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News for the Solar Manufacturing Industry
Volume 3 Number 4 April 2010
New survey outlines challenges and opportunities for CPV Does the solar industry need high purity performance chemicals? Improvements at the absorber layer needed to keep thin-film silicon PV alive in the marketplace
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Contents
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Contents 2
Volume 3, Number 4 April 2010
Hang on tight! Alan Rae
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Technology Focus
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New survey outlines challenges and opportunities for CPV Jim Handy, Objective Analysis; Terry Peterson, solar power consultant; Obadiah Bartholomy, SMUD; Travis Coleman, EPRI
18 Structural adhesives: a bonding alternative for solar panels Ian Quarmby and Nicole Wood, LORD Corporation and Kimberly Kayler, Constructive Communication 22 Does the solar industry need high purity performance chemicals? Scott Schumacher, Peak Sun Silicon
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Special Features
12 14 19 20 21 27 28 28 29
Improvements at the absorber layer needed to keep thin-film silicon PV alive in the marketplace Looking into the US Department of Energy’s “Solar America Cities” program Lux predicts challenging times ahead in solar PV Innovating with bio-based backsheet materials VDMA Photovoltaic Equipment: Another significant decrease in turnover Interview—Jean-Noel Poirier, Global Solar Energy Flextronics ramps up solar capabilities Solar growth in Asia/Pacific Giving your metallization process the “OK”
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Regular Features
3 Industry News 30 New Products 32 International Diary Visit the website for more news & content: www.globalsolartechnology.com. A flexible, robot-based automation system aids in the production of solar modules. (Source: KUKA Systems)
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Global Solar Technology – April 2010 – 1
Editorial
Editorial Offices
Europe Global Solar Technology Trafalgar Publications Ltd 8 Talbot Hill Road Bournemouth Dorset BH9 2JT, United Kingdom Tel: +44 (1202) 388997 news@globalsolartechnology.com www.globalsolartechnology.com United States Global Solar Technology PO Box 7579 Naples, FL 34102, USA Tel: (239) 567-9736 news@globalsolartechnology.com China Global Solar Technology Electronics Second Research Institute No.159, Hepin South Road Taiyuan City, PO Box 115, Shanxi, Province 030024, China Tel: +86 (351) 652 3813 Editor-in-Chief—Trevor Galbraith Mobile: +1 239 567 9736 editor@globalsolartechnology.com Managing Editor—Heather Lackey hglackey@globalsolartechnology.com Technical Editor—Dr. Alan Rae arae@globalsolartechnology.com Editor—Debasish Choudhury dchoudhury@globalsolartechnology.com Circulation and Subscriptions Tel: +1 (239) 567 9736 subscriptions@globalsolartechnology.com
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Print & Digital - Europe Adela Ploner 08131/3669920 aploner@globalsolartechnology.com (UK & Ireland): Donal McDonald Tel: +353 86 2485842 dmcdonald@globalsolartechnology.com
Print - North America Ron Friedman Tel:+1 (860) 523-1105 rfriedman@globalsolartechnology.com Digital - North America Sandy Daneau Tel: +1 (603)-686-3920 sdaneau@globalsolartechnology.com Asia/Pacific Print - Debasish Choudhury Tel: +91 120 6453260 dchoudhury@globalsolartechnology.com 2 – Global Solar Technology – April 2010
Dr. Alan Rae
Technical Editor, Global Solar Technology
Hang on tight! Summer is the season for roller coasters…the sickening feeling in the pit of your stomach as you see the upcoming drop, the many twists and turns and the exhilaration as you build up momentum and zoom upwards again…does it remind you of the solar PV business? iSuppli’s latest forecast—dated 20 April—is very positive. The combination of German demand to beat Feed-in Tariff reductions and the lowering of prices should drive installations in 2010 to 13.6 GW, up 93.6% from 2009. Further robust growth will lead to a module and inverter supply crunch. Lux research also foresees strong growth, but preceded by a shakeout. Read what they have to say about the future trends on page XX. This month we review some of the new entrants to the business, including the very capable electronic contract manufacturers such as Flextronics. They have done a terrific job ironing out supply chains for computers, handheld devices, game consoles and a whole range of communications products. Let’s see what they can do for solar PV. Jim Handy from Objective Analysis has a revealing review of the CPV business. He also heads up the photovoltaics chapter team on the iNEMI roadmap, and later in the year we’ll be talking about the supply chain in general through the iNEMI roadmap process. We’re reviewing a new process control tool from ECD, new materials from BioSolar and meeting an important new team member at Global Soar Energy.
Finally, and most important of all, let’s not forget about the customer. As I’ve mentioned in a previous editorial, growth is dependent on customers—and these customers are not finding it easy to transition to the solar economy. In many areas, local government, utilities and contractors just aren’t clued in to what’s needed. Surveys, permits, grants, financing, tax implications, utility connections, building codes…the list is long. The US Department of Energy’s Solar America Cities program is a practical way for cities to learn from leaders in the field (such as San Francisco) and apply those lessons learned with practical support from the National Renewable Energy Laboratory. It’s something that module and system makers should know about and is a successful system that could be applied widely. So enjoy the roller coaster ride and hang on tight! —Alan Rae, PhD
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Title Industry news
Industry news DuPont opens photovoltaic application facility in Geneva
To address the needs of the fast-growing photovoltaic market, DuPont opened the Meyrin Photovoltaic Application Laboratory at its European Technical Center, adding new capabilities to this leading R&D hub by developing nextgeneration products. Over 50 representatives from the photovoltaic industry joined government leaders and DuPont Chair and CEO Ellen Kullman and Ian Hudson, president— DuPont Europe, Middle East and Africa, for the facility’s opening. “Addressing energy needs is a global concern. The generation and storage of renewable energy will be the fastest growing sector in the energy market for the next 20 years,” said Kullman. “We can apply the power of our market-driven science to offer products and technologies that can transform the sun’s potential into clean energy, contributing to decreasing dependence on fossil fuels.” The Meyrin Photovoltaic Application Lab will operate as an open center, enabling technological exchanges and research collaborations between DuPont and customers, industrial partners, institutes and academia. The lab is designed to advance state-of-the-art solar module design, accelerate time to market in photovoltaic innovation and deliver cost-effective, high-performance solutions for the photovoltaic industry. photovoltaics. dupont.com Solarfun’s ECLIPSE modules feature reduced LID Solarfun Power Holdings Co., Ltd. introduced a new line of PV cells and modules under the name “ECLIPSE” that offer reduced light-induced degradation
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(LID). The largest percentage of degradation of PV modules occurs during the first day of sun exposure. ECLIPSE reduces the impurity concentration in cells, therefore reducing the relative LID to about 1% from 2% to 3%, or less than 2W compared to about 4W to 5W for a 180W module equipped with standard cells. This results in an increase in electricity generation of about 1% to 2% more power over a one-, five-, 10-, and 25- year period when compared with standard modules. Peter Xie, President of Solarfun, commented, “We have devoted considerable resources and management attention to develop and produce differentiated products. We are proud to introduce this innovation in our new ‘ECLIPSE’ line with reduced LID.” www. solarfun-power.com UC Merced professor gets $568K solar energy study grant One of UC Merced’s School of Engineering’s assistant professors, Alberto Cerpa, received a $568,202 grant from the National Science Foundation. The grant will be used to develop a system that will measure and track the amount of sunlight that reaches ground level. Findings will be applied to photovoltaic panels and solar concentrators used in solar energy systems that collect light and heat to turn into electricity. The three-year grant, funded under the federal American Recovery and Reinvestment Act of 2009, is for the project “MRI: Development of ASSIST: Affordable System for Solar Irradiance Sensing and Tracking.” Cerpa, along with associate professor Carlos Coimbra and assistant professor Qinghua Guo, is developing a system that will help make it easier for energy producers to determine the most optimal opportunities to use solar. Evonik, 10X Technology form photovoltaic manufacturing alliance Evonik Cyro LLC, a manufacturer of acrylic sheet and molding compounds and bulk and performance monomers, and 10X Technology LLC, an emerging company that develops micro- and nano-structured polymer substrates, have formed an alliance
to commercialize novel materials for the photovoltaic market. The companies will initially focus on co-developing lenses that improve the performance of a range of energy-related products from solar energy systems to interior lighting. Among the products that the companies will co-develop are solar concentrator lenses, which improve the efficiency of solar cell systems by focusing sunlight on a selected area of semiconductor material. Concentrated photovoltaics (CPV) is a rapidly emerging field within the solar industry and is expected to increase conversion effectiveness and the relative energy output for a given area of space. “Plastic or glass can function as the exterior surface of a solar cell system, but just imagine if that same surface could also concentrate sunlight,” said Bob Pricone, President of 10X Technology. “In the same dimensional space, we could increase energy production by several multiples.” www.evonik.com/north-america, www.10xtechnology.com Trina Solar boosts cell conversion efficiency Trina Solar Limited (TSL) achieved a breakthrough in its development of monocrystalline cell technology. As part of the company’s ongoing research and development strategy, Trina Solar has developed a square monocrystalline cell with enhanced power output using its proprietary improved cell manufacturing process. Using specially designed metallization and passivation techniques, the advanced cell structure is expected to significantly boost cell conversion efficiency, achieving up to 18.8% efficiency in test laboratory production. In addition, this technology is expected to improve module output due to increased light absorbing surface area of the square shaped cell. Trina Solar aims to develop solar cell conversion efficiences of more than 20% over the coming two years. www.trinasolar. com TestLab Solar Thermal Systems at Fraunhofer ISE expands testing capabilities With increased capacity and more flexible
Global Solar Technology – April 2010 – 3
Industry News
measurement equipment, the TestLab Solar Thermal Systems at Fraunhofer ISE steps up to the growing international demand for the investigation of solar thermal systems. Formerly called the Testing Centre for Thermal Solar Systems, the Fraunhofer ISE establishment has been newly renamed TestLab Solar Thermal Systems. This facility is authorized by the German certification authority DIN CERTCO, the Portuguese certification authority CERTIF and the American Solar Rating and Certificate Corporation SRCC. With the accumulated expertise of more than ten years, the specialized engineers perform tests on solar collectors as well as on complete systems. In addition, they assist industry customers worldwide in the development of solar thermal system components. www.ise.fraunhofer.de Prism Solar and PPG Industries partner to test performance of antireflective glass in solar modules Prism Solar Technologies and PPG Industries have partnered on a project to test the performance of different types of glass in both standard and holographic photovoltaic (PV) modules at various incident and direct angles. The test will compare PPG’s Solarphire® AR hightransmissive glass to patterned glass to determine the increase in energy yield. Prism Solar will be characterizing the performance of PPG’s anti-reflective glass and patterned glass to determine the increased energy yield in relation to angular performance. By measuring energy yield from a series of modules characterized to be equivalent in terms of peak watt rating, it will be possible to determine the added value of anti-reflective properties for mono-facial modules as well as bifacial Holographic Planar Concentrator modules. Test arrays with tilt angles from 0° to 90° will be explored to provide data on a full range of possible array tilt angles. Increasing the energy yield of PV modules offers numerous advantages on the system level by reducing the number of peak watts needed to produce a given number of kWhs. The more kWhs generated per peak watt means a lower levelized-cost-of-energy (LCOE, or $/Wh) through reduced capital expenditure and a reduction in operation and maintenance costs for the system. www.prismsolar.com, www.ppg.com SolarWorld finishes No. 1—again— in energy-productivity test For the second year in a row, SolarWorld’s solar power technology has demonstrated
4 – Global Solar Technology – April 2010
the highest electricity production performance in the world’s only independent, industry-wide test, staged annually by Photon magazine. SolarWorld’s modules have generated more electricity than all competitive products for each watt of capacity installed in Photon tests in both 2009 and 2008. In comparison with other modules, the SolarWorld products produced up to 12 percent more power in 2009. www. solarworld-usa.com KYOCERA achieves World record conversion efficiency for multicrystalline solar modules Kyocera Corporation achieved a new world record of 16.6% module efficiency (aperture-area efficiency of 17.3%) for multicrystalline silicon solar modules using 54 cells in the development stage. To achieve this record, Kyocera further improved its proprietary “Back Contact” technology and module design to optimize the performance of each cell, thus increasing overall energy conversion efficiency. Kyocera, which possesses a fully-integrated production system— from processing raw silicon material to manufacturing cells and modules— continually advances its technology to yield higher energy efficiency from its solar cells and modules. Kyocera’s Back Contact technology moves electrode wiring that is typically arranged on the surface of the cell to the back side, thus increasing the light capturing surface area to maximize energy conversion efficiency. Kyocera has achieved an energy conversion efficiency of 18.5% for individual solar cells in the development stage. global.kyocera.com/prdct/ solar Fraunhofer ISE and VDE expand cooperation In cooperation with the Solar Energy Research Institute of Singapore SERIS, the VDE Institute and the Fraunhofer Institute for Solar Energy Systems ISE have opened up the first testing and certification center for photovoltaic modules in South East Asia. “Together with our partners, we are now able to offer the photovoltaic industry in South East Asia a Center in their region where modules can be tested and accredited according to the established international standards,” says Dr. HansMartin Henning, coordinator of the joint venture from the Fraunhofer side and deputy director of Fraunhofer ISE. In the cooperation, the new Joint
Venture company, VDE-ISE Pte. Ltd., founded by VDE and Fraunhofer ISE, is under the leadership of Henry Paetz. The company is responsible for the customer service, certification and safety tests according to IEC 61730, while the Solar Energy Research Institute of Singapore SERIS, under the leadership of Prof. Joachim Luther, carries out the various performance tests. Fraunhofer ISE has many years of experience in the calibration of solar modules, and for more than three years now, Fraunhofer ISE has been operating its own test center for photovoltaic modules, where various tests based on accepted international standards are offered to customers for product testing and certification. Through the partnership with VDE, certifications according to IEC 61215 for PV modules based on crystalline silicon cells and according to IEC 61646 for modules based on thin film solar cells are offered. The VDE – the Association for Electrical, Electronic and Information Technologies – is an independent, nationally and internationally accredited institution. Under the leadership of Wilfried Jäger, Managing Director, the VDE is responsible for testing and certifying the safety and performance of electronic devices, components and systems for the consumer and the general public using the highest standards of quality. The Solar Energy Research Institute of Singapore SERIS, whose director Prof. Joachim Luther is the former Director of Fraunhofer ISE, exists since April 2008. It carries out research on the industrial level in the areas of solar cells, module development and energy efficient building. www.ise.fraunhofer.de RASIRC granted patent for specialty seal in ultrapure environment The US Patent and Trademark Office has granted RASIRC Patent #7,625,015B2 for a novel adhesive and weld-free assembly technique for working with hollow fibers and ultrapure materials. The patented process allows for the simultaneous sealing of multiple tubes within a single outer shell when an external radial compressive force is applied. The seal is used in both RainMaker® Humidification Systems (RHS) and RASIRC Steamers. “It is quite difficult to assemble hollow fibers without glues or thermal bonds. Our unique method to assemble dissimilar materials allows us to create an ultrapure
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Industry News
seal that works in high temperature and steam environments,” said RASIRC founder and president Jeffrey Spiegelman. www.rasirc.com Heliodyne announces sublicense agreement with Alanod-Solar Heliodyne Corporation entered into a sublicense agreement with Alanod-Solar, Inc, under the terms of which AlanodSolar will become the sublicensee of Heliodyne’s rights to use a patent owned by Sandia Corporation for the laser welding of metal fins to metal tubes. The financial terms of the Agreement are confidential. Heliodyne uses the technology in the manufacturing of collectors for solar hot water systems. Alanod-Solar, Inc. manufactures components for solar collectors, and is also a parts supplier to other solar collector manufacturers. Heliodyne is currently the sole and exclusive licensee of Sandia’s laser welding patent, U.S. Patent No. 6,300,591. Under the terms of its license with Sandia, Heliodyne may enter into sublicenses with other companies in the industry. www. solarcap.dk, www.heliodyne.com Sopogy wins Small Business Success Award for innovation Sopogy, Inc., the world’s first microconcentrated solar power provider, garnered an award in the Innovation category presented at the Hawaii Business 2010 SmallBiz Success Awards Event at the Hawaii Prince Hotel. Hawaii Business magazine annually honors outstanding Hawaii-based small businesses for rapid sales growth, a unique product, notable longevity, overcoming an unusual challenge or executing a dramatic turnaround. Nearly 100 nominations were evaluated by a panel of ten judges consisting of C-level executives from Hawaii small businesses and organizations, as well as Hawaii Business magazine senior writers. Sopogy’s award-winning MicroCSP™ technologies efficiently and cost-effectively generate electricity, steam, solar air conditioning and other thermal energy forms, helping customers achieve their renewable energy goals and faster paybacks for their investment. www.sopogy.com Coherent announces > $20M solar cell tool orders in fiscal Q1 2010 Coherent Inc. has secured multiple orders totaling in excess of $20M from crystalline silicon solar cell manufacturers for laser-
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based process tools—just three months after releasing the Coherent Equinox™ and Aethon™ products at the EU PVSEC exhibition in Hamburg. Comprising some of the largest orders for laser-based tooling to date within the solar industry, deliveries are scheduled for completion in the first half of calendar 2010. These tools are the latest additions to our complete portfolio of lasers and laserbased systems for photovoltaic production processes. www.Coherent.com CNPV signs long-term strategic partnership with Delta Sud CNPV Solar Power SA has entered into a long-term strategic partnership sales agreement with Delta Sud, a wellknown French project development and distribution company. Under the terms of this strategic agreement, CNPV will supply Delta Sud with a total of 20MWp of PV modules from 2010 to 2012, which includes 2.50MWp of scheduled delivery during 2010.The remaining 7.50MWp and 10MWp are scheduled for delivery in 2011 and 2012 respectively. www.cnpv-power.com, www.energie-rhone.fr aleo solar AG expands market leadership in Mexico aleo solar AG has signed a supply contract with the Mexican installation company Grupo Desmex S.A., further expanding its leading position in the Mexican photovoltaic market. The frame contract covers solar modules with a rated output of 5,000 KW, which are to be supplied by the end of the year. www. aleo-solar.de
motion. The production plant will create approximately 150 direct jobs in Ontario. The manufactured equipment will produce clean power equalling the consumption of roughly 19,000 households. The new plant will join the other Siliken plants that are currently productive in Valencia (Spain) and San Diego (California, USA). www.siliken.com Largest NW utility-scale solar project will use medium voltage inverter platform from PV Powered PV Powered, Inc.’s PowerVault DC-to-medium voltage turnkey inverter platform has been selected for use in the Northwest’s largest utility-scale project to date. The first project will begin installation in April with additional 5MW projects to follow in 2010. The project is being developed in Lake County, Oregon, near Christmas Valley, by the Obsidian Finance Group of Portland, Ore. www. pvpowered.com Hanwha commissions Spire’s 30MW solar cell manufacturing line Spire Corporation’s 30M W per year turnkey solar cell line has been accepted by Hanwha Chemical Corporation Ltd. of South Korea (Hanwha). The line exceeded both its efficiency and throughput specifications, producing 15.8% efficient multi-crystalline silicon solar cells at the rate of more than 34M W per year. “This is Hanwha’s debut to the solar cell market and this line makes them very competitive,” said Roger G. Little, chairman and CEO of Spire Corporation. www.SpireCorp.com
International Siliken to build a PV module production plant in Ontario, Canada
Trina Solar announces sales agreement with AE Photonics Trina Solar Limited entered into an agreement with AE Photonics (“AE Photonics GmbH”) of Germany for 40 MW of PV modules to be delivered during 2010. Under the terms of the agreement a total of 20 MW will be shipped during the first half of 2010 with agreed prices for the first quarter. Initial shipments commenced in January 2010. www.trinasolar.com, www. ae-photonics.com
The Siliken Group of renewable energy companies will open a plant manufacturing photovoltaic modules in Ontario, Canada, with an initial production capacity of 50 MW. It could start operations as early as the last quarter of 2010. Siliken is completing the choice of location and the necessary legal paperwork in order to set this plant in
IPVEA supports the petition of the German solar industry The International Photovoltaic Equipment Association (IPVEA) supports the petition of German solar companies and the Federal Association of the German Solar Industry to scale back the level of the Continued on page 24
Global Solar Technology – April 2010 – 5
New survey outlines challenges and opportunities for CPV
New survey outlines challenges and opportunities for CPV Jim Handy, Objective Analysis; Terry Peterson, solar power consultant; Obadiah Bartholomy, SMUD; Travis Coleman, EPRI
Concentrating photovoltaics, or CPV, has recently been attracting significant attention as a way to reduce the cost of solar energy. Numerous startups, as well as companies that have been around a while, are vying to use CPV techniques to outperform more conventional forms of photovoltaic power generation. This article, based on research conducted by the Electric Power Research Institute (EPRI) for the Sacramento Municipal Utility District (SMUD), explores this approach to solar power generation, explains how it works and where it performs the best, and gives information on the companies who supply or aspire to supply CPV systems.
Keywords: CPV, LCPV, HCPV, DNI, Refractive, Reflective
6 – Global Solar Technology – April 2010
Why CPV? CPV is just starting to come of age. Much of this technology’s progress was prompted by the 2006-2008 polysilicon shortage that focused significant attention on ways to reduce the amount of photovoltaic material needed to harvest solar energy. The reason is simple: photovoltaic cells are expensive. If the amount of sun that hits the cell can be increased, then the amount of expensive cell material used to generate a watt of electricity can be reduced. Although the price of polysilicon has recently tumbled, it is still much higher than the prices of materials that can be used to focus more light onto a solar cell. Most CPV systems are manufactured using materials that are abundantly available, such as aluminum, steel, glass, and acrylic plastic. Typical CPV systems shy away from using high-cost and rare materials (other than the photocells themselves), and CPV companies devote significant efforts toward developing systems that can be manufactured using standard high-volume production techniques in widespread use today. Today there is a lot of promise in CPV, but the technology is still not the most cost-competitive solution even in regions with significant sunlight. This is largely due to the fact that the technology is new and has not been able to take advantage of economies of scale that proponents expect to make it competitive. In order for CPV to reach terawatt-scale usage system costs will need to reach $1-2/watt, a range comparable to today’s costs for competing technologies. Today, based on the surveys conducted by EPRI for this report, CPV systems cost around $5/watt or more to install. There are two fundamental approaches to increasing the amount of sunlight that hits a solar cell: reflection and refraction. The number of ways these two
Figure 1. Cassegrain reflector optic system. (Courtesy of SolFocus.)
approaches are employed is as varied as the imaginations of the many companies who are pioneering CPV systems. Typical reflective CPV systems employ anything from flat mirrors to arrays of parabolic dishes to concentrate the sun onto the photovoltaic material, depending on the level of concentration the system is to use. Higher concentrations warrant more elaborate reflection techniques. A two-sun concentrator can be produced using nothing but a standard solar flat panel teamed with flat mirrors on either side. A 500-sun concentrator may use a more elaborate Cassegrain optic system in which a dish mirror directs light onto a secondary reflector that focuses the sun’s rays into a kaleidoscopic rod that helps compensate for tracking errors (Figure 1). This “non-imaging optical system” takes advantage of the fact that the light that hits the focal point of the optics doesn’t need to actually look like the sun, as long as the
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New survey outlines challenges and opportunities for CPV
Figure 2. Refractive HCPV system. (Courtesy of Amonix, Inc.)
vast majority of the captured light actually arrives at the face of the photocell. Refractive CPV systems tend to start at 300 suns of concentration and rise to 2,000 suns. Although most of these systems employ Fresnel lenses (a lens that can be made far flatter than a standard spherical lens), some models use domed or other shape lenses. One advantage to the use of Fresnel lenses is that they are typically manufactured with one flat side and one textured side, and the flat side is very easy to clean. Since the system will be outdoors and exposed to a good bit of dirt, this is an important advantage. A difference of Fresnel systems when compared to a Cassegrain system is that the Fresnel approach requires more distance between the lens and the focal point (leading to a larger structure) due to the fact that these systems do not fold the light path. See the schematic in Figure 2. High concentration vs. low concentration Although the terms “high concentration” and “low concentration” are widely bandied about, there is no real standard defining where one ends and the other begins. Just to confuse matters, some use the term “medium concentration” as a category between the two. For this article, we will define low concentration photovoltaics or LCPV to be anything at or below 100 suns and high concentration photovoltaics (HCPV) as anything above 100 suns. Of the 50 systems for which EPRI collected concentration figures, none
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fall into the gap between 70 and 120 suns, which makes this a logical breakpoint. Once the sun is concentrated a new challenge presents itself – it is no longer sufficient to simply mount the panel in a fixed position to accept the sun’s rays from whichever angle they approach. Focusing the sun’s rays necessitates one or two axis tracking of the sun by the array. The higher the concentration, the narrower angle over which the system generates optimal output, known as the acceptance angle. LCPV systems can get by with singleaxis tracking, since most LCPV systems only focus light in a single axis, a technique known as line focus. Tracking is performed along this single axis, and the other axis is fixed. HCPV systems focus the light in a single spot or point focus necessitating the use of 2-axis tracking, a factor that adds cost and complexity to the system, but allows concentrations to be increased by an order of magnitude. The added cost of a tracker offsets some of the savings of CPV, and creates additional maintenance requirements. It is widely held that HCPV systems are more suited to utility-scale installations rather than roof-mounted systems because of the difficulties of mounting trackers on existing buildings. Most systems attempt to minimize the number of trackers in a deployment by placing a very large array on a single pedestal. The weight and stresses generated by such a system, much of which is due to wind loading, require it to be mounted directly on the ground. Some companies are pursuing an alternative in which a number of small panels are mounted onto small trackers
that do not suffer from the high weight and stress. While there is a definite benefit in avoiding wind loading, a potential disadvantage to this approach might be increased maintenance required by the system’s larger number of mechanical components. How DNI impacts CPV CPV is not well suited to regions where there is significant cloudiness or atmospheric turbidity. In such areas, flat-plate PV can capture a larger fraction of the annual solar energy and tend to provide more cost-effective solar power. CPV is better suited to regions with cloudless skies and significant sunshine such as those found in the southwestern U.S., southern Europe, the great deserts, and the sunniest parts of China, India, and Australia. These areas have high direct normal insolation (DNI) - a measure of the amount of solar radiation hitting a surface perpendicular to the sun’s rays which hasn’t been scattered or reflected by atmospheric conditions. DNI is usually measured in kilowatt-hours per square meter per day, with levels of 6 and higher generally called “high” DNI. The map in Figure 3, compiled by the U.S. Energy Department’s National Renewable Energy Lab (NREL), uses color to show how DNI varies across the United States. The red areas on the map are more likely to be the preferred locations for CPV plants. Areas with lower DNI can still have sufficient sunlight to economically produce solar power, but in these regions flat plate collectors are often the more economical
Figure 3. Map of DNI in the United States.
Global Solar Technology – April 2010 – 7
New survey outlines challenges and opportunities for CPV
Figure 4. Map of solar resource for a collector at latitude tilt.
Figure 5. Ratio of DNI to global insolation versus global insolation.
way to generate electricity. In such areas the total solar resource or global insolation may be higher than the DNI. The map of Figure 4 illustrates the solar resource of the United States for a south facing flat plate tilted to compensate for the region’s latitude. As with the DNI map of Figure 3 the solar resource is measured in kilowatthours per square meter per day. One way to look at the difference between these two maps is with a chart like Figure 5 from the EPRI report. This chart illustrates the differences between
8 – Global Solar Technology – April 2010
the data in Figure 3 and that in Figure 4 for several different cities in the US. In effect it compares DNI to total sunlight and finds that relative amount of sunlight available for CPV versus flat-plate PV decreases by about 30% from the sunniest to the least sunny parts of the United States. In general, areas with lower overall solar resource also have less DNI as a part of that total solar resource, or global insolation. The common barometer to determine the cost-effectiveness of any solar
technology is the LCOE (levelized cost of electricity). This metric calculates the cost of electricity based upon capital outlay, solar radiation, system efficiency, and numerous other factors that depend upon the specific details of system hardware, financing, and incentives. Since CPV systems tend to produce more power than flat plate systems in areas with high DNI, the LCOE calculation would favor CPV more frequently in these areas. For example, Fort Worth, Texas, and Dodge City, Kansas, receive roughly the same amount of global insolation, yet Dodge City has 15% more DNI than does Fort Worth. Therefore, an LCOE analysis comparing a specific pair of PV systems might favor the CPV system for Dodge City and the flat-plate one for Fort Worth. However, if the economic parameters for either system are changed, the LCOE analysis could favor the CPV or the flatplate one for both locations. Why CPV systems use expensive cells The best CPV sites have a high DNI, but since they have more direct sunlight these sites generally have higher ambient temperatures. Unfortunately the efficiency of photovoltaic cells decreases with increasing temperatures. To make things even worse, concentrated sunlight generates significant heat. Silicon cells lose between about 0.4% of their maximum power for every Celsius degree of temperature increase while III-V cells lose only about 0.2%. Therefore, III-V materials are a better fit for CPV than silicon. There is another good reason to select III-V cells. Multijunction PV cells can be manufactured with III-V materials. These multijunction cells have two or more junctions, each one generating power from a different wavelength of light, so more of the available light can be converted into electricity. Although the efficiency of a single-junction silicon cell in concentrated light is theoretically limited to about 30%, multijunction III-V cells already boast efficiencies higher than 40%, a number that is expected to increase over time as this technology advances. Concentrated sunlight also increases the efficiency of a cell, and multijunction cells under concentrated light have been shown to surpass 40% efficiency at 25º Celsius. As a rule of thumb, efficiency increases by 2% for every 10x increase in concentration. Multijunction cells are significantly more costly than are silicon cells, at prices of around $5-10/cm² versus a typical silicon cell price of about $0.10-0.20/cm².
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24th EU PVSEC Hall B5/Stand 61
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Booth 189
Global Solar Technology – April 2010 – 9
New survey outlines challenges and opportunities for CPV
Since multijunction cells are about twice as efficient as their silicon counterparts, and since they maintain their efficiency at higher temperatures, they are more commonly found in HCPV systems than are silicon cells, but the significant price difference between the two technologies is only overcome because of the unique cost dynamics of HCPV systems. It’s cost per watt, rather than cost per cell area, that is the important measure and a 500-sun CPV system consumes 1/500th the area of PV material as does a flat-plate system. This means that even if III-V cells cost 50 times as much as the same area of silicon cells, the cost of the cells in the III-V concentrating system will be 1/10th the cost of the cells of the same size flat-plate silicon system even before efficiency differences are taken into account. One of the most important reasons that multijunction cells are commonly found in HCPV systems is the fact that the cells in an HCPV system account for a very small portion of the total system cost. Switching to the more expensive multijunction cells results in a system that produces twice as much power as could be produced by the same system with silicon cells. Since the cells are a small part of the overall system cost, today’s HCPV systems universally find multijunction cells to be the preferred option. Another way to look at this would be to consider how the cost of a certain wattage system could be reduced through the use of more efficient cells. The cells in a CPV system constitute such a small part of the total system cost that a substantial increase in the cost of the cells becomes vastly overshadowed by the savings generated in the rest of the system. The amount of materials, optics, and tracking per watt is cut in half by doubling the efficiency of the cells. Even so, today’s largest CPV installation, the Parques Solares de Navarra near Villafranca, Spain, (Figure 6) was installed in 2008 using silicon cells. The manufacturer of these systems, Guascor Fotón, is working on a follow-up design that is based on multijunction cells. Suppliers Significant attention was drawn to CPV in 2007-2008, when purified silicon supplies tightened, and prices subsequently spiked. The value proposition of any alternative technology was stronger during that time than it is today, now that purified silicon is in an oversupplied state. During the shortage roughly 70 CPV
10 – Global Solar Technology – April 2010
companies were launched, each with its own solution to the challenges of this technology. The following list, condensed from an exhaustive survey of CPV firms conducted by EPRI categorizes a number of firms according to four broad categories: Reflective LCPV, Refractive LCPV, Reflective HCPV, and Refractive HCPV. Companies are listed in alphabetical order. Those companies that participate in multiple categories are listed more than once.
Solar, Daido Steel, Delta Electronics, EMCORE, ENEA Portici Research Center, Energies AC Gava, Energy Innovations, EnFocus Engineering, ES System Co., Everphoton Energy, Green and Gold Energy, Guascor Fotón, Helios Solar, Isofotón, MST, OPEL Solar, Pyron Solar, Renovalia CPV (formerly Concentración Solar La Mancha), Semprius, Sharp, Silicon CPV, SolBeam, sol3g, Solartec International, Soliant Energy, Square Engineering, SUNRGI, Sunseeker, Telicom, Xtreme Energetics.
Reflective LCPV Abengoa Solar, Absolicon Solar Concentrator, Banyan Energy, Covalent Solar, Greenfield Solar, Heliodynamics, JX Crystals, MegaWatt Solar, Menova Energy, Morgan Solar, Pacific Solar Tech, Pythagoras Solar, SHAP SpA (Solar Heat And Power), Silicon CPV Skyline Solar, Solar Systems Group, Stellaris, SV Solar, Whitfield Solar, WS Energia, Zytech Solar.
CPV is a multidimensional problem, and as such it requires strengths in a number of different disciplines. Many of the CPV companies that have not yet entered mass production have a solution for only one or two of these challenges, and it is likely that they will not be able to progress into volume manufacturing without gaining strength in those disciplines in which their current experience is weak. Details on some of these disciplines are listed below:
Refractive LCPV CPower, Entech Solar, Prism Solar Technologies (PST), Solaria, Taihan Techren Reflective HCPV Concentrating Technologies, Cool Earth Solar, GreenVolts (based on previous design), Intinergy, Solar Systems Pty, SolFocus, United Innovations, Zenith Solar. Refractive HCPV Abengoa Solar, AEST, Amonix, Arima EcoEnergy Technologies, Beghelli, Compound Solar Technology, Concentrix
• Concentration: There are several routes to concentrating sunlight – and varied opinions as to the degree of concentration that is best. The two basic types of concentration are reflective and refractive. Reflective concentrators include parabolic troughs, parabolic dishes, heliostat arrays, and simple flat mirrors. Refractive approaches are typically based upon Fresnel flat or domed lenses which are usually molded either in free-standing acrylic or silicone attached to a glass support.
Figure 6. The Parques Solares de Navarra, with Guascor Fotón. Panels designed by Amonix.
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New survey outlines challenges and opportunities for CPV
• Heat Dissipation: Since concentrated sunlight produces significant heat, and since the strongest sunlight is likely to occur on those days with the highest ambient temperature, a good deal of attention must be devoted to a means of cooling the cell. For reasons of cost CPV designs use passive air cooling in most cases. Passive cooling is not only cheaper to manufacture, it is also cheaper to maintain than actively cooled systems. • Tracking: As a general rule, the higher the concentration, the smaller the sunlight-acceptance angle of the receiving array. LCPV systems can often use a simple single-axis tracking system that matches the tilt of the receiver to the elevation of the sun. HCPV systems require more sophisticated 2-axis trackers that track the sun precisely. Since many HCPV systems have acceptance angles of only about ±1º, the tracking system must support this level of accuracy, despite wear, for the life of the system (typically 20 years), while being robust enough to withstand strong winds and other difficult weather conditions. • Alignment: Because of the acceptance-angle issues mentioned above significant design efforts must be dedicated to concerns of manufacturing alignment, thermal expansion, stress, and other factors that might move the system’s focal point or increase or decrease the focal length of the array. Since a number of today’s suppliers have novel solutions for only one or two of the above challenges, we consider it highly likely that certain CPV companies will merge to assimilate each firm’s strengths in their own area of expertise. Conclusion Concentrating photovoltaic systems are a very young business with promise in areas of the world with a high DNI resource. Currently there are many suppliers with a very broad range of solutions and unique core competencies but with relatively few deployments. In the future, as companies with complementary core competencies consolidate, there will be fewer suppliers providing a much narrower range of more robust solutions. As the technologies mature and the economies of scale bring costs to a more competitive level the CPV market has the potential to develop into a meaningful part of the world’s power generation capacity.
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Global Solar Technology – April 2010 – 11
Improvements at the absorber layer needed to keep thin-film silicon PV alive in the marketplace
Improvements at the absorber layer needed to keep thin-film silicon PV alive in the marketplace Thin-film silicon (TF Si) photovoltaics has been around for a long time, but went through boom times during a period when there wasn’t enough crystalline silicon to satisfy demand by the PV industry; TF Si uses about one-hundredth the amount of silicon used by crystalline silicon PV. The most mature of the TFPV technologies, TF Si, currently accounts for about 43 percent of the TFPV market. But now that the silicon shortage is over, TF Si PV has to compete on its own merits at a time when CIGS and CdTe PV offering a compelling alternative. Such technologies offer the same lightweight and small form factor as TF Si but with higher conversion efficiencies. CdTe has the lowest cost-per-megawatt of all TFPV technologies. CIGS PV, on the other hand, offers the highest efficiency of all TFPV technologies-20 percent for champion cells. While there may be some niche applications in which TF Si offers some benefit over the other TFPV technologies, only cost and/or performance improvements will help it hold onto its market share. NanoMarkets suspects these improvements—if they come at all—will arrive through changes in the absorber layer. We believe that there are four specific technical directions from which these improvements might emerge: multijunction cells, cells using micro-silicon materials, cells using nanocrystalline silicon and printed silicon. Multi-Junction Cells: Today, most TF Si PV is based on amorphous silicon (a-Si). One reason for the low efficiency of a-Si PV is its bandgap, which is in the range of 1.7-1.9 eV-higher than ideal for a singlejunction cell. But a-Si also suffers from the Staebler-Wronski (S-W) Effect, which causes significant degradation in the
12 – Global Solar Technology – April 2010
power output of the cell when exposed to the sun, on the order of 15 percent to 35 percent. While making the layers thinner can reduce the impact of the S-W Effect by increasing the electric field strength across the material, the result would also mean a reduction in light absorption and in the (already low) efficiency of the cell. To counter these effects, several a-Si PV firms have started manufacturing multijunction cells up to triple junction as a way to boost a-Si PV’s performance. Stacking thin layers on top of one another to form multi-junction cells improves performance on several counts. These layers are less susceptible to the S-W effect and the high bandgap of a-Si in the top cell lets a large proportion of light through to the next underlying cell, allowing the underlying cell, which typically uses a-SiGe to lower its bandgap, to generate significant current. This approach represents a significant improvement over a simple a-Si cell, but there are also drawbacks. Specifically, the multi-junction approach adds costs in (at least) two ways. First there is the additional cost of the germanium for alloying. Then, more significantly, there is the increased complexity of the cell adding more cost and reducing yields. Multi-junction cells of this kind can boost a-Si’s conversion efficiency to about 12 percent in champion cells or 10 percent for mass-produced, commercial cells. But there is diminishing marginal utility in this approach, not just in money terms but also in terms of performance, since each successive junction adds less to the overall performance of the cell. Microcrystalline silicon: While a multijunction TF Si PV structure using a-SiGe alloy for the underlying cells provides a much-needed performance boost, a similar
boost can be obtained at lower cost by using microcrystalline silicon (µc-Si) as the lower absorber. The bandgap of µc-Si is about 1.1 eV, similar to that of bulk c-Si and a good complement as the bottom absorber to an a-Si top absorber. Using µcSi combines the stable, higher efficiencies of c-Si technology with the simpler and cheaper large-area deposition technology associated with amorphous silicon. In addition, µc-Si uses very similar processing to a-Si and µc-Si cells can be fabricated on identical equipment to that used for a-Si. This means that there would be no need for a major changeover in manufacturing infrastructure if a firm shifts from a conventional a-Si to a µc-Si product. And the likelihood is that cell makers may want to make that change since µc-Si may be more robust than a-Si cells and because-at least according to one companyµc-Si can offer an increase in power over conventional a-Si PV cells. Of course, as usual, nothing comes without a cost. The key issues for µc-Si from a technology viewpoint are control of the morphology and size distribution of the deposited µc-Si. Any changes to the size distribution or the balance between crystalline and amorphous composition will change the properties of the film and hence the efficiency of the cell. Because this process window is very small, advanced manufacturing techniques and process control procedures borrowed from the semiconductor and display manufacturing industries are key to success with µc-Si cells and naturally this adds cost. Nanocrystalline silicon: While multijunction cells and µc-Si cells are fairly established technology, a more speculative approach to improving the performance of TF Si PV cells is to shrink the sizes
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Improvements at the absorber layer needed to keep thin-film silicon PV alive in the marketplace
Tandem a-Si/µc-Si cells from Astroenergy. (Source: armeninchina.com)
of the silicon particles to the nano scale, a natural extension beyond µc-Si. Specifically, nanocrystalline silicon (nc-Si) holds potential for improvements beyond those achievable with µc-Si because below about 100 nm in diameter the properties of silicon crystals begin to change. At very small sizes-around 5 nm or sonanoparticles become “quantum dots.” Prepared properly, silicon quantum dots can generate more than one exciton upon absorption of a high-energy photon. Conventional absorbers only generate one exciton and any excess photon energy just creates heat. Multiple exciton generation (MEG) is the feature that could allow nanosilicon PV to reach remarkable
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efficiencies-50 percent is talked about as a reachable goal. Such efficiencies would fundamentally change the value proposition of PV, but no one expects them to appear in a commercial product for many years. Printed silicon: Beyond nanocrystalline silicon are silicon inks for printing—a natural extension of using nc-Si, which can fairly easily be turned into inks. What printing offers is a fabrication approach that is much less expensive than more conventional approaches. Current deposition methods such as CVD, laser deposition, and plasma methods, are expensive, requiring vacuum chambers,
high energies and temperatures, and they are often inefficient in terms of material usage. Printing of silicon aims to eliminate most or all of these issues, reducing costs as well as enabling a wider variety of substrates and applications. Another key advantage of the silicon inks-particularly the ones made with nanocrystals-is that it is possible to tailor the composition and size distribution of the nanocrystals in the ink to optimize the performance of the printed films.. Varying the composition of ink particles may enable the cell to absorb a wider spectrum of light with a single film compared to the multiple junctions necessary with traditional highperformance a-Si PV cells. But these advantages, while significant, are not yet the focus of printed silicon PV. For now, the goal is to obtain similar performance to conventionally deposited silicon while entering a new realm of scalability and cost reduction. And printed silicon PV has a long way to go. For one thing, functional printing of all kinds is harder to implement than the textbooks suggest. Whether all this is enough to “save” thin film silicon in an era of silicon abundance remains to be seen. However, there is little doubt that silicon PV will still be a major part of the TF PV market for many years to come, although soon the average silicon cell will have structures and chemistries that look nothing like the a-Si cells of years past, such as those used in pocket calculators. This report was provided by NanoMarkets. www.nanomarkets.net
Global Solar Technology – April 2010 – 13
Looking into the US Department of Energy’s “Solar America Cities” program
Looking into the US Department of Energy’s “Solar America Cities” program In Global Solar Technology we usually focus on the engineering issues—how to improve performance, throughput, cost and quality. From the end-user’s perspective though, that can be less important than the hurdles they need to jump to actually get a system installed. Permitting and financing can be a nightmare for both commercial and residential customers. Here we outline one program from the US Department of Energy that is addressing these issues and talk to one of the National Laboratory representatives charged with making it happen. Solar America Cities The Department of Energy’s Solar America Cities program is built upon partnerships with 25 large U.S. cities to develop comprehensive, citywide approaches to increasing solar energy use. The cities are developing innovative solar financing mechanisms, streamlining permitting processes and updating building and zoning codes to make solar a more viable energy solution for residents and businesses. The need Solar market analysts break PV system costs into three categories: module costs, “hard” balance of system costs such as racking and mounting hardware, and “soft” balance of system costs such as permitting fees and installation labor. According a recent LBNL (Lawrence Berkeley National Laboratory) report available at http:// eetd.lbl.gov/ea/emp/re-pubs.html, the recent decline in installed system costs is primarily the result of a decrease in PV module costs, which can be attributed to expanded manufacturing capacity in the solar industry in combination with the global financial crisis—driving the costs of
14 – Global Solar Technology – April 2010
Figure 1. Cost breakdown of components in residential and commercial PV systems. Source: “Tracking the Sun II: The Installed Cost of Photovoltaics in the U.S. from 1998-2008” by Ryan Wiser, Galen Barbose, Carla Peterman and Naim Darghouth.
wholesale solar modules down. In other words, the solar technology itself is getting cheaper. The following chart, released from the report, illustrates the cost breakdown of components in residential and commercial PV systems. According to the chart, approximately 30% of the cost of commercial PV systems and approximately 40% of the cost of residential PV systems was for overhead, regulatory compliance, and labor—the “soft” balance of system costs. In other words, a significant portion of the cost of PV technologies is a result of complex regulations, state and federal paperwork, and an immature labor market. This is an important finding given the common perception that solar technology itself is very expensive. As technology costs continue to decrease in the coming years, the soft balance of system costs will make up a larger and larger portion of the total system cost, unless industry and
policymakers take action to reduce those soft costs. Addressing the challenges That is where the U.S. Department of Energy’s Solar Market Transformation program comes in. The Department of Energy is investing in solar workforce development, as well as outreach to state and local policymakers, to help update and streamline regulations to support solar market growth. The Department of Energy’s Solar America Cities program, which seeks to increase the use of solar energy in communities across the U.S., has already been successful in reducing the cost of PV systems in certain cities. Training programs for solar installers and code officials, as well as initiatives to decrease permitting time and fees are two examples of how cities can help decrease overall PV system costs.
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Looking into the US Department of Energy’s “Solar America Cities” program
In many cities, the process for obtaining a solar permit has been streamlined to reduce costs. For example, in Portland, Oregon, the city updated solar permitting guidelines, simplifying the process for solar installers and offering a solar permit for residential systems for under $100. In addition, the city’s Bureau of Development Services (BDS) has developed a new electronic permit submittal process for solar installers, making it easier than ever to get residential solar building permits. For qualified projects, installers can now e-mail their permit application to the city and expect a review within 24 hours. The city has also trained staff at the permitting desk as solar experts and has set aside weekly times for solar contractors who need help filing their permits in person. Residential financing options There is a broad perception of high upfront costs associated with solar energy technology installation. Most people are familiar with paying a monthly fee for their electricity, so the prospect of a large upfront investment for a solar installation, even if it represents 30 years of electricity generation, can often be a financial barrier that discourages even those who are highly motivated. Several models for financing solar energy systems and reducing the upfront cost have recently evolved. The most popular new models for consumers
Figure 2. Doug Crockett, member of Tucson’s Solar America City team, amongst a PV array installed at Tucson’s El Pueblo Activity Center. This 100 kW array was financed with Clean Renewable Energy Bonds. Source: Tucson Solar America City Technical Assistance Team.
interested in purchasing solar for their home are property assessed clean energy (PACE) financing programs, residential power purchase agreements (PPAs) and residential solar leasing. These models complement the more traditional use of cash or home equity loan financing for solar installations.
Figure 3. U.S. Department of Energy’s Solar America Cities Technical Assistance Team commissions a 1-MW PV system for the Orlando Convention Center. From l-to-r: Dave Click, Florida Solar Energy Center, Jaya Jackson and Kurt Lyell, CH2M Hill.
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All three of these new financing models have relatively low upfront costs. The “best” model will depend on individual customer’s needs and financial objectives, as well as which incentives are available in a particular market. The PACE (property assessed clean energy) model is a way to finance energy efficiency and renewable energy projects for residential and commercial properties. The PACE model involves the creation of a special clean energy financing district that homeowners and business owners can choose to opt into. For those who opt in, the city or county will finance the upfront investment associated with the solar installation and collect payment from the homeowner as part of the normal property tax collection process. A lien is placed on the property for the value of the improvements and is paid off during an extended period of time, usually a 10 to 20 year period. Under a PACE program, the special lien remains with the house or business when it is sold and the new owner benefits from and pays for the solar energy system going forward. By tying the loans to the property instead of the homeowner, the cost of the system stays with the parties who benefit from the solar energy system’s savings, even if the property is sold. Under a residential power purchase agreement (PPA), a third party (e.g. a solar company) owns and operates a photovoltaic (PV) system located on the homeowner’s roof. The homeowner enters
Global Solar Technology – April 2010 – 15
Looking into the US Department of Energy’s “Solar America Cities” program
into a contract with this third party to buy all of the electricity that the PV system generates over an extended period of time, typically up to 20 years. The third party, as the owner of the system, is responsible for all operations and maintenance of the PV system. As the owner of the system, this third party will take the available tax incentives and local rebates and use them to lower the cost of electricity for the benefit of the homeowner. The homeowner will continue to purchase some electricity from the utility to complement the electricity produced by the PV system. The concept of residential solar leasing is fairly straightforward. Instead of purchasing a solar system, homeowners enter into a contract with the owner of a solar system. They provide little or no money down and agree to make monthly lease payments during a set period of time while consuming electricity. Typically the combined lease payment and monthly utility bill (which pays for power needed when the sun isn’t shining) is competitive with previous electric bills. Meanwhile, the party owning the system benefits from the tax credits and accelerated depreciation of the solar equipment. National Renewable Energy Laboratory (NREL) One really valuable asset that hasn’t always been accessible is the knowledge base and expertise in government labs, in this case the National Renewable Energy Lab in Golden, CO where we talked to
Jason Coughlin, the Solar America Cities project coordinator for NREL. Cities have many questions—technical, logistical, financial—and the Solar America Cities program provides a unique way for them to interact with NREL, other labs, and most importantly each other. Q: So how does the program really work? A: We have 25 cities with different levels of experience in solar installations, ranging from the more experienced such as San Diego and San Francisco to cites starting to implement a solar program such as Milwaukee. They can obtain pump-priming grant funding from DOE, have the opportunity to pick up the phone and talk to technical, finance and other experts at NREL, Sandia, and others, and also have the opportunity to benchmark themselves against other cities in the program at meetings like the one we are holding in Salt Lake City in April. Q: How do you fit in to this program? A: You might be surprised to hear that I’m actually a former corporate banker and my primary role is advising roughly 18-20 cities on the financial aspects of their solar programs. Q: What types of investments are we talking about? A: Often, public sector solar—20kW for a library, 2MW for a water facility. We also
help cities with creating rebate programs, launch PACE financing programs, which involves tax assessment financing where the money is repaid under a property tax assessment. For example, Boulder County might finance a PV system in Boulder for about $15,000 after utility incentives and then attach a lien to the property until the cost of the project is paid back through property taxes. Finally, we assist in the RFP process when solar projects are bid out to developers by the cities. Q: How about zoning, permits etc.—can you really streamline the process? A: Now there can be several issues here. You may need a structural assessment (to make sure your roof can withstand the panel loading) and if that means an engineering report, that could be $500 to start with. You may need an energy audit and the of course, you’ll need a permit. This entire process can take awhile and can bog down a project considerably– unless you come to Portland Oregon where there is a streamlined process where you can get it in 24 hours. So permitting issues are critical to the process and if we can streamline them, make it a more transparent process and reduce costs, we can significantly reduce the time it takes to install a solar energy system. Q: Will there be more than 25 Solar America cities? A: Yes and no! The Class of 2007 is graduating (i.e. as a result of completing their projects) this spring but their knowledge base will be made available to any city that is interested. The grant awards last for roughly 3 years. The 2008 Solar Cities still have another year or so to go until they complete the projects they are working on. Q: Do you get involved with private finance? A: More indirectly than directly—the installers—say Sun Power, Chevron and Solar City will work with the banks active in this area—such as Wells Fargo and US Bank—to set up leasing program, PPAs and other forms of financing. We also spend a lot of time getting the cities up to speed on the various financial options they have to finance their solar projects.
Figure 4. At a Solar America Cities focus group session, Marissa Reno of Sandia National Laboratories demonstrates features in the prototype web calculator for financing solar on government buildings. Source: Sandia National Labs.
16 – Global Solar Technology – April 2010
Q: How did the financing opportunities survive the recession? A: Not well. Many of the tax equity players such as AIG, Lehman and Wachovia hit
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Looking into the US Department of Energy’s “Solar America Cities” program
the wall. Out of 15-20 investors in this group, only four or so remained active through the economic crisis. But this number is increasing again as financial institutions become profitable again and start to need tax offsets. The Treasury grant program was and remains critical in this time period as a bridge source of funding until the financial community returns to the solar industry. Q: Tell me about the Salt Lake City meeting? A: We’ll have dozens of panels over three days on a wide range of topics, from finance to workforce development to solar hot water. There will be plenty of opportunities for networking and interaction, which I think is as critical to the success of this program, as are the actual panel presentations. One of the really interesting areas that I’ve focused on in these meetings is the negotiation process between the city and solar developer as cities are often accustomed to having the upper hand in negotiation with vendors. However, with solar, we try to assist cities create win-win opportunities where the
Figure 5. he Solar America Cities Rocky Mountain region team meets at the Solar America Cities Annual Meeting held in Salt Lake City, Utah, April 15, 2010. The working team includes Department of Energy staff, representatives from Solar America Cities Boulder, Tucson, Denver, Salt Lake City and Salt Lake County, cities’ partners and members of national labs. Source: Doug Crockett, City of Tucson.
needs of both the city and the developer are met. It not, the city may find that the solar developer will seek transactions elsewhere.
It looks like this program itself is a winwin for the whole PV community! Thanks for explaining it to us.
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Global Solar Technology – April 2010 – 17
Structural adhesives: a bonding alternative for solar panels
Structural adhesives: a bonding alternative for solar panels Ian Quarmby and Nicole Wood , LORD Corporation and Kimberly Kayler, Constructive Communication Although PV manufacturing is expanding in the U.S., along with the number of installed solar systems, manufacturers and distributors are continuing to seek out new methods of cutting manufacturing and installation costs. A growing solution that has proven to streamline costs, decrease maintenance, and improve durability and product life expectancy of PV systems is the transition from mechanical fasteners to structural adhesives for PV panel manufacturing and installation. As an alternative to mechanical fasteners, structural adhesives offer the benefits of reduced stress points, leaks and corrosion; resistance to extreme environmental conditions; and enhanced sealant properties. Structural adhesive bonding is an established joining method, proven in a variety of end-use markets, including cars, trucks, specialty vehicles and boats. By switching to structural adhesives, the PV panel industry can realize significant cost savings in both manufacturing and installation.
For the manufacturing of PV panel systems, structural adhesives can be applied between the glass and the metallic or composite frame, and also used to attach the frame to the rack. The structural adhesives are a cost-efficient, durable alternative to mechanical fasteners such as U-bolts and screws.
Manufacturing with adhesives The solar industry has been growing rapidly over the past few years and is well positioned to make a significant contribution to the future energy supply in the United States. There are many areas of solar panel construction where structural adhesives would be a viable alternative to mechanical fasteners including the assembly of PV panels and in the supporting framework structure. In photovoltaic cell production, the active silicon layer is often sandwiched between two glass panels. A metallic or composite frame encloses the panels; the frame connects to a rack or framework structure that supports the panels. The racks may be affixed to single- or dual-active tracking systems that allow the panels to follow the sun.
Furthermore, structural adhesives offer a process-friendly solution that can save time and money, while increasing product quality. Depending on the assembly process or the speed of the assembly process, a manufacturer can apply the adhesives from a manual cartridge or a very sophisticated, high-speed robotic system. Another potential benefit to PV installers and manufacturers is a reduction in inventory. They can replace their huge inventory of bolts, washers and screws with one structural adhesive kit. The cost savings can be significant when using structural adhesives for solar panel assembly and installation, considering the number of mechanical fasteners required to secure an array to a rack or tracking system and comparing that to a single structural adhesive which
18 – Global Solar Technology – April 2010
“For the manufacturing of PV panel systems, structural adhesives can be applied between the glass and the metallic or composite frame, and also used to attach the frame to the rack.”
requires few installation hours and no follow-up maintenance. Saving solar energy According to the SEIA, “the greatest challenge the U.S. solar market faces is scaling up production and distribution of solar energy technology to drive the price down to be on par with traditional fossil fuel sources.” As a less expensive, environmentally-friendly energy source, solar power is slated to become even more prominent in the United States as other energy supplies become more costly and less obtainable. For photovoltaic panel manufacturers, using structural adhesives in place of mechanical fasteners will help them to build a better product, faster, more simply and with less cost. Solar panel installers will find using structural adhesives can eliminate the problem of loosening fasteners while providing the benefits of little or no maintenance and less labor requirements. For the solar energy industry to be really successful, it is imperative that it continues to lower costs, whether at the module level or the installation level. Structural adhesives offer the potential for cost-savings, along with the reassurance of product durability and environmental stability.
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Lux predicts challenging times ahead in solar PV
Lux predicts challenging times ahead in solar PV The latest Lux Research report predicts good news and bad news—strong growth will be preceded by a time of shakeout and a major geographic shift in the industry. Lux predicts that strong demand growth in Asia and the U.S. will push the solar PV market to 9.3 GW, equivalent to $39 billion, in 2010, while continued price reductions will drive it to 26.4 GW in 2015, worth $77 billion. Meanwhile, China will become the world’s largest market for solar in 2015, and not just a major manufacturer, echoing past experiences in the television, PC and cell phone markets where their internal market rapidly exceeded exports. This will happen in an atmosphere of significant bloodletting in the West as solar companies adapt to the new realities of the market. We talked to Ted Sullivan, a senior analyst at Lux Research and one of the authors of the report that paints this scenario. Q: With the current recession and upsets in the solar market, why have we seen so little shakeout in the last two years? A: Most of the Western manufacturers have been sitting on the funds they raised before the recession—and those funds are starting to run out at exactly the time that manufacturers need to invest to increase their output and lower their costs. In Asia, the Chinese government is strongly backing companies like LDK and CGL. Q: What is the new reality? A: For a glimpse of the new reality, we need look no further than Q-Cells and their current woes. They had a billion euros in the bank and 400 million left at year end. They have not been able to take advantage of low cost manufacturing fast enough, they have been tied into high cost polysilicon, and the price of crystalline silicon modules has dropped as far as $3.50 to $4.00 per peak watt for utilities—a 40-50% drop since mid 2008. Plus they invested heavily in a wide range of technologies. That “let a thousand flowers bloom” strategy made perfect sense in a
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Generous returns in leading markets drive growth in 2010 $90
30
$80
2010: 9.3 GW for $39 billion revenue
$70
25
$60 $
20
Revenue $50 (Billion $40 US$)
New solar 15 installations (GW) 10
$ $30 $20
5
$10 $0
0
2005 2006 2007 2008 2009 2010 Installations (GW)
2011
2012
2013
2014 2015
Solar revenues (US$ billions)
Source: Lux Research Solar State of the Market, February 2010 17
market growing rapidly with a shortage of polysilicon, but when the market u-turned, it became another factor dragging them down, as most of these new technologies are cash drains. Q: Why China? A: China has really grasped the alternative energy opportunity. Because the government sees it as a strategic imperative, they are supporting industry on both the supply side and demand side. For example, the “Golden Sun” initiative, 642 MW and $3 billion subsidy (50% direct subsidy) is going exclusively to Chinese manufacturers. The only really major project in China given to outsiders is the First Solar 2GW plant in Inner Mongolia, where the First Solar technology works very well in that low light environment. China has developed excess capacity for polysilicon in reserve, as it has done in the past with steel and aluminum, ready to cope with an upswing when other manufacturers may be reluctant to invest and thereby gain market share.
Q: What does this mean for the solar PV market? A: The consequence is that polysilicon prices will remain low for at least the next five years. That will keep the cost of installations of all types low and stimulate the market for solar PV strongly as we approach grid parity in more and more regions. For more details on this study, visit Lux Research at www.luxresearchinc.com.
Global Solar Technology – April 2010 – 19
Innovating with bio-based backsheet materials
Innovating with bio-based backsheet materials We saw a recent announcement on BioSolar’s Backsheets, based on proprietary bio-based materials technology, designed specifically for crystalline Si solar cell module manufacturers. BioSolar estimates that using BioSolar Backsheets can potentially reduce cost by 50% over traditional backsheet materials. We talked to Dr. David Lee, the founder of the company, about this intriguing development. Q: When was the company formed and what is its goal? A: We formed the company about four years ago with the mission of making solar energy “greener.” Many of the ingredients of a solar module are produced using processes that are not very green in terms of hazardous or pollutant-producing processes currently being used. Through the manipulation of bio-based polymers, however, BioSolar can produce robust biobased components that meet the stringent thermal and durability requirements of current solar cell manufacturing processes. BioSolar materials will eventually be used directly in conventional manufacturing systems, such as injection molding and thin-film roll-to-roll, to create superstrate layer, substrate layer, backsheet as well as module and panel components. Q: How are the BioSolar products different? A: Existing backsheets are made
20 – Global Solar Technology – April 2010
from fluoropolymer plus polyester or fluoropolymer plus polyester plus EVA. Ours are made with Nylon 11, produced from castor bean oil by Arkema using a proprietary process along with a cellulosic material made from recycled cotton. We have our first product in limited production and two others following closely. Q: Where were these products developed? A: Mostly in-house, some with an outside partner on cellulosics. Our CTO, Dr. Stanley Levy, has a long and distinguished career in polymer films, including those used in the solar Industry. Leveraging more than 40 years of experience in material science and processing technology, the BioSolar scientific team has developed a low cost bio-based material that meets the manufacturing and operating requirements of solar modules. Our breakthrough biobased material is a result of our innovative enhancements to widely available bio-based polymers. These new tough bio-based materials will be able to offer the durability and environmental characteristics of conventional petroleum-based plastics, such as electromagnetic properties, mechanical strength, dimensional stability, and the weatherability required by most solar cell applications. In short, by toughening up inexpensive and fragile bio-based materials for solar applications, our breakthrough technology helps to reduce the cost of solar modules.
Crystalline silicon solar cell layers.
Q: How do you persuade module makers to use a new material when they have to offer 25-year warranties? A: All modules have to pass the very stringent UL 1703 or equivalent tests. Our products perform well in these tests, and we have product undergoing tests with many US manufacturers right now. We’ll plan to roll out our other products and get them tested and approved in the USA initially before we take this new product to Europe and Asia.
www.globalsolartechnology.com
VDMA Photovoltaic Equipment: Another significant decrease in turnover
VDMA Photovoltaic Equipment: Another significant decrease in turnover According to VDMA Photovoltaic Equipment, Sales turnover for the manufacturers of components, machinery and equipment for the photovoltaic industry in Germany went down by 28 percent in the third quarter of 2009 compared to the respective quarter of last year. “This has been the first downturn in year-over-year growth we experienced since we started our quarterly industry survey in 2007,” said Dr. Peter Fath, CTO of centrotherm photvoltaics AG and new spokesman of the photovoltaic equipment steering committee within VDMA, the German Engineering Federation. Incoming orders dropped by 69 percent compared to the previous quarter, with a noticeable decline of orders from Asia. Record sales of 2008 are not achieved anymore The slump in orders started during the third quarter of 2008. An intermediate high during the first quarter of 2009 has not resulted in positive turnovers due to displacements and cancellations. “However, the bottom should be reached
now,” said Fath. “Generally speaking the domestic turnover is more robust during this crisis,” added Dr. Eric Maiser, director of the photovoltaic equipment forum within VDMA. “The American market for photovoltaic equipment does not yet meet the ambitious expectations. However, after a complete standstill, incoming orders from America reached last year’s volume.” The average range of orders reported by the participating companies went down to 7.6 production months by the end of September, which is three months above the respective VDMA average. According to estimates, turnover is expected to increase again during the fourth quarter of 2009. “Certainly the record sales of the year 2008 will not be reached again,” said Maiser. “A decrease of ten percent is most likely.” The engineering industry remains key for cost reduction. The conditions for photovoltaics in Germany have changed with the announcement of an
additional 15 percent drop of the feed-intariff recently which will come into effect by April 2010. It is not clear yet whether the machinery industry will profit from the continuously high price pressure on the photovoltaics producers, or whether the number of our clients and thus the tendency to invest will decline. “There is an increasing number of reports from our industry that the order situation has improved during the fourth quarter,” said Fath. “This shows that only investment in up-to-date production equipment helps the manufacturers to cope with cost pressure. German machine makers are forerunners with innovative innovative production solutions. However, in the machinery industry too, there will be winners and losers.” www.vdma.org/pv
Gamma sputtering system. (Source: Surrey NanoSystems)
Cell welding, the first step of the module production process. [Source: Siliken]
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Global Solar Technology – April 2010 – 21
Does the solar industry need high purity performance chemicals?
Does the solar industry need high purity performance chemicals? Scott Schumacher, Peak Sun Silicon
High purity chemicals will become increasingly important as PV manufacturers drive toward grid parity. Keywords: High Purity Performance Chemicals, Phosphorus Diffusion, POCl3
22 – Global Solar Technology – April 2010
The financial crisis of 2009 saw module ASP’s collapse by up to 40% compared to pre-crisis prices seen in 2008. These lower prices have driven module, cell and wafer manufacturers to require lower prices from their upstream suppliers as well as from their process chemical vendors. Throughout the solar cell manufacturing process, a variety of chemicals, including HF, HNO3, NaOH, KOH, POCl3, H3PO4, SiH4, and NH3 are utilized. Figure 1 illustrates some of these chemicals and where they are used in the cell making process. It was only a few years ago that solar cells were made using recycled or rejected silicon from the semiconductor industry. These cells were usually made in warehouses and treated with commodity chemicals. Flash forward to 2010, and the industry now consumes more polysilicon than the semiconductor industry—no
more hand-me-downs for us. Furthermore, the cells are processed in clean rooms that rival some of the most sophisticated semiconductor fabs. Why then is the solar industry satisfied with chemicals that are of lower purity than the silicon wafers now in use? To achieve the increases in solar cell efficiency and production yield required to achieve grid parity, the industry must continue to turn to high purity performance chemicals used in texturing, emitter formation, phosphosilicate glass (PSG) removal, ARC deposition and metallization. The remainder of this article will focus on the phosphorus diffusion step and the advantages of using a performance chemical for the solar cell manufacturer. Phosphorus Diffusion The traditional P-N Junction is formed
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Does the solar industry need high purity performance chemicals? Texturing
Acidic HF, HNO3
Emitter Formation
PSG Removal
Anti-Reflective Coating
Metallization
Phosphorus Diffusion POCl3, H3PO4
Chemical Dip HF
CVD SiH4, NH3
Screen Printing and Firing
Alkaline NaOH, KOH
Figure 1. Process flow digram for standard solar cell manufacturing.
by diffusing phosphorus (an N-Type dopant) onto a boron-doped (P-Type) silicon wafer. This diffusion can occur in a batch diffusion furnace using phosphorus oxychloride (POCl3) or in an inline furnace using a spray-on phosphoric acid (H3PO4). It is the formation of the P-N Junction that enables the generation of electricity through the photovoltaic effect. Once a photon hits the top of the solar cell, an amazing series of events must take place for electricity to be created. First, the photon must be absorbed by the semiconductor material. This will only happen if the photon is not either reflected off the surface of the cell, or passed through the cell entirely. Next, the absorbed photons must be converted to charge carriers. Third, charge separation of the carriers must take place within the cell (at the P-N Junction). Finally, the carriers must be extracted as electricity through an external circuit before they are lost through carrier recombination. A significant amount of research has been conducted that has established the correlation between minority carrier recombination lifetime and the ultimate efficiency of the solar cell. This correlation has been demonstrated regardless
of the type of wafer, whether it be monocrystalline or multicrystalline. There are currently several tests available that can be conducted inline on a production solar cell line or offline using a standalone testing unit to test for minority carrier lifetime at each step in the cell manufacturing process. For example, the Quasi-Steady-State area-averaged lifetime measurement method has been proven to effectively predict the ultimate cell efficiency in multicrystalline cells. For more details on this see“Predicting multicrystalline solar cell efficiency from lifetime measured during cell fabrication.”1 It has also been established that impurities found in the silicon wafer or introduced by the phosphorus diffusion process will contribute to recombination and a lower minority carrier lifetime test result after the diffusion process. Specifically, the existence of 3d transition metals have been found to dramatically reduce lifetime. For example, McHugo, Thomson, Perichaud and Martinnuzi found a direct correlation between regions of high concentrations of Iron, Chromium, and Nickel and areas of high minority carrier recombination in multicrystalline cells.2A study by Westinghouse Research Laboratories found that the worst lifetime killers are, in order of decreasing severity, molybdenum, titanium, vanadium, chromium, manganese, iron, aluminum, nickel, copper, magnesium, zinc and calcium.3 Which brings us back to the benefit of high purity performance chemicals. Take for example the guideline specification for POCl3 intended to be used by the solar industry currently promulgated at International Standards Committees by commodity chemical manufacturers: Specifications Assay . . . . . . . . . . . . . . . . . . . . . . . >99.9%
Figure 2. Peak Sun POCl3
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Typical Metals Analysis (ppb) Aluminum . . . . . . . . . . . . . . . . . . . . . . <10 Arsenic . . . . . . . . . . . . . . . . . . . . . . . . <10 Barium . . . . . . . . . . . . . . . . . . . . . . . . <10 Boron . . . . . . . . . . . . . . . . . . . . . . . . . <10
Cadmium . . . . . . . . . . . . . . . . . . . . . . <10 Calcium . . . . . . . . . . . . . . . . . . . . . . . . <10 Chromium . . . . . . . . . . . . . . . . . . . . . <10 Copper . . . . . . . . . . . . . . . . . . . . . . . . <10 Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 Lithium . . . . . . . . . . . . . . . . . . . . . . . . <10 Magnesium . . . . . . . . . . . . . . . . . . . . . <10 Manganese . . . . . . . . . . . . . . . . . . . . . <10 Nickel . . . . . . . . . . . . . . . . . . . . . . . . . <10 Potassium . . . . . . . . . . . . . . . . . . . . . . <10 Sodium . . . . . . . . . . . . . . . . . . . . . . . . <10 Tin . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 Titanium . . . . . . . . . . . . . . . . . . . . . . . <10 Vanadium . . . . . . . . . . . . . . . . . . . . . . <10 Zinc . . . . . . . . . . . . . . . . . . . . . . . . . . .<10 Now look at the data sheet for a high purity performance POCl3 currently being sold by Peak Sun Silicon: Specifications Assay . . . . . . . . . . . . . . . . . . . . . . . >99.9% Purity (Metals Basis) . . . . . . . . . . . . >99.99999% Color (APHA) . . . . . . . . . . . . . . . . . . . . <5 Typical Metals Analysis (ppb) Aluminum . . . . . . . . . . . . . . . . . . . . . . . <1 Arsenic . . . . . . . . . . . . . . . . . . . . . . . . . <3 Barium . . . . . . . . . . . . . . . . . . . . . . . . . . <1 Bismuth . . . . . . . . . . . . . . . . . . . . . . . . <1 Cadmium . . . . . . . . . . . . . . . . . . . . . . . <1 Calcium . . . . . . . . . . . . . . . . . . . . . . . . <3 Chromium . . . . . . . . . . . . . . . . . . . . . . <1 Cobalt . . . . . . . . . . . . . . . . . . . . . . . . . . <1 Copper . . . . . . . . . . . . . . . . . . . . . . . . . <1 Gallium . . . . . . . . . . . . . . . . . . . . . . . . . <1 Gold . . . . . . . . . . . . . . . . . . . . . . . . . . . <1 Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . <3 Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . <1 Lithium . . . . . . . . . . . . . . . . . . . . . . . . . <1 Magnesium . . . . . . . . . . . . . . . . . . . . . . <2 Manganese . . . . . . . . . . . . . . . . . . . . . . . <1 Mercury . . . . . . . . . . . . . . . . . . . . . . . . <5 Molybdenum . . . . . . . . . . . . . . . . . . . . <1 Nickel . . . . . . . . . . . . . . . . . . . . . . . . . . <1 Niobium . . . . . . . . . . . . . . . . . . . . . . . . <1 Potassium . . . . . . . . . . . . . . . . . . . . . . . <2 Silver . . . . . . . . . . . . . . . . . . . . . . . . . . . <1 Sodium . . . . . . . . . . . . . . . . . . . . . . . . . <5 Strontium . . . . . . . . . . . . . . . . . . . . . . . <1 Tin . . . . . . . . . . . . . . . . . . . . . . . . . . . . <1 Titanium . . . . . . . . . . . . . . . . . . . . . . . <1 Vanadium . . . . . . . . . . . . . . . . . . . . . . . <1 Zinc . . . . . . . . . . . . . . . . . . . . . . . . . . . . <3 Real world results While performance chemicals introduce significantly fewer impurities into the silicon wafer, during the diffusion process,
Global Solar Technology – April 2010 – 23
Does the solar industry need high purity performance chemicals? Facility (in MW)
Wafers/Yr
Average Efficiency
Watts/Yr
Cell ASP $/W
Revenue
Commodity Chemical
100
28,571,429
3.500
100,000,000
$1.25
$125,000,000
Performance Chemical
100
28,571,429
3.526
100,750,000
$1.25
$125,937,500
Increase
$937,500
Table 1. Introducing an average conversion efficiency increase of 0.75% has significant effects in a 100 MW cell fab.
the real proof is in the results experienced by customers using high purity chemicals in their production lines. Review for example, the results from the customer below: Carrier lifetime • 156 mm multicrystalline cells • Lifetime measurement ~24 microseconds after standard diffusion • Using performance chemicals vs. commodity chemicals Test results: • 200 reference wafers from tier I vendor • Lifetime using commodity POCl3 = 20.47 ms • Lifetime using performance POCl3 = 28.27 ms • Increase of 17.8% over 6 mo. average existing process • Increase of 38.1% in test conditions
Translating real world results into increased profit While an average conversion efficiency increase of 0.75% (as seen in the example above) may seem insignificant, when introduced across the line in a 100 MW cell fab, the results are significant, as shown in Table 1. At $1.25 per watt ASP, the increase in profit for this 100 MW cell fab approaches $1,000,000 USD. The increase in profit pays for the POCl3 and still results in a significant decrease in cost per watt for the cell manufacturer.
Test results: • FF[%]—Increase of 0.28% • Pmpp[Wp]—Average increase of 0.75% • Pmpp[Wp]—Best cell increase of 1.26%
Conclusion Performance chemicals such as high purity POCl3 can increase carrier lifetime, cell efficiency, and cell fab yield. All of these results can be easily achieved through substituting performance chemicals with low rates of impurities for the commodity chemicals currently used on solar cell lines today. For cell process engineers willing and able to conduct research and development throughout the cell line, even greater results can be achieved. In the drive toward grid parity, performance chemicals will become a critical component utilized by solar cell fabs—and, yes—the solar industry does need high purity performance chemicals!
Through switching from commodity process chemicals to performance chemicals this customer was able to achieve better carrier lifetime after the diffusion process which led directly to an increase in overall cell efficiency. The customer also achieved improved bin distribution and yield. This was all accomplished without modifying and/or improving the diffusion recipe to take advantage of the performance chemical. Experience in working with customers has also demonstrated that a customer willing to perform R&D to maximize the benefit of the performance chemical should be able to achieve even better results as reflected by the large increase in carrier lifetime after the diffusion step.
References 1. Sinton, R.A., “Predicting multicrystalline solar cell efficiency from lifetime measured during cell fabrication”, Proceedings of 3rd World Conference on Photovoltaic Energy Conversion, 2003. p. 1028-1031, Volume 2 2. “Direct Correlation of Transition Metal Impurities and Minority Carrier Recombination in Multicrystalline Silicon” http://www.als.lbl.gov/als/ compendium/AbstractManager/ uploads/Madalsd.pdf 3. Davis, J.R., Rohatgi, A., RaiChoudhury, P. Blais, P., and Hopkins, R.H., 13th IEEE Photovoltaic Specialty Conference, Washington DC. June 1978, p. 490.
Cell efficiency • 156 mm multicrystalline cells • Using performance chemicals vs. commodity chemicals
24 – Global Solar Technology – April 2010
Industry News— continued from page 5
planned reductions with respect to the EEG. Following the regular reduction of 10 % in the compensation for the electricity fed into the grid at the beginning of the year, the new German Environment Minister Röttgen has intended further drastic cutbacks of the compensation rates for solar-generated electricity. Depending on the amount of installed capacity by the end of September 2010, a total decline of about 40 % from the beginning of 2010 until the beginning of 2011 could result. This is a substantial change, of course, of the new government with respect to energy policy. Such a measure threatens the jobs of thousands of employees in the solar sector in Germany with an unpredictable impact on the rest of Europe. The technology will migrate to the cheaper Asian countries. The production and hence jobs will follow. In particular medium-sized companies and suppliers as well as installation companies, which relied on the domestic market and the governmental assertions, will be affected. This will not only impact the solar cell and panel producers but also the engineering sector. The International Photovoltaic Equipment Association (IPVEA) recommends measured and predictable steps relating to changes in the EEG. Modern production technology from Germany and Europe will continue to contribute to the reduction of production costs of solar cells and towards net parity rapidly. The International Photovoltaic Equipment Association is an organization of companies from Europe, the US and Asia. The IPVEA combines machine and equipment manufacturers as well as producers of raw materials used in the production of photovoltaic ingots, wafers, cells (crystalline and thin-film) and panel manufacturers. Solar EnerTech enters into sales contract with Australian Solar Company Solar EnerTech Corp. today announced it has entered into a 15 MW contract with Aussie Solar Installations, a division of Carbon Management Solutions Pty Ltd., one of Australia’s leading distributors of solar power equipment, to distribute the company’s solar panel modules in Australia. Under the contract, Solar EnerTech’s total shipment to Aussie Solar
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Industry News
amounts to approximately US $26 million, which the company plans to deliver in separate shipments before the end of 2010. www.solarenertech.com Sonel commissions the largest Slovenian photovoltaic plant equipped with SolarMax inverters Slovenian wholesaler Sonel has built the largest PV plant equipped with SolarMax inverter in the northern Slovenian town of Gornji Petrovci. With a total capacity of 81 kilowatts, the free-standing system is also the largest in the region Prekmurje. Two SolarMax central inverters with rated capacities of 35 and 20 kilowatts transform the direct current produced by 386 polycrystalline solar modules into gridcompatible alternating current. www.solarmax.com AXT announces 5-year contract for germanium substrate with AZUR SPACE AXT, Inc., was awarded a five-year contract for germanium (Ge) substrates with AZUR SPACE Solar Power GmbH, a leading provider of satellite solar cells for space and terrestrial applications. This contract is the result of a collaboration of the two companies that has enabled AZUR SPACE to obtain an industry-leading 40 percent conversion efficiency rate in average for triple junction CPV solar cells and the 30 percent conversion efficiency rate in average for triple junction GaAs space solar cells. www.axt.com Michigan selected to be site of new DOW™ POWERHOUSE™ solar shingle facility The Dow Chemical Company has chosen Midland, Michigan, as the preferred site for the first full-scale production facility for its revolutionary DOW POWERHOUSE Solar Shingle, subject to finalizing local, state and federal funding. The new facility could bring more than 1,200 jobs to the region by 2014. The Michigan Economic Development Corporation (MEDC) is currently considering up to $140 million in economic incentives for the plant, which would produce the innovative photovoltaic solar panels in the form of solar shingles that can be integrated into rooftops with standard asphalt shingle materials. Local, state and federal funding will help Dow Solar Solutions to accelerate production plans for the solar shingles already being manufactured in a small-scale market development plant at Dow’s Michigan Operations in Midland. If received, the
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MEDC economic package will add to the $100 million in investments Dow has already made in the development of solar solutions since the program’s inception in 2007 when Dow was awarded a $20 million Solar America Initiative Pathways Program grant by the U.S. Department of Energy. The expected growth of more than 1,200 jobs to support the increased solar shingle production will be in the manufacturing, commercial and technical areas, with staffing anticipated to begin in late 2010. DOW™ POWERHOUSE™ Solar Shingles are expected to be available in limited amounts by mid-2010 and projected to be more widely available in 2011 as production scale up begins. www.dowsolar.com French module manufacturer Systovi installs Mondragon assembly line Mondragon Assembly has successfully delivered a module assembly line to the French module manufacturer Systovi. The line has started production in December and has a capacity of 12 MW. Mondragon Assembly, as a turnkey module assembly line supplier, has built a tailor made semiautomatic line, where all the key processes have been automated as tabbing and stringing, bussing and lamination. Systovi’s module is specially designed for the BIPV sector, and Mondragon Assembly’s line has perfectly responded to the requirements of quality and flexibility of this kind of modules: providing flexible line for a wide variety of module sizes and configurations, through its high performance TS600, IC10 and specially built framing station. www.mondragonassembly.com Roth & Rau AG takes over solar activities of the OTB Group B.V. Roth & Rau AG is to take over from the OTB Group B.V., Eindhoven, Netherlands, 100% of the shares in that company’s subsidiary OTB Solar B.V. (OTB). OTB’s product portfolio consists of systems and technologies for the solar industry, especially antireflective coating systems and turnkey production lines for use in the manufacture of crystalline silicon solar cells. Moreover, OTB’s core competencies also include high-rate PECVD coating processes and industrial ink-jet printing applications with interesting potential for use in the production of new, highefficiency solar cells. The acquisition will enable Roth & Rau AG to increase its market share as an equipment supplier for crystalline solar technology and in its turnkey business. The purchase price
amounts to € 35.5 million (including takeover of financial liabilities). Of this sum, an amount of € 30.0 million will be settled by issuing new Roth & Rau shares by way of a capital increase in return for non-cash contributions. The capital increase in return for non-cash contributions will be executed from Authorised Capital II to the exclusion of subscription rights. The new shares will be subject to a lockup period of 16 months following issue. The remaining € 5.5 million will be paid in cash. OTB had orders on hand of around € 50 million as of 31 January 2010. Accounting for the necessary restructuring charge, Roth & Rau AG expects to generate synergy effects in terms of costs and to see positive earnings contributions from OTB from the 2011 financial year onwards. www.roth-rau.de, www.otb-solar.com Evolution Solar establishes Bermuda subsidiary Evolution Solar Corp’s company management has initiated the process of formally establishing a new subsidiary in Bermuda, a step necessary for meeting contractual eligibility requirements under Bermuda law. The company is aggressively seeking to capture opportunities that will be created as a result of the Bermuda Government Solar Photovoltaic Rebate Initiative for residential users. The Bermuda Government desires to move financially and environmentally from current fossil-fuel supplies to non-fossil fuel based energy. Evolution Solar wants to play an important role in assisting in the reduction of dependency on these expensive oil imports. www.evolutionsolar.com Solar Trust of America tests next generation solar thermal collector technology in Southwestern U.S. Solar Trust of America LLC’s whollyowned subsidiary, Solar Millennium LLC, has begun testing its advanced parabolic trough solar radiation collector technology, HelioTrough, at an existing solar power plant in the southwestern United States. The testing is designed to assess performance efficiency under commercial operating conditions before being deployed at proposed solar thermal energy power plants throughout the world. Developed by The Solar Millennium Group’s technology subsidiary, Flagsol GmbH, and its partners, the HelioTrough demonstration “loop” consists of two rows of collectors with a total length of 800 meters and was installed between
Global Solar Technology – April 2010 – 25
Industry News
of collectors with a total length of 800 meters and was installed between September and November 2009. www.SolarTrustofAmerica.com Spire ranked 9th fastest-growing public company in Massachusetts Spire Corporation has been ranked number nine on the Boston Business Journal’s Book of Lists 2010 as one of the Fastest-Growing Public Companies in Massachusetts over the last three years. Spire’s percent of revenue growth from 2006 to 2008 was 240%. www.spirecorp.com SoloPower names Tim Harris as CEO SoloPower, Inc, appointed Tim Harris as president and chief executive officer. Mr. Harris replaces Lou DiNardo who has served as the company’s interim CEO since July 2009. Mr. DiNardo will remain closely involved with SoloPower as its executive chairman of the board of directors. Mr. Harris brings over 20 years of executive experience to SoloPower and will lead the company as it commercializes its innovative flexible solar modules and expands manufacturing capacity to enter highvolume production later in 2010. www.SoloPower.com Linde achieves growth, invests in innovation despite over-capacity in PV industry Defying the impact of a depressed economy on market movements, the Linde Gases Division of The Linde Group closed 2009 with more than 6 GWp (Gigawatt peak) of production capacity across its global photovoltaic customer base. Linde demonstrated increased market traction securing multiple new contract wins and renewals with leading thin-film and crystalline manufacturers worldwide including GS Solar and Suntech in China, Euro Multivision, Indo Solar and Solar Semiconductor in India, and Bosch, Malibu and Masdar in Germany. Linde is training its sights on a promising 2010-11 with an aggressive focus on innovation to help PV module manufacturers to drive down costs and reduce carbon footprint. www.linde.com AREVA to acquire the U.S. solar company Ausra AREVA announced today the 100% acquisition of U.S.-based Ausra, a provider of large-scale concentrated solar power solutions for electricity generation and industrial steam production. This acquisition launches AREVA’s new global solar energy business. Combining
26 – Global Solar Technology – April 2010
Ausra’s proven technology and AREVA’s =engineering, procurement and construction (EPC) skills, the group is committed to building the most cost-effective CSP plants for utilities, independent power producers and industrial customers around the world. This acquisition is expected to close in the next few months, subject to customary regulatory approval. www.areva.com Matheson Tri-Gas and RASIRC sign exclusive distribution deal for RASIRC products Matheson Tri-Gas, Inc. and RASIRC® have signed an exclusive US wide distributor agreement. Matheson Tri-Gas will distribute RASIRC purification and delivery systems throughout the United States. RASIRC designs and manufactures products for controlled humidification and ultrapure steam generation for critical manufacturing processes. www.rasirc.com, www.mathesontrigas.com CNPV signs long-term strategic partnership with Volthaus GmbH China based CNPV Solar Power SAAS entered into a long-term strategic partnership sales agreement with Volthaus GmbH, a south-German leading photovoltaic company in roof top and ground-based power plants project development, installation and distribution company. Under the terms of the agreement, CNPV will supply Volthaus Ltd. with a total of 35 MWp of PV modules from 2010 to 2012, which includes 10 MWp of scheduled delivery during 2010. The remaining 10 MWp and 15 MWp are scheduled for delivery in 2011 and 2012 respectively. www.cnpv-power.com, www.volthaus.com. Siliken doubles the warranty of its photovoltaic modules
Siliken extended the product warranty for its photovoltaic modules from five to 10 years. The measure applies to the materials the modules consist of and to any possible defects caused during manufacture. www.siliken.com
ET Solar Group announces 31 MW module sales agreement with USE ET Solar Group Corp., a Nanjing-based photovoltaic system turnkey solution provider and integrated manufacturer of PV products, announced a 31MW module sales agreement with Umwelt Sonne Energie GmbH (USE) in Germany. Under the contract, ET Solar will deliver a total of 31 MW solar modules to USE in 2010. These modules will be used in USE’s various projects in Germany and other central European countries. www.use-energie.de, www.etsolar.com Day4 Energy signs 10 MW frame agreement with SOLERA sunpower Day4 Energy signed a frame agreement for 10 megawatts with its channel partner SOLERA sunpower GmbH in Southern Germany. The business relationship between the two companies started in 2009 and has been expanding rapidly ever since. SOLERA sunpower has been focused on high quality photovoltaic (PV) solutions for the German market since 2004, The company recently installed 150 kilowatts of Day4 modules on two complete streets of housing developments in Immendingen, Germany. www.day4energy.com, www.solera-sunpower.de Richard Erskine resigns from Ascent Solar Board Ascent Solar Technologies, Inc., announced that Richard Erskine, partner and CEO of Energy Capital Management, is resigning his position as a director on the Ascent Solar board, a position he has held since March of 2008. www.AscentSolar.com AIS receives large order from Bosch Solar Energy AG AIS Automation Dresden (AIS) received a major contract to install its Manufacturing Execution Systems (VPC-MES) in an underconstruction factory in Arnstadt, Germany. The plant will expand Bosch Solar Energy AG’s crystalline solar cell manufacturing capacity to around 400 MWp. The VPCMES is a proven system already in use in four of Bosch’s factories. The amount of the order was not disclosed. AIS is a subsidiary of Roth and Rau AG. www.ais-automation.com, www.bosch-solarenergy.de CNPV signs long-term partnership with Photovoltaic Experts CNPV Solar Power SA entered into a longterm strategic partnership sales agreement with Photovoltaic Experts GmbH, under the terms of which CNPV will supply
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Interview—Jean-Noel Poirier, Global Solar Energy
Interview—Jean-Noel Poirier, Global Solar Energy Jean-Noel Poirier joined Global Solar Energy as vice president of marketing & business development in March 2010. Prior to that, he served as VP of market development at First Solar Inc. He has also held several leadership positions with Honeywell International, including director of worldwide marketing for Honeywell Turbo Technologies, and served as sales leader at SMB, a subsidiary of the Dehon Group in Europe, and market research manager at Rothmans International. We caught up with Jean-Noel recently to talk about his new position. Q: You have a really interesting resume! Tell me about some of the highlights? A: I’ve been fortunate enough to have many good positions in great companies, in positions ranging from manufacturing,
Photovoltaic Experts GmbH with a total of 30 MWp of PV Modules from 2010 to 2012, which includes 5 MWp of scheduled delivery during 2010. The remaining 10 MWp and 15 MWp are scheduled for delivery in 2011 and 2012 respectively. www.cnpv-power.com, www.photovoltaic-experts.com GT Solar announces Richard J. Gaynor as chief financial officer GT Solar International, Inc., appointed Richard J. Gaynor chief financial officer. Mr. Gaynor fills the CFO position vacated by his predecessor in May 2009. Gaynor brings to GT Solar a wealth of financial management experience over the last 23 years at global public technology companies. www.gtsolar.com Solyndra signs agreement with Advanced Green Technologies Solyndra, Inc., signed a distribution agreement with Advanced Green Technologies, a worldwide renewable energy solutions and building-integrated solar energy products provider headquartered in Fort Lauderdale, Florida. www.solyndra.com, www.AGT.com
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turnaround, global marketing, development of “green” products (nontoxic antifreeze), government relations and corporate strategy.
with building materials such as roofing or siding panels makes a lot of sense. And on a building site, having a robust product is very important!
Q: What attracted you to Global Solar?
Q: How easy will it be?
A: Global Solar is positioning itself in an area with clear growth potential—flexible photovoltaics—with only a handful of direct competitors and with an increasing efficiency at 11%, higher than thin film amorphous silicon.
A: We have to get the materials right for the entire installation, and so we will be working with major chemical companies to optimize the materials sets for the different applications. It’s a tough game but with huge rewards.
Q: In our recent interview with Jeff Britt, we learned of some of the unexpected benefits of flexible cells including resistance to damage in shipping. Where do you see the new growth areas?
We wish Mr. Poirier every success in his new assignment!
A: We have to make installations easier and cheaper for customers. Integration Zhejiang Hongchen purchases more solar metallization lines from DEK
Following last year’s purchase of several PV1200 photovoltaic metallization lines from DEK Solar in 2009, Zhejiang Hongchen has purchased more lines from the screen printing specialist. Selected as part of Hongchen’s drive to substantially increase cell production through 2010 and beyond, the DEK lines are renowned for their ability to offer a productivity, cost and lead-time advantage. As DEK’s original award-winning photovoltaic metallization line, the PV1200 is equipped to deliver 1200 wafers per hour throughput for high speed, repeatable solar cell production. Also offering a range of advanced features including dedicated handling for thin wafers, the DEK
Solar line ensures low breakage rates for maximum yield, in addition to high-speed machine vision capabilities. www.deksolar.com Jiangxi Sornid orders more than $20 million in GT Solar furnaces GT Solar International, Inc., and Jiangxi Sornid Hi-Tech Co., Ltd., signed a new contract totaling more than $20 million for GT Solar’s GT-DSS450™ ingot growth furnaces and ancillary equipment and services. Jiangxi Sornid is committed to becoming a leading supplier of high quality multi-crystalline silicon wafers to the solar industry. GT Solar’s ingot growth furnaces produce high quality ingots that meet the expectations of Jiangxi Sornid’s customers. GT Solar is seeing an increase in bookings for the GT-DSS450 furnaces in China as companies begin to add new production capacity to position themselves for the next phase of growth in the worldwide solar industry. With over 1,300 systems in the field, GT Solar’s DSS ingot growth furnaces are widely used in the solar industry and are known for their reliability and for consistently producing high quality crystal. www.sornid.com, www.gtsolar.com
Global Solar Technology – April 2010 – 27
Flextronics ramps up solar capabilities
Flextronics ramps up solar capabilities We recently caught two press releases from Flextronics that made us sit up. First came an announcement about their million plus square foot facility in Malaysia: Flextronics has dedicated one million square feet to create a Clean Tech Super Site at its established facility in Port of Tanjung Pelepas (PTP) Malaysia. This...complements the company’s clean tech strategy that includes providing services to global OEMs of inverters, wind power, smart grid, smart metering, and energy-efficient lighting solutions. Flextronics expects its clean tech super site to result in significant improvements to the industry, including technical advancements for solar products, increased outsourcing among OEMs due to cost and logistics advantages, and overall supply chain optimization. With a range of solar module production services already operational at PTP, Flextronics’ development plans include increasing its site capacity to support one Gigawatt of solar module production over the next two years. Flextronics has established customer relationships with many of the world’s leading clean tech OEMs, including Cree Lighting, Carmanah, Oerlikon, SolarEdge, and Enphase. This was rapidly followed by a second announcement of significant production for Q-Cells: Flextronics will dedicate 200 Megawatts of the capacity at its Clean Tech Super Site in Port of Tanjung Pelepas (PTP), Malaysia, to the production of Q-Cells’ solar modules. This highly strategic location provides Q-Cells with a world-class solution and capitalizes on the solar supply chain that is rapidly evolving in Malaysia. Q-Cells is expected to benefit from an optimized supply chain in terms of product costs and logistics to its end markets, and ultimately a strengthened market position by leveraging Flextronics’ scale and manufacturing expertise. We talked to Dongkai Shangguan, VP and senior fellow at Flextronics.
port facility is near Singapore, convenient for the major shipping lanes, important for economic shipping of solar modules worldwide. We have the space and the ability to ramp from 200 MW to 1 GW as needed.
Solar growth in Asia/ Pacific
A: We’ve had a strong position in Malaysia for some time with multiple sites. This
Growth opportunities are proliferating in the Asia Pacific (Southeast Asia, ANZ and North Asia) solar PV systems market in the wake of declining prices, heightened awareness, favorable policies, and the sustained use of solar power for rural electrification projects. Market trends indicate burgeoning demand from countries such as Australia, Japan, South Korea, Thailand, Malaysia and The Philippines owing to strong governmental commitment to the promotion of solar energy and creation of sustainable cities. Besides commitment from local governments, solar PV systems for rural electrification projects are likely to be driven by increasing active participation of non-governmental organizations, availability of funds from international financial agencies, and involvement of local communities. Urban end-users growing inclination towards adopting sustainable energy solutions has accelerated the adoption of solar PV systems, particularly for roof-tops and buildings, notes the analyst of this research service. Strong government support through policies, feedin-tariff schemes, and other deployment programs has resulted in massive uptake of solar PV systems both for on-grid and offgrid applications. The introduction of feedin-tariff is expected to be a big stimulant for on-grid solar PV system installations for both distributed and centralized solar power plants in countries such as Thailand, Malaysia, Australia, Japan, and South Korea. Market penetration of solar PV systems has been challenged by the high cost of installation as the majority of customers fall under the low-income group. Thus, market growth is heavily dependant on government support in terms of policy guidelines, tax credits, subsidies or rebates. Solar PV systems market growth will
28 – Global Solar Technology – April 2010
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Q: Tell us about the new facility.
Q: The EMS contract manufacturing model has proved very popular with electronics manufacturers worldwide. How does this apply to solar? A: Our business thrives on economies of scale—purchasing, manufacturing and logistics. We have global reach and can set up and reconfigure plants as needed in Europe, Asia, the Americas—wherever customers need us. We benefit their bottom line, their cash flow, their speed to market and above all their balance sheet as they don’t need to invest in the production capacity and infrastructure we already own. Q: When do customers come to you? A: When they are hurting—and that is very much the case in the solar industry right now. Extreme price pressure, increasing volumes and the need to lower costs—that’s the area where we operate best! They can concentrate on what they do best— improving the product—and we concentrate on getting it to the market for them. Q: So it really looks like clean tech is a major emphasis for Flextronics? A: Yes, and don’t forget that there are many aspects to the solar PV supply chain. It’s not just about modules. 30% of the cost is typically in the ancillary equipment. We are also involved in the manufacturing of inverters, CPV, mechanical tracking systems and flexible circuits. —Alan Rae
Giving your metallization process the “OK”
continue to rely on government support until the price reaches grid parity. Moreover, the well-developed power infrastructure deters the use of solar PV systems in some urban areas. The global financial crisis did not have a major impact on the solar PV systems market in the Asia Pacific region. However, due to the ripple effects of the financial crisis on the key global solar power markets, the economic viability of some PV projects diminished because of lack of credit from banks, financial agencies and donor countries. Weak economic conditions have prevented customers from installing expensive onsite power projects. Another factor that contributed to restrained market momentum was the extensive use of diesel fired generator sets and other low-cost renewable energy technologies. To rev up the pace of growth of the solar PV systems market in the Asia Pacific region, it is vital for countries to establish realistic targets, streamline the policy framework, and aggressively boost customer awareness. Going forward, as production costs decline and solar PV systems gain traction, installation costs are expected to reduce and pave the way for largescale commercialization. This, in turn, will attract new entrants across the solar industry value chain. Considering the highly competitive nature of the market, it is imperative for system integration companies to focus on enhancing growth by establishing a strong technical workforce and providing high-quality PV components, says the analyst. Also, participants must ensure on-time delivery of products and provide superior value-added maintenance services to outpace competition.
Giving your metallization process the “OK” ECD just launched their V-M.O.L.E. solar profiling kit and were showing it at the APEX electronics assembly trade show in Las Vegas this month. We talked to Grant Peterson, ECD’s VP of marketing and sales, about profiling as part of the solar manufacturing process.
Spike
Cooling
Burn Out 500°C
0°C
0 (Sec)
10
20
30
40
Typical metallization thermal profile.
temperature and cooling rate. All of these are critical for the properties of the silver metallization and to protect fragile silicon wafers from thermal shock. Q: How are these logged? A: The thermocouple leads are plugged into the V-M.O.L.E unit, which stores the correct profile window and compares the actual to the acceptable ranges. The details can be downloaded and analyzed using the USB link, but the real innovation in the unit is the ‘OK Button’. V-M.O.L.E. solar profiling kit
Q: What is the application? This report was provided by Research & Markets. www.researchandmarkets.com
Typical Metallization Thermal Profile
1000°C
A: Profiling metallization furnaces for crystalline silicon solar cells. Q: What are the major differences between this profiling kit and a solder reflow profiling kit? A: A normal electronics profiler is exposed to eight minutes at 220˚C whereas a solar profiler is exposed to 40-60 seconds at 700-900˚C. The ovens use infra-red rather than convection. We use stainless steel clad thermocouples and a profiler controller that is optimized to protect against infrared by using a polished stainless steel.
Q: The OK Button? A: This is a red or green indicator light that lets the operator know immediately if the profile is OK. Uptime is critical in this business, and the time taken to find a process engineer, download the results and analyze them can make a significant difference. With this system, the universally recognized red/green symbols mean the operator can be empowered to start production if he or she sees the green light. If it is red, our analysis software gives the engineer a ‘dashboard’ to show the profile performance and identify any problem areas. Thanks Grant!
Q: What are the similarities? A: We measure temperature ramp rate, hold time, time above temperature, peak
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Global Solar Technology – April 2010 – 29
New Products Industry News
New products
Schiller Automation’s TS 3600 sets new benchmarks for cell throughput, yield and reliability 3,600 cells per hour with an assured good part yield of 97.3% and a guaranteed operational availability of 95% make the TS 3600 from Schiller Automation currently the highest-performance and most reliable cell tester and sorter of its type. Manufacturers of solar cells using this innovative tester and sorter will demonstrably increase their productivity and reduce the total cost of ownership (TCO). The TS 3600 will enable an annual output of 100 MW to be achieved on just one line for the first time. The prototype of the innovative tester and sorter proved very popular back at the European Photovoltaic Solar Energy Conference (EU PVSEC) and Exhibition in September 2009 in Hamburg. Following further field testing and optimisation of details, this development by the handling and automation specialist from SW Germany has reached the series production stage, and the first orders have already been received. The high cell throughput, reliability, quality of results and lower costs per tested cell will increase the efficiency of production lines and permit more dependable planning. The machine will have paid for itself in less than five years. The line consists essentially of feed,
30 – Global Solar Technology – April 2010
tester and sorter modules. The innovative soft-handling concept and the high precision of the measurement systems used ensure the consistently high performance features, even in long-term daily use. The central conveyor system in the tester unit is based on a continuous conveyor chain. Once the cells are in position, they pass through all the test stations in a fixed, flat configuration. This means the transfer processes, which are otherwise a normal feature of such machines and are critical for the cells, have been largely dispensed with. The performance measurements are carried out by means of a system of guided contacts applying minimum force, guaranteeing optimum measurement results. The outcome is an above-average good part yield and low breakage rates. The compact unit’s flexibility makes it compatible with any solar cell production line, and it can operate in both batch and inline modes. www.schiller-automation.com Increase POCL and in-line solar cell efficiency up to 0.7% absolute One of the main challenges in current solar cell manufacturing in how to increase the Wp output of the manufacturing lines at a competitive cost of ownership. This can either be done by increasing the manufacturing yield/throughput or by increasing the cell efficiency. One of the more common approaches to achieve the former is to use thinner wafers combined
with an inline process. In-line diffusion offers definite advantages over batch (POCL2) systems, in that both yield and overall throughput are considerably higher. To address the latter, Mallinckrodt Baker and ECN launched the ECN-Clean, containing the patented PV-160 Surface Modifier, part of a technology platform that is capable of increasing cell efficiency of both in-line and POCL emitters by up to 0.7% absolute. For more information, contact Mallinckrodt Baker: micro.mbi@ covidien.com. Innovations for PV module production Solar module manufacturers need optimal laminating conditions that ensure that the module is protected against the weather, particularly moisture. Those conditions are today fulfilled by the latest laminating lines from 3S Swiss Solar Systems, which are based on a process with three chambers and enable a 5-minute cycle in the production of solar modules. “With our new laminating process, we have been able to significantly improve the one that has existed until now and achieve a cost-optimised, stable, reliable process with highest throughput,” says Ronald Lange, 3S’s chief innovation officer. “Nevertheless, the future of solar module production will very soon lie in production lines of gigawatt size. For those new dimensions, we are today developing the
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New Products
appropriate machinery concepts by going completely new ways.” Industry insiders are aware of the unique experience of the experts from Lyss, who constantly, and for years now, apply their know-how from their own module production in development of the machines. It is precisely in this profound process-technical know-how that Ricardo Theron, director of production engineering for the solar module producer Solon, sees the key to successful development of production equipment which ensures shorter cycle times with highest quality and reduced costs. www.3-s.ch
Interplex introduces new solar cell receiver package Interplex Engineered Products (IEP), a turnkey, vertically integrated worldclass supplier of application specific thermoplastic electronic packages and a division of Interplex Industries, Inc., has introduced a new solar cell package design for concentrator solar photovoltaic (CPV) devices, now available from suppliers of compound semiconductors and for use by manufacturers, system developers and chip makers requiring high performance, high efficiency interfacing for their CPV cells. The package design incorporates the Interplex unique, patented, dual leadframe design which integrates a thick copper base (heat sink) with a standard lead-frame structure in a high temperature LCP thermoplastic enclosure. This ensures excellent heat transfer from cell to heat sink via the copper lead-frame in order to support increased cell efficiency. The design of the package allows for flexible secondary optics mounting, suiting the
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varied and different module designs that CPV system manufacturers are now considering. It is also designed to have inexpensive interconnect spade terminals for low cost integration of cell systems enabling a lower total cost of assembled receiver due to simplified assembly operations. These packages offer significant advantages compared to the alternative methods of component assembly utilizing direct bond copper (DBC) ceramic substrates or insulated metal substrates (IMS). Thermal management is built in, secondary optics are easily mounted and isolation between cell and system housing
can be achieved very simply with a variety of materials. Furthermore, a packaged cell device allows easier and safer handling, quicker assembly and test of the system as well as simpler repair and replacement, making the designs more future proof as better cell designs and efficiencies are developed. www.interplex.com Schreiner ProTech introduces new, intelligent pressure compensation seal for the solar industry Schreiner ProTech introduced an innovative, rugged, self-adhesive pressure compensation seal (PCS) specially designed to provide solar module junction boxes with long-lasting protection against severe environmental conditions, preventing damage to sensitive electrical components. The new splash-proof PCS membrane vent material delivers permanent weather resistance and prevents the intrusion of water, oil and dust within the junction box housing, even after the component
has been submerged into water for 30 minutes. Condensation, specifically when formed in the photovoltaic (PV) module and transferred into the junction box, can decrease power output and corrode electrical contacts resulting in safety issues. Ideally suited for use with solar power systems, Schreiner ProTech’s new water-repellent membrane ventilates solar module junction boxes, thus reducing the harmful effects of condensation within the housing while offering reliable protection to PV modules that is vital to improving their longevity. While the value of alternative energy sources like solar power is increasing, the production costs of solar energy systems need to be reduced and reliability improved to ensure long-term viability. Schreiner ProTech’s PCS meets the high standards of the IP 67, as well as all of the solar industry’s requirements in terms of cost-reduction, safety, quality and technical performance. Additionally, the PCS can be customized and installed off the roll in a semi- or fully-automated process, enabling leaner manufacturing processes and lower production costs. Schreiner ProTech’s PCS has already been selected by KOSTAL Industrie Elektrik GmbH to be integrated into their PV modules’ junction boxes. www.schreiner-protech.com
Global Solar Technology – April 2010 – 31
Events Calendar 27 April 2010 PHOTONâ&#x20AC;&#x2122;s 8th Solar Silicon Conference Stuttgart, Germany www.photon-expo.com 17-22 May 2010 Solar 2010 Phoenix, United States www.ases.org 24-26 May 2010 PV America Tampa, United States events.jspargo.com 9-11 June 2010 Intersolar Munich, Germany www.intersolar.de
30 June-2 July 2010 PV Japan 2010 Yokohama, Japan www.semi.org/PVJAPAN-EN/
26-28 October 2010 PV Taiwan 2010 Taipei, Taiwan www.pvtaiwan.com
13-15 July 2010 Intersolar North America San Francisco, California, USA www.intersolar.us
27-29 October 2010 DIREC 2010 Delhi, India www.exhibitionsindiagroup.com
2-5 September 2010 Soltec Hameln, Germany www.rainer-timpe.de
17-19 November 2010 PVTech Milan, Italy www.hitechexpo.eu
12-14 October 2010 Solar Power 2010 Los Angeles, California, USA www.solarelectricpower.org
Delhi International Renewable Energy Conference Expo Centre - Expo XXI, National Capital Region of Delhi
27-29 October 2010 l 600 Exhibitors l 5,000 Conference delegates l 250 High profile
speakers l 20,000 Trade Visitors l 40 countries
Upscaling and Mainstreaming Renewables for Energy Security, Climate Change and Economic Development Solar PV | Solar Thermal | Wind | Bio fuels | Bio mass | Hydro | Cogeneration | Geothermal | Energy Efficiency | EVs & HVs
Organiser
Managed by
Exhibitions India Group IOS 9001:2008 & ISO 14001:2004
Government of India Ministry of New & Renewable Energy
Rajneesh Khattar, Tel: +91 11 4279 5054 M: +91 98717 26762; rajneeshk@direc2010.gov.in
www.direc2010.gov.in
Title
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