The recent photovoltaic industry shakeout which started around Q3 2008 has faced the overcapacity, credit crunch, and economic crisis that significantly declined the average selling price by 50 - 65%, including the price of thin-film photovoltaic modules. The changing business environment has put significant pressure on all PV manufacturing technologies but more candidly on amorphous silicon thin-film single-junction module manufacturers to advance and scale up the device efficiency and aggressively drive cost reduction. This paper outlines the approach taken at Moser Baer Photovoltaic Technologies India Limited (PVTIL), including process optimization and device management strategies, to enhance the module efficiency (total area) of the single-junction amorphous silicon quarter size, 1.43m2, substrate as manufactured using Applied Materials’ SunFab line.
The seventh edition of Photovoltaics International was published in February 2010. This edition features a wafering focus from REC Wafer and SINTEF on how to improve cell efficiencies. In addition, EPIA provides in-depth analysis of feed-in-tariff schemes in our Market Watch; and in Cell Processing Fraunhofer ISE overcomes challenges in back-side metallization.
The main goal of the solar industry is to reach grid parity as soon as possible. This can be achieved by reducing the manufacturing costs, by increasing conversion efficiencies and/or by improving the lifetime of solar modules. Driving down the cost of modules is not straightforward. Commercially available PV modules are typically sold with 20-year warranties, and changing these materials for economic reasons requires extensive material testing and recertification of the new module design. In the following sections, we will focus on the cost drivers of module manufacturing processes and how that could evolve into new module designs.
In today’s PV modules, the solar cells are commonly encapsulated in EVA. During lamination EVA undergoes a crosslinking reaction. From a practical point of view, two major interests arise. For quality control purposes, one needs to know the degree of curing of the EVA encapsulant after lamination. The focus in process optimization is on understanding the kinetics of the crosslinking as a chemical reaction. If this is known (and proven), one can predict appropriate crosslinking conditions (i.e. lamination temperature and time) that have to be matched to reach a certain degree of crosslinking. This contribution mostly deals with this latter aspect. DSC as well as DMA data and model-free kinetics were used in this study to establish the kinetics of the EVA crosslinking process. It was found that both techniques adequately predict the degree of crosslinking for any temperature as a function of the curing time.
After staying relatively quiet for much of the past year, thin-film PV manufacturer Nanosolar came out with a full docket of announcements on 9/9/09: the completion of its major panel-assembly factory near Berlin; the start of serial rollto-roll production of its flexible copperindium-gallium-(di)selenide cells in the company’s San Jose facility; $4.1 billion in panel purchases from customers – including some of the world’s largest utility companies; NREL-verified cell efficiencies up to 16.4%; and new technical details of both its printed CIGS cell technology and utility-scale panels.
Despite the fall in silicon prices, wafer thickness continues to be reduced. The handling of thin wafers between 120 and 160µm is under research at the Fraunhofer IPA, where gripper-dependent and independent variables were determined as parameters for the handling process. Diverse grippers are tested on an automated test platform. Among these are grippers that are specifically designed for wafer handling, as well as others that are not but are used for wafer manipulation. The test platform includes several different test and handling equipments and utilizes critical parameters that might be required for achieving a high production rate via shortest cycle times to investigate the impact on thin wafers. The first results of the position accuracy measurement in relation to the physical movement parameters and other industrial key figures in ongoing handling research are presented within this paper.
Building-integrated photovoltaics or BIPV is one form of solar electricity that looks set to dominate the solar market in the coming years. The increase in BIPV installations is already evident in some European countries as governments begin to tweak their policies in order to provide a platform for this technology. The past few months have seen countries such as France and Italy make efforts to up the installation rate of this integrated form of solar, increasing the feed-in tariff (FiT) rate quite substantially for BIPV and lowering it for the more common installations such as roof and ground-mounted systems in order to increase the uptake. This BIPV-dedicated section will focus on the new policies implemented in France and Italy, concentrating on France’s policies as a blueprint for others. It will provide a focus on why governments are so keen to increase incentives in favour of BIPV and what the future implications of this market shift will be.
In most complex manufacturing environments, equipment failures dominate. These failures are commonly referred to as ‘fires’ because of the chaos and damage they inflict on factory operations. For example, a key piece of equipment fails, creating a blockage in the production line. One or more personnel are quickly dispatched to fix the problem. The situation is dire, threatening to slow daily product starts and slip output goals. Those working the problem know this failure is of the utmost importance and know if they can just get the machine at an acceptable level, the stress from management will be lifted. Logic leads these personnel to suspect a specific component, which is then replaced. This paper discusses the best method of ensuring that this ‘patching’ of problems does not become part of the regular maintenance routine.
Thin-film module production has proven itself as a forerunner in the race to drive down costs for photovoltaics. The type of semiconductor material used is the most differentiating factor for thin-film photovoltaics, playing the decisive role for determining which core processes are employed and what type of equipment is used. This explains why discussions related to thin-film costs and technologies usually focus on the semiconductor type. However, the effects of glass production, processing and handling are often underestimated: factors such as scaling, yield, unit cost and total cost of ownership of the equipment are defined by the glass-production side of the industry. This paper discusses the challenges faced in glass washing and handling in thin-film PV production.
As polysilicon producers perform expansions and upgrades to increase production and improve operations, plant safety remains critical. Companies should routinely review their safety policies and effectively plan their projects to ensure uninterrupted product supply and create a safe environment for employees and the communities in which they operate. Both the design and the execution of expansion and upgrades to projects are critical as companies strive for minimal down time so that productivity is not affected. Such hazards and scenarios that may hinder and delay start-up, specifically in relation to polysilicon plants, are highlighted in this paper. Furthermore, the paper outlines how best to avoid these situations, offering methods of execution to achieve the three key measures of success: safety, high purity and minimal downtime.
