surface-related costs such as property, mounting system or cables would have to represent an exorbitant expense to exceed the difference in price between a thinfilm solar generator and SunPower modules. In comparison with other crystalline products offered at much cheaper prices, the situation looks quite different. And this would describe the last quality criteria, one that also cannot be determined on the test field: the price. To exemplify this, the two test winners in 2011 and 2012 need to be examined again. The difference in the performance ratio values determined for the SunPower SPR- 327NE-WHT-D and the REC230AE totals 4.4 percent. Assuming they feature comparably good properties when it comes to durability, the difference in price between these two modules should not be any larger than the difference in performance ratio although one might also add an extra bonus for the better surface yield. Further information Contacts page 142 February

11 science & technology modules yield measurement test photon-pictures.com Non-interference: The modules on the test field are not cleared of snow and are not cleaned. Text: Jochen Siemer A module s fingerprint The large table showing an overview of the PHOTON module yield tests reveals a wealth of compactly presented knowledge about each and every test candidate. How should the figures and diagrams be interpreted? Highlights The PHOTON module yield measurement for 2012 involved comparing 151 types of modules with each other producing the world s largest and most detailed analysis of its type The table being presented over the following pages shows the yield as a numerical value, in addition to diagrams showing the characteristics of each test candidate A»fingerprint«provides insight into a module s reaction to diverse weather situations, also largely revealing why the module performs well, or poorly, in the yield comparison The most decisive factor in the PHOTON module test is, obviously, the yield obtained over the course of a year, measured in kilowatt hours per kilowatt of output (kwh/ kw). It is directly proportionate to the performance ratio, expressing the relationship between the power yield that is theoretically possible (factoring the efficiency in) and the power yield that was actually obtained. Given the irradiation actually available on the module test field in Aachen over the year 2012, a total of 1,202 kwh/kw would have been possible. A module with, for example, an efficiency of 20 percent would have equaled this sum, providing it consistently exhibited the aforementioned efficiency of 20 percent. In practice, and depending on the prevailing conditions (irradiation, temperature and light spectrum), the actual efficiency determined under standard test conditions (STC) usually remains unequaled, and is very rarely exceeded. This is why not one single test candidate reached 100 percent; however, this year s test winner, Sun- Power s SPR-327NE-WHT-D module, with its annual yield of 1,144.1 kwh/kw and its performance ratio of 95.2 percent, did in fact come quite close. The other end of the scale or number 151 in the rankings was bookended by the (no longer in production) NT-R5E3E from Sharp, with kwh/kw and a performance ratio of 79 percent. 84 February 2013

12 February

13 science & technology modules yield measurement test The difference between the two key indicators,»yield«and»performance ratio,«is found in their comparability: the yields from various modules only ever result in a statement applicable for one respective year at the same location (because 1,000 kwh/kw are, of course, a different result in a year with poor sunlight than in one with good sunlight), while the performance ratio values allow several successive years to be compared with each other by showing how the values relate to the irradiation available in each year. This, however, is also subject to limitations, because an annual irradiation total of, for example, 1,000 kwh per square meter, can accrue in different ways, which suits the diverse properties of the various modules differently, for better or for worse. A small table and a large table To allow relationships like this to be assessed better, the analysis of the PHOTON module yield measurement 2012 does not just include a basic ranking sorted according to performance ratio (see table, p ), but also a large table, beginning on p. 89, that presents the test outcomes in more detail. The large table also includes values for modules that have not been installed on the test field for a full year. The informative value of those results is, by nature, somewhat limited. Furthermore, specifying the performance ratio of these modules would not be particularly informative, which is why it does not appear. Only when the next analysis appears in our February edition in 2014 will it be known how the new modules on the test field actually performed. For each candidate including the new ones the large table includes two diagrams alongside the data on the module and measurements. The first, titled»weak light performance,«will already be familiar to PHOTON International readers from last year. This diagram illustrates the irradiation-dependent efficiency, or the module s response under varying irradiation conditions. It also shows the performance ratio at differing irradiation values at the module level. The measurements are taken in the solar simulator, and are therefore not based on the length of time the module has been installed in the outdoor test field. Those who compare the various curves with each other will soon notice a general trend: the higher the module s»starting point,«or its performance ratio at low irradiation, and the more uniform its progress, the better its placement in the rankings. Given the green light The diagram showing»homogeneity«is new this year. It breaks the module performance down into various combinations of solar irradiation and temperature. Viewed from bottom to top, the diagram shows the temperature in increments of five degrees (from to C), from left to right, the irradiation in 100 W increments (from 50 to 1,050 W per m2). Each of the 90 squares stands for a specific combination of irradiation and temperature. The bottommost square at the left indicates very cold and dull weather, with the one at the right, in contrast, also indicating very cold weather, but in this case, also extremely sunny conditions. This weather did not, however, materialize at the Aachen location last year, which is why the diagram showing all modules that completed a full year of testing feature five gray squares at the bottom right. Among the modules that were only added over the course of the year, the number and position of the gray field depends on the time at which they started the test: for a module added in April, for example, there are only 19 gray boxes, while one added in November features 58 gray boxes instead. 86 February 2013

14 The color of the squares, in turn, stands for the respective performance ratio attained by a module: red indicates a low value (60 percent), green represents a high value (110 percent). If a field is marked with a cross, then the performance ratio was off the scale. A red field with a cross therefore stands for less than 60 percent, while a green field with a cross indicates more than 110 percent. A performance ratio of more than 100 percent results when the efficiency determined under STC conditions is exceeded in certain irradiation conditions, for example in very cold, but very sunny, weather. The homogeneity diagrams were drawn up on the basis of values recorded on the PHOTON International module test field once every second for the whole year, this being the current/voltage (IV) characteristic curve for a module, which is the product of the current output, the irradiation and the temperature. To eliminate the effects of short-term fluctuations in weather (for example when cloud cover suddenly retreats), only those weather scenarios were assessed in which the relative standard deviation from temperature and irradiation over the preceding two minutes was less than 0.5 percent. This allowed a specific»fingerprint«for each and every module to be determined. photon-pictures.com (3) The weather at the Aachen location: the»fi ngerprint«shows the weighted distribution of the diverse combinations of temperature and irradiation. The scale ranges from to C, divided into fi vedegree increments going from bottom to top. From left to right, the scale ranges from 50 to 1,050 W per m², broken down in 100 W increments. The square at the bottom left therefore indicates a range of to -7.5 C and 50 to 150 W per m², while the square at the top right indicates a range of 27.5 to 32.5 C and 950 to 1,050 W per m². One of the reasons SunPower s SPR-327NE-WHT-D module reaches a very high performance ratio of 95.2 percent is because its»fi ngerprint«exhibits many high values (marked in green). The module also copes with the Aachen location very well. A particularly high homogeneity indicator is, in contrast, no guarantee for good yields: the HG-190S/Ba from Himin Solar, for example, has a very high value of 12.1 because it operates uniformly under all weather conditions. However, despite a performance ratio of 91.4 percent, the module only comes in at 25 th place. The winner of the test, a SunPower module, has an indicator of only 8.0, and operates less uniformly but at a higher level. February

15 science & technology modules yield measurement test The ideal test The weather in Aachen can be analyzed in the same way: if this involved breaking down the frequency of diverse combinations of irradiation and temperature into 90 squares, as was done for all the test modules, this would only show half the story. This is why the individual combinations are weighted according to irradiation: 50,000 seconds with 1,000 W per m2 are given the same weighting as 500,000 seconds with 100 W per m 2. Furthermore, in contrast to the module fingerprints, fluctuating weather conditions have not been eliminated; every single second of the year has therefore been incorporated into the assessment. This is also the reason why only four squares are shaded in gray for the fingerprint indicating the weather in Aachen in 2012 and not five, as was the case for the modules tested over this period. The position of the green squares in the weather fingerprint indicates which conditions are the most important for a solar module installed in Central Europe: temperatures between approximately 7.5 and 17.5 C at low irradiation of up to around 300 W per m 2 are of just as much significance as the range of temperatures between 12.5 and 22.5 C at irradiation levels between 850 and 1,050 W per m 2. This is a significant factor for the outcome of this year s yield comparison. The homogeneity diagram showing the three SunPower modules, which so clearly dominated the field, is perfectly compatible with the weather in Aachen. The homogeneity indicator for the SPR-327NE-WHT-D of 8.0 (in the»test data«column of the table) is, in contrast, far from a peak value: other modules operate significantly more uniformly and boast indicators of up to 12.1, which is, however, of little benefit when this occurs at an excessively low level. And yet a high level of homogeneity is a worthwhile target. If the PHOTON International test array was, for example, located far further north, where median irradiations frequently occur at very low temperatures, then the performance of the SunPower modules would be less impressive in the yield comparison, because other modules deliver considerably better results under those conditions. In the range of high temperatures of up to 32.5 degrees, in contrast, the SunPower test modules need not shy away from a comparison as their good temperature coefficients also gave reason to suspect. They would also be likely to perform very well in locations further south, at which considerably higher temperatures play a larger role for the overall yield. Arithmetically, at least, the following question can be answered: the yield data determined by PHOTON in Aachen, Germany, could, in combination with the weather fingerprint at a different location, allow a good estimate to be made about what yield a solar module is capable of producing there. However, this also involves two limitations: when temperatures and irradiation values that do not occur in Aachen at all are all too frequent at the hypothetical module location, the estimate will obviously become less reliable. And along with these two factors, there are other factors that also play a role, in particular the spectral distribution of the light, which is the result of the sun s position and the humidity in the air. The ideal module yield test, with results that can be applied to any location anywhere in the world, therefore remains not just for the technicians in the PHOTON laboratory a hard nut that has yet to be cracked. Further information Contacts page February 2013

16 Detailed results of PHOTON s 2012 yield measurements Aide Solar AD195M5-Aa / Mono : W Y/ : 1,065.0 kwh/kw (-6.91%)* 1 Y/module area: kwh/m² PR: 88.6% : 4.6 Installed in: 9/2011 Aleo Solar Aleo S_ / Multi Germany, Spain : W Manufactured: 2005 Y/ : 1,099.3 kwh/kw (-3.92%)* 1 Y/module area: kwh/m² PR: 91.5% : 9.3 Installed in: 4/2010 Alex Solar ALM-190D-24 / Mono : W Manufactured: 2009 Area: 1.27 m² TC: %/K Y/ : 1,065.8 kwh/kw (-6.84%)* 1 Y/module area: kwh/m² PR: 88.7% : 10.6 Amerisolar AS-5M-190W / Mono : W Y/ : 1,092.1 kwh/kw (-4.54%)* 1 Y/module area: kwh/m² PR: 90.9% : 11.8 Amerisolar AS-6P30-230W / Multi : W TC: %/K Y/ : 1,089.2 kwh/kw (-4.80%)* 1 Y/module area: kwh/m² PR: 90.6% : 10.1 Apollo Solar (ASEC) ASEC-235G6M / Multi Taiwan : W Manufactured: 2011 Area: 1.61 m² TC: %/K Y/ : 1,109.0 kwh/kw (-3.07%)* 1 Y/module area: kwh/m² PR: 92.3% : 10.7 * 1 deviation from test winner, * 2 no longer manufactured, * 3 Sunergy, * 5 previous model designation: CSG180S1-35/1589x807, * 6 previous model designation: CSG230M2-30/1640x992, * 7 previous model designation: ES-200-P60(230), * 8 measurement data is February

17 science & technology modules yield measurement test Detailed results of PHOTON s 2012 yield measurements Axitec AC 236P/156-60S / Multi Germany : W Manufactured: Through 2011 Area: 1.66 m² Y/ : 1,084.0 kwh/kw (-5.25%)* 1 Y/module area: kwh/m² PR: 90.2% : 4.3 Axitec AC-250M/156-60S / Mono, EU : W Manufactured: Y/ : 1,061.9 kwh/kw (-7.19%)* 1 Y/module area: kwh/m² PR: 88.4% : 4.2 Bisol BMU-215-2/221 / Multi Slovenia : W Manufactured: 2007 Y/ : 1,075.3 kwh/kw (-6.01%)* 1 Y/module area: kwh/m² PR: 89.5% : 5.7 Installed in: 2/2010 Bisol BMU-215-2/233 / Multi Slovenia : W Manufactured: 2009 Y/ : 1,086.0 kwh/kw (-5.08%)* 1 Y/module area: kwh/m² PR: 90.4% : 7.7 Bosch Solar Bosch c-si M / Mono Germany : W Manufactured: TC: %/K Y/ : 1,076.5 kwh/kw (-5.91%)* 1 Y/module area: kwh/m² PR: 89.6% : 7.0 BP Solar BP 3220 T / Multi : W Manufactured: Through 2011 Area: 1.67 m² Y/ : 1,094.5 kwh/kw (-4.34%)* 1 Y/module area: kwh/m² PR: 91.1% : 2.9 * 1 deviation from test winner, * 2 no longer manufactured, * 3 Sunergy, * 5 previous model designation: CSG180S1-35/1589x807, * 6 previous model designation: CSG230M2-30/1640x992, * 7 previous model designation: ES-200-P60(230), * 8 measurement data is 90 February 2013

18 Detailed results of PHOTON s 2012 yield measurements BP Solar BP 3280 T / Multi : W Manufactured: Through 2011 Area: 1.98 m² TC: %/K Y/ : 1,075.4 kwh/kw (-6.00%)* 1 Y/module area: kwh/m² PR: 89.5% : 5.2 Installed in: 5/2011 BP Solar BP 7185 S* 2 / Mono Spain, India : W* 3 Area: 1,25 m² TC: -0,46 %/K Y/ : kwh/kw (-14.29%)* 1 Y/module area: kwh/m² PR: 81.6% : 3.1 Installed in: 2005 BYD BYD 240P6-30 / Multi : W TC: %/K Y/ : 20.1 kwh/kw Installed in: 9/2012 Calrays CPM 250-A-96 / Mono : W Area: 1.67 m² Y/ : 1,024.7 kwh/kw (-10.43%)* 1 Y/module area: kwh/m² PR: 85.3% : 2.3 Canadian Solar CS6A-170P / Multi Y/ : 1,013.4 kwh/kw (-11.43%)* 1 : W* 3 Y/module area: kwh/m² Manufactured: 2007 (purchased) PR: 84.3% Area: 1.30 m² : 4.6 TC: %/K Installed in: 2007 CEEG Solar SST M / Mono : W Manufactured: 2005 Area: 1.62 m² Y/ : 1,085.6 kwh/kw (-5.12%)* 1 Y/module area: kwh/m² PR: 90.3% : 8.4 * 1 deviation from test winner, * 2 no longer manufactured, * 3 Sunergy, * 5 previous model designation: CSG180S1-35/1589x807, * 6 previous model designation: CSG230M2-30/1640x992, * 7 previous model designation: ES-200-P60(230), * 8 measurement data is February

19 science & technology modules yield measurement test Detailed results of PHOTON s 2012 yield measurements CEEG Solar SST P / Multi : W Manufactured: 2005 Area: 1.94 m² TC: %/K Y/ : 1,084.1 kwh/kw (-5.24%)* 1 Y/module area: kwh/m² PR: 90.2% : 11.2 CH Solar CH Solar 180 mono* 2 / Mono : W Manufactured: Through 2010 Y/ : 1,090.2 kwh/kw (-4.71%)* 1 Y/module area: kwh/m² PR: 90.7% : 8.2 Installed in: 4/2010 Chaori Solar Energy CRM240S156P-60 / Multi : W Y/ : 19.7 kwh/kw Installed in: 5/2012 Chaori Solar Energy CRM245S156M-60 / Mono : W Y/ : 20.0 kwh/kw Installed in: 5/2012 Sunergy CSUN240-60P / Multi : W Manufactured: Area: 1.62 m² Y/ : 1,069.5 kwh/kw (-6.52%)* 1 Y/module area: kwh/m² PR: 89.0% : 5.1 Sunergy CSUN250-60M / Mono : W Area: 1.62 m² Y/ : 1,085.4 kwh/kw (-5.13%)* 1 Y/module area: kwh/m² PR: 90.3% : 6.3 * 1 deviation from test winner, * 2 no longer manufactured, * 3 Sunergy, * 5 previous model designation: CSG180S1-35/1589x807, * 6 previous model designation: CSG230M2-30/1640x992, * 7 previous model designation: ES-200-P60(230), * 8 measurement data is 92 February 2013

20 Detailed results of PHOTON s 2012 yield measurements Sunergy CSUN260-60M / Mono : W Area: 1.62 m² Y/ : 1,090.1 kwh/kw (-4.72%)* 1 Y/module area: kwh/m² PR: 90.7% : 6.6 Chint Solar / Astronergy CHSM5612M (185 / Mono : W Y/ : 1,097.1 kwh/kw (-4.11%)* 1 Y/module area: kwh/m² PR: 91.3% : 10.8 Chint Solar / Astronergy CHSM6610P (230) / Multi : W TC: %/K Y/ : 1,067.7 kwh/kw (-6.68%)* 1 Y/module area: kwh/m² PR: 88.8% : 5.7 CNPV Solar CNPV-185M / Mono : W Manufactured: 2006 Y/ : 1,089.0 kwh/kw (-4.82%)* 1 Y/module area: kwh/m² PR: 90.6% : 7.6 Installed in: 3/2010 CNPV Solar CNPV-190M / Mono : W Manufactured: 2006 Y/ : 1,065.6 kwh/kw (-6.86%)* 1 Y/module area: kwh/m² PR: 88.7% : 5.6 CNPV Solar CNPV-220P / Multi : W Manufactured: 2006 Y/ : 1,090.7 kwh/kw (-4.66%)* 1 Y/module area: kwh/m² PR: 90.8% : 7.9 * 1 deviation from test winner, * 2 no longer manufactured, * 3 Sunergy, * 5 previous model designation: CSG180S1-35/1589x807, * 6 previous model designation: CSG230M2-30/1640x992, * 7 previous model designation: ES-200-P60(230), * 8 measurement data is February

21 science & technology modules yield measurement test Detailed results of PHOTON s 2012 yield measurements CNPV Solar CNPV-240M / Mono : W Manufactured: 2006 TC: %/K Y/ : 1,071.2 kwh/kw (-6.37%)* 1 Y/module area: kwh/m² PR: 89.1% : 10.3 CNPV Solar CNPV-240P / Multi : W Manufactured: 2006 Y/ : 1,099.0 kwh/kw (-3.94%)* 1 Y/module area: kwh/m² PR: 91.4% : 10.6 Conergy Conergy PowerPlus 220P / Multi Germany : W Manufactured: 2009 TC: %/K Y/ : 1,085.8 kwh/kw (-5.09%)* 1 Y/module area: kwh/m² PR: 90.3% : 7.7 Installed in: 3/2010 Conergy PowerPlus 235P / Multi Germany : W TC: %/K Y/ : 1,101.8 kwh/kw (-3.70%)* 1 Y/module area: kwh/m² PR: 91.7% : 8.9 CSG PV Tech CSG180S1-35/36* 5 / Mono : W Manufactured: 2008 Y/ : 1,106.1 kwh/kw (-3.32%)* 1 Y/module area: kwh/m² PR: 92.0% : 10.2 Installed in: 6/2010 CSG PV Tech CSG230M2-30* 6 / Multi : W Manufactured: 2008 Y/ : 1,083.3 kwh/kw (-5.31%)* 1 Y/module area: kwh/m² PR: 90.1% : 6.0 Installed in: 6/2010 * 1 deviation from test winner, * 2 no longer manufactured, * 3 Sunergy, * 5 previous model designation: CSG180S1-35/1589x807, * 6 previous model designation: CSG230M2-30/1640x992, * 7 previous model designation: ES-200-P60(230), * 8 measurement data is 94 February 2013

22 Detailed results of PHOTON s 2012 yield measurements Daqo New Energy DQ235PSCa / Multi : W TC: %/K Y/ : 1,080.5 kwh/kw (-5.56%)* 1 Y/module area: kwh/m² PR: 89.9% : 7.1 Day4 Energy Day4 48MC 185 / Multi Canada : W Manufactured: 2006 Area: 1.29 m² Y/ : 1,053.3 kwh/kw (-7.93%)* 1 Y/module area: kwh/m² PR: 87.6% : 8.0 Eging Photovoltaic Technology EGM-185 / Mono Canada : W Manufactured: 2010 TC: %/K Y/ : 1,079.9 kwh/kw (-5.61%)* 1 Y/module area: kwh/m² PR: 89.9% : 11.0 Emmvee Photovoltaics ES-230P60* 7 / Multi India : W Manufactured: Area: 1.69 m² TC: %/K Y/ : 1,039.9 kwh/kw (-9.11%)* 1 Y/module area: kwh/m² PR: 86.5% : 2.4 Installed in: 3/2010 ET Solar ET-M66250WW / Mono : W TC: %/K Y/ : 20.6 kwh/kw Installed in: 12/2012 ET Solar ET-P / Multi : W Y/ : 1,115.3 kwh/kw (-2.51%)* 1 Y/module area: kwh/m² PR: 92.8% : 10.1 * 1 deviation from test winner, * 2 no longer manufactured, * 3 Sunergy, * 5 previous model designation: CSG180S1-35/1589x807, * 6 previous model designation: CSG230M2-30/1640x992, * 7 previous model designation: ES-200-P60(230), * 8 measurement data is February

23 science & technology modules yield measurement test Detailed results of PHOTON s 2012 yield measurements Eurener PEPV230 / Multi Spain : W Area: 1.67 m² TC: %/K Y/ : 1,090.8 kwh/kw (-4.66%)* 1 Y/module area: kwh/m² PR: 90.8% : 8.9 Evergreen Solar EC-120* 2 / Ribbon USA : W* 3 Manufactured: Area: 1.03 m² TC: %/K Y/ : 1,022.7 kwh/kw (-10.61%)* 1 Y/module area: kwh/m² PR: 85.1% : 4.1 Installed in: 2006 Evergreen Solar ES-180-RL* 2 / Ribbon Germany : W* 3 Manufactured: Area: 1.50 m² Y/ : kwh/kw (-15.86%)* 1 Y/module area: kwh/m² PR: 80.1% : 2.4 Installed in: 2007 Evergreen Solar ES-A-210-fa2 / Ribbon USA : W Manufactured: 2008 Area: 1.57 m² Y/ : 1,052.0 kwh/kw (-8.05%)* 1 Y/module area: kwh/m² PR: 87.5% : 4.5 Installed in: 3/2011 Evergreen Solar ES-E-210-fc3 / Ribbon USA : W Manufactured: Y/ : 1,058.8 kwh/kw (-7.45%)* 1 Y/module area: kwh/m² PR: 88.1% : 5.7 Ferrania Solis AP / Multi Italy : W Manufactured: 2010 Area: 1.16 m² TC: %/K Y/ : 1,067.3 kwh/kw (-6.71%)* 1 Y/module area: kwh/m² PR: 88.8% : 2.1 * 1 deviation from test winner, * 2 no longer manufactured, * 3 Sunergy, * 5 previous model designation: CSG180S1-35/1589x807, * 6 previous model designation: CSG230M2-30/1640x992, * 7 previous model designation: ES-200-P60(230), * 8 measurement data is 96 February 2013