Photovoltaics Thin-Film modules

taics programme at the National Renewable Energy Laboratory (NREL) for 25 years, was quoting prices for crystalline modules ranging between 2.25 and 2.50 US$/W (approx. € 1.60 to 1.80). Amorphous silicon in difficulties

The price drop caused by worldwide overcapacity is placing considerable pressure on the manufacturers of thin-film modules made of amorphous silicon ­(a-Si). Because they are considerably less efficient, ­a-Si modules need correspondingly more surface ­area and thus more material for mounting systems and ­cabling in order to achieve the same output as a system with crystalline modules. Experts Under such as Norbert Hahn, Head of Sales at wholesaler IBC ­Solar AG, believe a price advantage of 0.80 €/W is necessary if a-Si modules are to remain competi- tive. pressure Most of the manufacturers of a-Si modules sur- veyed by us at the trade fair quoted sales prices be- tween 1.54 and 1.82 US$/W. These are not the fig- ures that appeared in the business plans of the nu- merous newcomers. Surek predicts that a-Si will achieve production costs of 1.50 US$/W at best, but not for companies that have only just started produc- tion and still have to expand their capacity in order to achieve economies of scale. “We are squeezed by crystalline silicon”, admitted Colin Chan, Manager at Formosun Solar Corporation, at the trade fair. Since June 2008, Formosun has been operating a 6 MW pro- duction line for a-Si modules in Hsinchu, Taiwan, us- ing equipment from EPV Solar Inc. in the USA. The ca- pacity is scheduled to reach 18 MW by the end of A question of price: the manu- 2009. “It is very tough for amorphous silicon”, says facturers of thin-film modules – Never have there been so many new Chan. “Every company is burning their money.” shown here is Sunfilm AG – are thin-film solar modules at Inter­ Chinese manufacturer QS Solar was more opti- facing stiff competition from mistic, having already increased capacity in Nantong their crystalline rivals. solar, but also the prices of their (Jiangsu Province) since production began in January Photos (6): Wilhelm Breuer 2008 to three lines with a total of 95 MW. In the rival crystalline competitors have Shanghai Securities News, CEO Sha Xiaolin said pro- never been so low. Things are look­ duction costs were currently 0.90 US$/W. It is planned to cut these to 0.50 US$/W within two and a ing tight for some manufacturers. half years. Whether these figures are realistic or not remains to be seen: the company is seeking capital in round 60,000 trade fair visitors! More than order to expand its capacity to 500 MW by the end of 2,000 conference delegates! A great success! 2010 and is therefore particularly interested in de- AThese are the triumphant-sounding official picting itself in a good light. ­figures for Intersolar 2009, but another figure was As to the production equipment, QS Solar were on- doing the rounds among the exhibitors in the ly prepared to say that it came from the USA, but not ­ halls at the Munich Trade Fair Centre: from a large manufacturer like Applied Materials, Inc. 1.50 €/W (approx. 2.10 US$/W). One year ago, that In an addition to fierce competitors Applied Materials would have been an attractive factory-gate price for and Oerlikon Solar as the two ‘top dogs’, the name thin-film modules. At Intersolar 2009 in late May, this ­Ulvac Inc. appears relatively frequently as an equip- figure was being quoted for modules made of crystal- ment supplier in the list of producers of new silicon line silicon cells – the dumping price offered by Chi- thin-film modules (see table on page 73). Without any nese no-name suppliers. Even established Chinese great beating of the PR drums, the Japanese equip- manufacturers such as and ment manufacturer has been able to stump up a series ­were quoting prices under 2 €/W (US$ 2.80). Shortly of sales successes, particularly in China and Taiwan. afterwards, at the Photovoltaics Summit on 1 June in Ulvac customers have frequently been heard saying San Francisco, Management Consultant Tom Surek, that equipment from Applied Materials and Oerlikon who previously worked as the head of the photovol- was too expensive.

70 Sun & Wind Energy 8/2009 Micromorph: Between hope … It is not just Oerlikon customers who are pinning their hopes on micromorph tandem modules, but al- In view of this, it is difficult to comprehend how Oer- so manufacturers relying on equipment from Applied likon will meet its stated aim of facilitating production Materials. “Customers are mercilessly asking about costs of just 0.50 €/W by 2010. Of course, the Swiss the highest efficiency”, says Torsten Brammer, Tech- equipment manufacturer is relying on its micromorph nical Director of Q-Cells’ subsidiary Sontor GmbH in technology, which combines amorphous and micro­ Bitterfeld-Wolfen (Saxony-Anhalt), which announced crystalline silicon layers to form a tandem module. At its merger with Sunfilm AG in Großröhrsdorf (Saxony) Intersolar, Oerlikon’s coating system won the Cell at the end of April. Despite the greater technical in- Award 2009 as “best technical product for manufac- put, both Sontor and Sunfilm have opted for the mi- turing thin-film solar modules”. cromorph version from the beginning. “Performance Just in time for the opening of the trade fair, the is really critical”, says Sicco Westra, Head of Business company was already publicising it in a press release: Development at Sunfilm. “The incremental perform- “New Record for Oerlikon Solar’s Micromorph Tech- ance more than justifies the incremental cost.” nology”. However, although the efficiency was spec- ified as greater than 11 % for a 1.43 m² module, this … and initial scepticism has been determined before initial light aging and only refers to the aperture area. If the specified out- Not all those in the industry would currently agree put of 151 W is reduced by 12 % to take into account with that. Because microcrystalline silicon does not the degradation, as Oerlikon itself did at the 2007 Eu- capture light as well as a-Si, a thicker layer is needed, ropean Photovoltaic Conference in Milan, and if the which correspondingly takes longer to be deposited result relates to the total module area, this leaves an from the silane and hydrogen gases. In order to com- efficiency of 9.3 %. Nevertheless, the Swiss are grad- pensate for this disadvantage, twice as many coating ually approaching their target value of 10 %. Al- systems are required than with a-Si layers to achieve though it does not use a turnkey production line, but the same throughput. Schott Solar AG, an Oerlikon a silicon chemical vapour deposition system from customer, has not yet converted from a-Si to micro- Oerlikon, Inventux Technologies AG from Berlin is morph for this reason. “The efficiency must be in aiming to produce a 140 W module by June 2010, ­double-digit figures for it to be worthwhile”, says which corresponds to an efficiency of 9.8 %. Product Manager Thomas Block.

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Sun & Wind Energy 8/2009 71 Photovoltaics Thin-Film modules

up, and will only make sense with greater efficiencies”, explains Jörg Trepte, Manager of the factory in Abu Dhabi. Just like Schott Solar and as the only customer of Applied Materials until now, Masdar therefore initially wants to produce tandem modules from two a-Si layers and, like Schott, achieve an efficiency of 7.0 %. At the PV Power Expo held in early May in Shang- hai, QS-Solar’s CEO Sha Xiaolin also declared he would not consider technology that might increase efficiency but would also considerably increase costs. His company is working on a triple cell with an a-Si layer and two different layers of amorphous silicon germanium. The Xunlight Corporation from Toledo in the US state of Ohio uses the same combination for its flexible modules made of a stainless steel sub- strate encapsulated between plastic sheets. Pro- duced on a 25 MW line, they are set to be launched on the market at the end of 2009. It is no surprise that they look very similar to the rival product from United Solar: during the first half of the 1990s, Xunlight founder Xunming Deng used to be a project manager at Energy Conversion Devices, Inc., the parent compa- ny of United Solar. New CIGS modules on the market

Amelio Solar, Inc. from Ewing in New Jersey offers a more exotic solution with the ‘PV-Duo’. The equip- ment manufacturer founded by thin-film veteran ­Zoltan Kiss (78) utilises the underneath of the front glass plate as an a-Si substrate with a rear contact made of transparent zinc oxide. This is laminated to the rear glass plate, which is utilised as a second sub- strate coated with copper-indium-gallium diselenide Invasion from the Far East: in addition to China, Taiwan now has a whole raft of new (CIGS). Both sub-modules are separately connected companies producing silicon-based thin-film modules such as Chi Mei Energy, Auria (‘4-terminal tandem’) and the different currents Solar and Formosun (top to bottom). matched with a DC converter. With an efficiency of 8 %, the CIGS module is not Although Schott Solar is not exactly known for an particularly efficient in itself, but working in tandem aggressive thin-film strategy, ambitious newcomer in the PV duo it achieves almost 11 %. Amelio is look- Masdar PV GmbH is also sceptical about the micro- ing to construct a 25 MW pilot line by the end of 2009 morph tandem technology. Masdar wants to launch and is promising production costs of only around production with a 60 MW capacity in Ichtershausen 0.75 US$/W. However, Bernhard Dimmler, Research Successful debut: Avancis, near Erfurt (Germany) at the end of 2009. A second fac- Manager at CIGS pioneer Würth Solar GmbH & Co. KG a joint venture of Shell and tory in Abu Dhabi (United Arab Emirates) is planned to in Schwäbisch Hall (Germany), does not consider the Saint-Gobain, claims an excel- go into operation at the end of 2010, which shall in- combination to be particularly cost effective accord- lent response to its new CIGS crease the overall capacity to 210 MW. The input/bene- ing to the current state of technology. He believes modules. fit ratio for micromorph modules “currently doesn’t add that with the currently realisable efficiencies, the a-Si front module is too inefficient to compensate for the proportion of light that it blocks from the CIGS mod- ule. Both Würth Solar and Sulfurcell Solartechnik ­GmbH from Berlin unveiled innovative frameless façade cassette modules at the trade fair, which can be installed on the substructure of a rainscreen clad- ding. Würth is also launching red, green, yellow, blue and white coloured modules on the market. Avancis GmbH & Co. KG enjoyed an excellent re- sponse. Since last October, the joint venture between Shell and Saint-Gobain has been producing CIGS modules in a 20 MW factory in Torgau, Saxony. “We would like to supply ten times as much”, says

72 Sun & Wind Energy 8/2009 ­Managing Director Hartmut Fischer. However, it is still ments emanating from the Shell Group in this re- not clear whether the planned expansion to achieve spect, namely that they are not looking to make any a 100 MW capacity will go ahead. Fischer neverthe- new, large-scale investments in the solar power in- less refuses to be despondent about the latest com- dustry: “Shell won’t leave us in the lurch. It stands by

New thin-film modules at Intersolar Turnkey Module Semi- Efficien- Nominal Length x width x Start of Manufacturer Country equipment name ­conductor cy*) [%] power [W] thickness [mm3] Frame delivery Manufacturer‘s website Solopower USA n/a SP1-140 CIGS 11.6 140 1,485 x 816 x 35 yes 08/2009 www..com ARTLine Würth Solar Germany n/a CIGS 11.1 80 1,200 x 600 x 70 no 10/2009 www.wuerth-solar.de WSG0059 Powermax Avancis Germany n/a CIGS 11.0 120 1,595 x 686 x 45 yes 01/2009 www.avancis.de 120 Amelio Solar USA Amelio Solar AM-165 a-Si/CIGS 10.9 165 1,519 x 1,021 x 13 yes Q1/2010 www.ameliosolar.com USA n/a AB1-72 CdTe 10.1 72.5 1,200 x 600 x 7.2 no 07/2009 www.abound.com Jenn Feng Taiwan n/a PPF505 CIGS 9.3 145 1,406 x 1,106 x 45 yes 10/2009 www.jennfeng.com USA n/a SL-001-182C CIGS 9.3 182 1,820 x 1,080 x 50 yes 01/2009 www.solyndra.com Heliosphera Greece Oerlikon HS-130 a-Si/µc-Si 9.1 130 1,300 x 1,100 x 6.4 no 09/2009 www.heliosphera.com Sharp Japan n/a NA-F128 (G5) a-Si/µc-Si 9.0 128 1,409 x 1,009 x 46 yes 08/2009 http://sharp-world.com Shurjo Energy India n/a SE145-CS CIGS 8.5 145 1,738 x 977 x 42 yes 09/2009 www.shurjo-energy.com Chint Solar China Oerlikon CHSM-120TF a-Si/µc-Si 8.4 120 1,300 x 1,100 x 7 no 07/2009 www.astronergy.com Nexpower Taiwan Ulvac NT-130AX a-Si/µc-Si 8.3 130 1,414 x 1,114 x 35.3 yes 08/2009 www.nexpw.com Auria Solar Taiwan Oerlikon M120000 a-Si/µc-Si 8.2 117.5 1,300 x 1,100 x 6.8 no 02/2009 www.auriasolar.com Beyond PV Taiwan Leybold Opt. Tandem a-Si/µc-Si 8.1 127 1,413.5 x 1,115 x 40 yes 09/2009 www.beyondpv.com ENN Solar China Applied Mat. EST-460 a-Si/µc-Si 8.0 460 2,600 x 2,200 x 7.5 no 08/2009 www.ennsolar.com Sunfilm Germany Applied Mat. Model F a-Si/µc-Si 7.9 450 2,600 x 2,200 x 8 no 04/2009 www.sunfilm.com Sulfurcell Germany SCG-HV-CC CIS 7.4 60 1,250 x 650 x 85 no 06/2009 www.sulfurcell.de Masdar PV Germany Applied Mat. a-Si/a-Si 100 a-Si double 7.0 100 1,300 x 1,100 x 8 no 12/2009 www.masdarpv.com MPE 100 Schüco/Malibu Germany Applied Mat. a-Si single 7.0 100 1,300 x 1,100 x 7.3 no 01/2009 www.schueco.com AL 01 a-Si/a-SiGe/ Xunlight USA n/a XR-36 1117 A 6.9 330 5,232 x 918 x 3.2 no 12/2009 www.xunlight.com a-SiGe Amplesun Solar China Ulvac ASF105 a-Si single 6.7 105 1,414 x 1,114 x 37.5 yes 08/2009 www.ample-sun.com Bangkok Solar Thailand Energosolar BS-52 a-Si double 6.6 52 1,245 x 635 x 7 no 06/2009 www.bangkoksolar.com South Alti-Solar Ulvac ALTS-S1007 a-Si single 6.3 100 1,414 x 1,114 x 37.5 yes 07/2009 www.alti-s.com Korea Chi Mei Energy Taiwan Ulvac CSSS-100 a-Si single 6.3 100 1,414 x 1,114 x 35 yes 03/2009 www.chimeienergy.com General Solar Power China Ulvac GA-100-GB a-Si single 6.3 100 1,414 x 1,114 x 37.5 yes Q1/2010 www.solargsp.com GS-Solar China n/a GS-50S a-Si/a-SiGe 6.3 50 1,245 x 635 x 7.5 no 09/2009 www.gs-solar.com JS-100AX- Jiasheng Solar China Ulvac a-Si single 6.3 100 1,414 x 1,114 x 35.3 yes 01/2009 www.jssolar.com 1_4A Sunner Solar Taiwan Ulvac SA-100 a-Si single 6.3 100 1,414 x 1,114 x 35 yes 10/2009 www.sunnersolar.com Moser Baer PV India Applied Mat. MBTF 85 a-Si single 6.2 88 1,300 x 1,100 x 7.5 no n/a www.moserbaerpv.com T-Solar Global Spain Applied Mat. TS350 a-Si single 6.1 351 2,600 x 2,200 x 7.5 no 12/2008 www.tsolar.eu HHV Solar India HHV HST12060 a-Si single 6.0 60 1,000 x 1,000 x 40 yes 12/2009 www.hhvsolar.com QS Solar China from USA QS90SGU a-Si double 5.9 90.3 1,400 x 1,100 x 22 no 07/2009 www.qssolar.com Suntech Power China Applied Mat. STP080Ts-AA a-Si single 5.6 80 1,300 x 1,100 x 7.5 no 10/2009 www.suntech-power.com Formosun Solar Taiwan EPV Solar PV44 a-Si double 5.6 44 1,245 x 635 x 24 no Q3/2008 www.formosun.com Polar PV China n/a TFSM-T-1 a-Si double 5.6 44 1,245 x 635 x 7 no 05/2008 www.polar-pv.com CN Solar China from China Tandem a-Si double 5.2 41 1,245 x 635 x 7 no 10/2009 www.zjcnsolar.com Taiwan/ Han Fung Solar Amelio Solar HF-40 a-Si double 5.1 40 1,245 x 635 x 25 no 09/2009 www.hanfungsolar.com China Switzer- VHF-Technologies n/a FLX-TO200 a-Si single 3.0 200 3,700 x 1,800 x 2.4 no**) 01/2009 www.flexcell.com land *) related to the total area; highest power module of the manufacturer, Flood of products: Compared to our overview last year, **) roof membrane made of thermoplastic elastomer polyolefins (TPO) with edge trim CIGS: copper indium gallium diselenide CIS: copper indium disulfide CdTe: the number of new thin-film modules at Intersolar has a-Si: amorphous silicon a-SiGe: amorphous silicon-germanium µc-Si: microcrystalline silicon more then doubled. Source: Manufacturers‘ information

Sun & Wind Energy 8/2009 73 Photovoltaics Thin-Film modules

its investment”, but he points out that dipping (presumably in a nanoparticle ink) and heat- the decision will also need to be based ing (to crystallise the CIGS layer). In addition to Tai- on the general economic situation. wan universities, the Dutch equipment manufactur- Avancis has further developed the er Smit Ovens B.V., which is a specialist for thermal technology of its predecessor compa- processes, is also involved in the development. Ac- nies Shell Solar, Siemens ­Solar and Arco cording to the data sheet, the 145 W module has an Solar. These innovations relate in partic- efficiency of 9.3 %, the smaller 75 W version 9.6 %. ular to the vapour deposition of selene It was actually another company that wanted to on the copper-­indium-gallium layer with hit it big in 2009 with CIGS modules based on nano­ subsequent rapid thermal processing in- particles: Nanosolar, Inc. in San José. Although the stead of treating it with toxic hydrogen start-up company already announced the start of selenide, and the use of a silicon nitride commercial production back in December 2007, barrier layer to prevent sodium diffusing there has been no continuous fabrication since from the glass substrate, whereby con- then. That has been confirmed by several experts trolled sodium doping is utilised (SUN & who have seen the factory from the inside. WIND ENERGY 1/2007, p. 92). The ap- proximately 1.6 x 0.7 m² modules enable Winnowing process begins Avancis to achieve efficiencies approach- ing 11.0 %. On the other hand, Abound Solar, Inc. (previously AVA Solar) from Longmont in the US state of Colo- Alternative production rado has achieved the breakthrough. After 15 Sceptic: Masdar PV believes methods years of research and development at Colorado that micromorph technology State University, the company launched a 65 MW is only profitable with greater The CIGS modules from the Californian start-up com- factory for manufacturing modules from cadmium efficiencies and is initially pro- pany Solopower, Inc. were also premiered at Inter­ telluride (CdTe) in April, whose capacity is planned ducing tandem modules with solar. GET GmbH in Munich exclusively sells these in to be expanded to 200 MW by the beginning of two amorphous silicon layers. Europe. Solopower produces CIGS cells by electroplat- 2010. The modules, which have a maximum effi- ing the semiconductor elements onto a stainless steel ciency of 10.1 %, were exhibited at Intersolar by foil substrate in a roll-to-roll process and then con- their German sales partners Juwi Solar and nects them in a similar manner to standard cells made ­Wirsol. from silicon wafers to form a module (SUN & WIND Abound Solar is looking to achieve production ­ENERGY 6/2008, p. 132). In terms of shading, having costs less than 1 US$/W. This means that the com- 20 bypass diodes gives the modules an advantage pany is well equipped for a fierce price war. How­ over monolithically integrated thin-film modules ever, a gradual winnowing process will undoubted- whose cells are created with laser-etched trenches. ly begin among the numerous manufacturers of Such modules are mostly equipped with just one by- ­silicon-based thin-film modules. The Japanese top pass diode. According to GET Managing Director Ismail of the class Sharp probably holds the best cards Avan, 90 % of the Solopower modules from the recent- here: its micromorph modules have a peak efficien- ly launched 10 MW line in San José achieve outputs be- cy of 9.0 %, not just on paper but in production; its tween 100 and 120 W. That corresponds to an efficien- Katsuragi plant has been running at a 160 MW ca- cy of 8.3 to 9.9 %. Small volumes with 140 W even pacity since October 2008; from spring 2010 on, it achieve 11.6 %. will gain synergy effects with the manufacture of This is a very good value for a galvanic process. LCD screens at its new gigawatt plant in Sakai; a By way of comparison: Inc. in strong corporate group is backing it up; it is a Tucson (Arizona) produces CIGS cells on stainless ­recognised brand name, and it has a well-developed­ steel foil by coevaporating the semiconductor ele- dealer network. ments. Indian module manufacturer Shurjo Energy Observers disagree about the future prospects Pvt. Ltd then processes these cells to form modules of CIGS module manufacturers. Tom Surek has enor- with a maximum efficiency of 8.5 %. The best mod- mous doubts: “I just don’t see any of them having Further information: ules from Würth Solar, which work with the same the right cost structure”, he said in San Francisco. Applied Materials: www.amat.com process on glass, achieve 90 W (even if the data Others point out that CIGS has not yet developed as EPV Solar: www.epvsolar.com : www.firstsolar.com sheets specify a maximum of 80 W) and thus an effi- much in cost terms as CdTe, but has the ability to Global Solar Energy: ciency of 12.5 %. catch up with larger capacities. The fact that they www.globalsolar.com Jenn Feng Industrial Co., Ltd from Taiwan has de- might be right is actually proved by CdTe pioneer IBC Solar: www.ibc-solar.de Inventux Technologies: veloped a new technology for manufacturing mono- First Solar: last October, the market leader hired www.inventux.com lithically integrated CIGS modules. In order to form proven CIGS specialist Markus Beck, who used to be Nanosolar: www.nanosolar.com the CIGS layer on the glass substrate, the company Chief Scientist at Solyndra and Global Solar. Maybe, Oerlikon Solar: www.oerlikon.com/solar Schott Solar: www.schottsolar.com uses a non-vacuum process with nanoparticle precur- First Solar is making provisions should the debate Smit Ovens: www.smitovens.nl sors. Although Jenn Feng does not want to reveal any about toxic cadmium rebound in its face or there is Sontor: www.sontor.com details before its 30 MW line goes online in Taoyuan a shortage of tellurium. In any case, CIGS evidently Ulvac: www.ulvac.co.jp/eng United Solar: www.uni-solar.com in October, one thing is clear: the process combines has a future in the eyes of First Solar. Yingli: www.yinglisolar.com sputtering (probably for the front and rear contacts), Johannes Bernreuter

74 Sun & Wind Energy 8/2009