Module Manufacturing Research Articles

ОПРЕДЕЛЕНИЕ ТЕХНОЛОГИЧЕСКИХ ПАРАМЕТРОВ ОТЕЧЕСТВЕННЫХ ПОЛОВОЛОКОННЫХ МЕМБРАН ДЛЯ РЕШЕНИЯ ПРОБЛЕМЫ КОНЦЕНТРИРОВАНИЯ АЗОТА ИЗ ВОЗДУХА

Membrane Gas Separation Plants based on hollow fibers are actively manufactured and introduced into production abroad. The annual sales of Generon (USA), the world's leading company in delivery of the nitrogen plants, is about 400 units of equipment of capacity to 4000 m3/h. Essentially no hollow fiber for gas separation is produced Russia. At several institutes of the Russian Academy of Sciences performed are research works only. In 2014 JSC Cryogenmash decided to develop an experimental-industrial technique for gas-separation hollow fibers fabrication, as well as to launch the membrane modules manufacturing based on gas-separation hollow fibers for a number of industrial processes: recovery of nitrogen from air, extraction of helium from natural gas and concentration of hydrogen from ammonia production gases. The experimental technology was developed for hollow fibers production of fiber capacity of about 10m/min. Produced are the lots of fibers for nitrogen-from-air concentration. The highest selectivity coefficient reached for O2/N2 pair is within the range of 4,9–5,1, that approaches the characteristics of UBE (Japan) membrane nitrogen modules. Active continuation of works on development of domestic experimental industrial technology is planned for stable manufacture of hollow gas-separation fibers and modules on their basis.

The Fire Risk in Photovoltaic Installations - Test Protocols For Fire Behavior of PV Modules

The fire risk in the photovoltaic systems has emerged over the years as not negligible, setting in motion a process, which involves various organizations (control Authorities, standardization bodies, modules manufacturers, etc.) for achieving the codification of construction, design and installation of these systems and their components to minimize fire risk. Currently, European standards focused specifically on fire behavior of PV modules don’t exist yet, so test protocols focused on other equipment are used to test PV modules reaction to fire. About that, a research program was carried out to do a short analysis of PV systems fire events, to analyze the current test protocols and for identifying their criticalities and possible improvements. In particular, some variants of these protocols have been developed basing on some of the existing test protocols in standard harmonized at European level about reaction to fire of construction products. These variants have been designed for being specific test tools for determination of reaction to fire features of PV modules with main attention to important peculiarities such as: modules inclination, initial fire particularly aggressive.

Photovoltaics towards terawatts – progress in photovoltaic cells and modules

After 30 years of development, photovoltaic (PV) technology has been recognised to be capable of contributing significantly to future energy supply. The global cumulative installed PV power now exceeds 180 GWp, and the annually installed power exceeds 40 GWp. The cost of electrical energy produced by PV systems is now close to that from conventional sources. This study discusses the physics, construction and manufacture of PV cells and modules, taking into account current trends in technology. All parts of PV systems that influence the cost of the electrical energy produced are considered. Three generations of PV module are described. Crystalline silicon (c-Si) is and will remain the dominant PV material at least until 2020 because of its high efficiency, long service time and relatively low cost. It represents nearly 90% of total module production. There are no material supply constraints to limit production and a decrease in c-Si PV module cost to below 0.4 €/Wp before 2017 can be expected. PV power generation will reach industrial grid parity before 2020 and a cumulative installed power of 1 TWp is expected before 2025.

Patents: zeolite membrane: NGK Insulators Ltd

The world’s third-largest maker of solar cells, Japan-based Kyocera Corporation, is planning to increase PV cell and module manufacturing capacity in two production facilities in Japan, and also start manufacturing solar cell-based power-generating panels in Mexico and Europe in the latter half of 2004.Visit www.re-focus.net for the latest renewable energy industry news

Study of the energy balance and environmental liabilities associated with the manufacture of crystalline Si photovoltaic modules and deployment in different regions

For environmental assessment of photovoltaic systems generation from solar power, it is necessary to consider the fact that a sequence of activities must be accomplished in its production process, not only manufacturing but also installation for proper operation. According to the composition of the energy matrix of the country where this is done, a greater or smaller quantity of CO2 emissions will occur, apart from other environmental degradations. In this case the need of verification is evident, considering the energy matrix of the country where a panel is developed or used, its ability to depreciate the energetic cost and the CO2 emissions, as well as the degradations caused by the manufacturing process. After that, if the photovoltaic panel is still capable of functioning then it will be considered as a source of clean energy. This study has therefore surveyed the energetic costs and CO2 emissions of the manufacturing process of photovoltaic modules. Later this data was used to further analyze the energetic and CO2 mitigation balance and the module capacity for mitigating the environmental liabilities caused by production, by considering different production and using panel׳s sites. The results obtained demonstrated that the greater the emission factor of the panel production country, the greater the required time for emissions reduction due to its production. For instance, in case of panels produced in China and used in Brazil, they could have a truly clean useful life (EULT) up to three times lower than those produced in Germany. The implications of these results were discussed.

Determination of the degree of ethylene vinyl acetate crosslinking via Soxhlet extraction: Gold standard or pitfall?

Since the beginning of PV module production, Soxhlet extraction has been the standard method for the determination of the gel content and the resulting calculation of the degree of crosslinking of the most common PV encapsulant ethylene vinyl acetate (EVA). While the method is deemed well established and several pertinent ASTM and ISO standards exist, in practise the actual procedures used in – and trusted by – both industry and R&D institutions vary substantially. To evaluate the reliability of the methods and the comparability of the results, a round-robin test involving seven independent European laboratories – one industrial PV module manufacturer and six R&D facilities – was conducted. The measurements were performed using homogenous, anonymized sample sets, each comprising five differently crosslinked EVA foils. The analysis showed that results obtained for the same samples may deviate significantly, but also that very different analytical procedures can yield comparable values. In a systematic study, the impact of various key parameters of the analytical process (extraction time and solvent, drying conditions, sample size and weight etc.) was investigated. Based on these findings, deviations observed in the round-robin study could be linked to their origins and the main pitfalls were identified. In conclusion, a suggestion for an optimised standard procedure was derived to ensure comparable results at all laboratories.

A Comprehensive Study on the Automation Potentials and Complexities of Advanced and Alternative Die-Attach Technologies for Power Electronic Applications

The field of power electronics packaging presents intricate and interdisciplinary challenges. System costs, reliability and performance are strongly determined by various aspects such as mechanical design, materials, thermal management and interconnect technologies. The overall costs of the product depend mainly on the complete process chain in the module development. Automation as well plays an important role and facilitates higher production rates, efficient use of materials, better product quality, and reduced factory lead times. This paper focuses on emerging interconnection technologies of bonding semiconductor components to power electronic substrates like diffusion soldering, conductive adhesive bonding and reactive multi-layer bonding. An overview on the automation potentials and complexities in individual technologies for the manufacturing of reliable and cost-effective power modules is given and discussed. Thus, a basis is created for choosing optimal die-attach technology depending on economic and technologic demand by comparing the state-of-the-art and advanced technologies.

Metrology of Al2O3 Barrier Film for Flexible CIGS Solar Cells

Flexible Cu (In, Ga) Se2 (CIGS) solar cells are very attractive renewable energy sources because of their high conversion efficiencies, their low cost potential and their many application possibilities. However, they are at present highly susceptible to long term environmental degradation as a result of water vapor ingress through the protective encapsulation layer to the absorber (CIGS) layer. The basic methodology to prevent the water vapor permeation is to combine an oxide layer (e.g. AlOx) coating with suitable polymer substrates. Nevertheless, micro and nano-scale defects can appear at any stage of the coating process thus affecting the module efficiency and lifespan. The main aim of this research paper is to use surface metrology techniques including: White Light Scanning Interferometry (WLSI), Atomic Force Microscopy (AFM) and Environmental Scanning Electron Microscopy (ESEM) to characterise the aluminum oxide (Al2O3) barrier film defects, which appear to be directly responsible for the water vapor permeability. This paper reports on the development of a characterisation method for defect detection based on “Wolf Pruning” method and then correlates this with measured water vapor transmission rates (WVTRs) using standard MOCON® test. The results presented in this paper provided a detailed knowledge of the nature of micro and nano-scale defects on the Al2O3 barrier films which are responsible for water vapor and oxygen ingress. This result can then be used to provide the basis for developing roll-to-roll in process metrology devices for quality control of flexible PV module manufacture.

Thermal Repair of Incomplete Back Contact Insulation (P1) in Cu(In,Ga)Se2 Photovoltaic Thin-Film Modules

We investigate the repair of interruptions in the back contact (P1) scribing line between two Mo back electrodes by thermally induced fractures. The fractures occur during Cu(In,Ga)Se2 (CIGS) absorber co-evaporation, as it is applied in CIGS thin-film module manufacturing and can effectively repair line interruptions of up to about 70 μm. Additionally, we present that a thermal treatment after P1 laser scribing and before CIGS co-evaporation can repair even interruptions of up to 1 mm. The fractures which are required for insulation are only of approximately 4 μm width which indicates the potential for further reduction of the interconnection width in CIGS modules and therefore improvement of the electrical module efficiency.

양면형 BIPV 시스템의 커튼월 적용에 따른 온도 및 발전특성 분석

BIPV system not only produces electricity at building, but also acts as a material for building envelope. Thus, it can increase the economical efficiency of PV system by saving the cost for building materials. Bifacial solar cell can convert solar energy to electrical energy from both sides of the cell. In addition, it is designed as 3 busbar layout which is the same with ordinary mono-facial solar cells. Therefore, many of the module manufacturers can easily use the bifacial solar cells without changing their manufacturing equipments. Moreover, bifacial PV system has much potential in building application by utilizing glass-to-glass structure of PV module. However, the electrical generation of the bifacial PV module depends on the characteristics of the building surface which faces the module, as well as outdoor environment. Therefore, in order to apply the bifacial PV module to building envelope as BIPV system, its power generation characteristics are carefully evaluated. For this purpose this study focused on the electrical performance of the bifacial BIPV system through the comparative outdoor experiments. As a result, the power generation performance of the bifacial BIPV system was improved by up to 21% compared to that of the monofacial BIPV system. Therefore, it is claimed that the bifacial BIPV system can replace the conventional BIPV system to improve the PV power generation in buildings.

Roll‐to‐Roll Slot–Die Coated Organic Photovoltaic (OPV) Modules with High Geometrical Fill Factors

AbstractFlexible semi‐transparent organic photovoltaic (OPV) modules were manufactured by roll‐to‐roll slot–die coating of three functional layers [ZnO, photoactive layer, and poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)] and either the screen printing or inkjet printing of the top electrodes. A poly(3‐hexylthiophene):[6,6] phenyl C61‐butyric acid methyl ester (P3HT:PCBM) layer deposited from non‐chlorinated solvents was used as the absorber layer. The modules were realized by slot–die coating of the layers onto a laser‐patterned polyethylene terephthalate/indium‐tin oxide (PET/ITO) substrate, followed by laser structuring of all coated layers. The top electrodes were realized by high‐resolution printing, which, combined with laser patterning of other layers, enables manufacturing of the modules with high geometrical fill factor (92.5 %). The modules have an active area of 156 cm2, and contain 13 serially interconnected cells. Two semitransparent electrodes (ITO from the bottom and PEDOT:PSS/Ag‐grid from the top side) allow the absorption of photons incident from both sides. The performance of the modules was evaluated and compared among the modules by considering the following factors: (i) roll‐to‐roll slot–die coated vs. spin‐coated layers, (ii) inkjet‐printed vs. screen‐printed top electrodes, (iii) top vs. bottom illumination. The demonstrated technology is one of the proven feasible ways towards industrial manufacturing of the OPV modules.

Process-Integrated Manufacturing and Embedding of Novel Piezoelectric Sensor Modules into Glass Fibre-Reinforced Polyurethane Composite Structures

Due to an increasing use of composite materials in various applications and related open questions concerning structural health monitoring and damage detection, the realisation of function integrating lightweight structures with sensory properties is subject of numerous research activities. Main objective is the transfer of already in laboratory and prototype scale established methods for the integration of sensory elements on serial applications. Here, combining the previously separated processing steps sensor manufacturing, component manufacturing and sensor integration can help to make a significant step forwards. Therefore, as part of the activities in the Collaborative Research Centre/Transregio (CRC/TR) 39, a highly productive spray coat method based on the long fibre injection (LFI) process is developed, which allows the process-integrated manufacturing and embedding of novel piezoelectric sensor modules into fibre-reinforced polyurethane composite structures.Based on studies on the technological implementation of the newly developed process, theoretical and experimental studies for contacting and polarisation of the novel sensor elements are presented. In addition, the characterisation of the adhesion properties of thermoplastic films on the used fibre-reinforced polyurethane composites is part of the presented research to evaluate the possibility of integrating thermoplastic-compatible piezo modules for actuator applications.

Technical and economic assessment of perovskite solar cells for large scale manufacturing

In this paper, we have carried out detailed technical and economic assessment of perovskite solar cells for large scale manufacturing. For ultra-small area of the order of 0.1 cm2, efficiency of 20% or so are reported. However, for area of 25 cm2, the efficiency is about 10%. Based on the photovoltaic module manufacturing requirements of no constraint on the supply of raw materials, low variability of every key process and process-induced defects, low cost of manufacturing, prospects for further cost reduction in the future, green manufacturing, and long-term reliability, there are absolutely no prospects of manufacturing perovskite solar cells. No one has commercialized perovskite solar cells. Thus, contrary to hype in the literature, there is no truth that perovskite solar cells will replace silicon solar cells. We have also examined the role of perovskite solar cells for increasing the efficiency of silicon solar cells and found unsuitable both for two and four terminal device architectures.

Thin Film Solar Cell: Characteristics and Characterizations

In recent decades, due to some urgent and unavoidable issues, such as increasing energy demand, climate change, global warming, etc., the R&D of renewable energies have become inevitable to pave way the sustainable development of human society. In this regard, solar power is widely considered as the most appealing clean energy since there is no other one being as abundant as the sun. The amount of solar energy reaching our earth within one hour equals to the total annual energy need of all of humankind. Since the energy resources on Earth are being exhausted, solar energy have to serve as the main energy source in coming century and beyond. The photovoltaic solar cells developed so far have been based on silicon wafers, with this dominance likely to continue well into the future. The surge in manufacturing volume as well as emerging technologies over the last decade has resulted in greatly decreased costs. Therefore, several companies are now well below the USD 1 W−1 module manufacturing cost benchmark that was once regarded as the lowest possible with this technology. Thin-film silicon, such as hydrogenated amorphous silicon (a-Si), microcrystalline silicon (mc-Si) and related alloys, are promising materials for very low-cost solar cells. Here in this article, a brief description of thin film solar cell technologies followed by deferent state-of-art tools used for characterizing such solar cells are explored. Since characteristics of thin-film solar cells are the main ingredient in defining efficiency, the inherent properties are also mentioned alongside the characterizations.

Efficient prediction of maximum PV module output power through dynamic modeling

This work deals with modeling and maximum power tracking of a stand-alone solar photovoltaic (PV) power generator. Based on extensive literature review, a dynamic model of a solar PV module has been developed, simulated, and validated using model in the loop experimental setup. Effects of parameter variations have been accounted for in the dynamic model. It was predicted from the simulation results that the actual real-time maximum power which a solar PV module can harvest is more than the maximum output power being stated by PV module manufacturers. Further, the true maximum power produced by a PV module is directly proportional to the average output electric energy. The predicted true maximum output power can be harnessed through accurate load matching. A small scale outdoor set up has been established at Tennessee Tech University. Preliminary experimental testing showed that when using appropriate load matching, one can predict and extract as much as 20% average more energy over the period of one month from the PV module than what is currently being projected by commercially available PV modules. The model can also be used for any PV module by modifying the module parameters and is an excellent reference for PV engineers and researchers.

Design Considerations and Measured Performance of Nontracked Mirror-Augmented Photovoltaics

Costs associated with conventional photovoltaic (PV) installations (module manufacturing, mounts, wiring and installation labor, etc.) scale linearly with system area, and prudent design practices for increasing the light harvesting may significantly enhance the power output per unit area and cost per watt. The use of PV modules that have been augmented by the addition of a solar mirror provides an opportunity to improve light harvesting of a PV module and cost-per-watt considerations if the mirror is less expensive than the relative increase in power. In order to harvest greater insolation, an optimized design configuration between a flat-panel module and mirror is necessary for a fixed (nontracked) mirror-augmented photovoltaic (MAPV) system. A series of irradiance and energy harvest calculations were developed to screen various MAPV design configurations. We employed optical ray-tracing simulations to determine irradiance nonuniformities on the fixed MAPV system. The simulated results are compared with outdoor experimental field trial results. Over a three-month period of study, the fixed MAPV system produced 12% more power than an equivalent nonaugmented panel. An adjustable angle mounting system known as “time machine” was used to estimate yearly power production by adjusting the relative position of the MAPV system to represent varying times of the year. Current--voltage ( I – V ) curve tracing of test modules was performed during the field trials on augmented and nonaugmented modules for comparison. The experimental time machine result is in agreement with the irradiance simulation, which shows a gullwing curve of annual power output with peak production on the equinoxes and reduced production on the solstices.

Fast and Nondestructive Detection on the EVA Gel Content in Photovoltaic Modules by Optical Reflection

Poly(ethylene-co-vinyl acetate) (EVA) has been the dominating material in the photovoltaic (PV) encapsulant market for decades, owing to its superior cost-performance balance. To achieve its desired material properties, EVA undergoes a curing reaction during the module encapsulation process. The resulting EVA gel content after encapsulation is an important criterion for the module encapsulation quality control. Normally, the determination of gel content is achieved using a tedious solvent extraction method. In this paper, a fast and nondestructive detection method on the EVA gel content based on the optical reflection is explored. First, the homogeneity of the EVA gel content distribution after the standard EVA encapsulation process is studied. Then, the feasibility of the proposed optical approach applied to transparent modules is investigated. After that, a method is developed to apply it to opaque modules by incorporating a mirror into the module construction. It was found that the haze factor of the reflected light correlates well with the EVA gel content in the opaque modules. This proof-of-concept work could lead to the development of a fast and nondestructive tool for detecting the EVA gel content in both transparent and opaque PV modules, which is promising for integration as an inline diagnostic tool in the module manufacturing line.

Inter‐laboratory comparison of UV‐light sources for testing of PV‐modules

AbstractDurability assessment of materials exposed to natural weathering requires accelerated testing for verification of the ultraviolet (UV) stability, especially for polymeric material. The type approval testing of photovoltaic (PV) modules according to the standards International Electrotechnical Commission (IEC) 61215 and IEC 61646 includes a so‐called UV‐preconditioning test with a total UV dose of 15 kWh/m2 corresponding to natural weathering of about 3 months only. A serious UV test representing the service life needs to apply a much stronger UV‐intensity in a comparable way. Fraunhofer Institute for Solar Energy Systems performed an inter‐laboratory comparison of UV‐light sources in 13 accredited test labs and test centres of major PV module manufacturers. The most important topic was the spectral radiometric measurement of the used UV sources. Another main issue was the comparison with the integral measurements by the sensors used for control of the tests. Errors up to 120% were found. Copyright © 2015 John Wiley & Sons, Ltd.

Maintenance of loading and unloading processes of sea vessels at transportation of compressed natural gas

Analysis of the processes of loading and unloading of sea vessels has shown that they can proceed in critical and subcritical regimes. It is found that constant speed when loading the sea vessels is provided due to pressure gas source by the terms of the process in the critical mode. The process is characterized by constant discharge pressure decrease in gas tanks and gas flow that comes out of them. The maximum speed of the process is achieved by maintaining the critical regime through the phased introduction of the compressors. The defining parameters in determining the diameter of connecting collectors under that provided the necessary speed of the loading process are sources of gas. Collectors that selected taking into their accounting are provided the realization of loading process in the subcritical regime at the final stage in conditions of minimum overpressure of the compressor pressure filling capacity. The obtained results can be used in the design of sea vessels to transportation of compressed natural gas. They can also serve as the basis for the acquisition of individual blocks by using the proposed global manufacturers of CNG modules. Using the tested algorithms it is possible to justify the loading and unloading modes of sea vessels under the terms of individual projects.

Cross Testing Electrically Conductive Adhesives and Conductive Back-sheets for the ECN Back-contact Cell and Module Technology

Abstract ECN set up a cross testing project in which suppliers of electrically conductive adhesives (ECA) and conductive back-sheet (CBS) foils participated. In the component part of the project, combinations of adhesive and foil were characterised for peel strength and contact resistance. The separate components were tested on dot geometry (ECA) and surface structure (CBS). In the module manufacture and testing part, 12 combinations of ECA and CBS were used in 4-cell MWT modules. The modules were tested up to 2000 hours in damp heat and 400 thermal cycles (both tests, 2 times the requirement of IEC61215). Most combinations passed the 5% power loss criterion. One of the conductive adhesives performed well on three different types of back-sheet which is supportive of a robust technology. Other results show that it is important to thoroughly test interesting combinations of ECA and CBS at module level before adding them to the recommended bill of materials.