Mandy R. Lewis, Silvana Ovaitt, Byron McDanold, Chris Deline, Karin Hinzer
{"title":"Artificial ground reflector size and position effects on energy yield and economics of single-axis-tracked bifacial photovoltaics","authors":"Mandy R. Lewis, Silvana Ovaitt, Byron McDanold, Chris Deline, Karin Hinzer","doi":"10.1002/pip.3811","DOIUrl":"10.1002/pip.3811","url":null,"abstract":"<p>Artificial ground reflectors improve bifacial energy yield by increasing both front and rear-incident irradiance. Studies have demonstrated an increase in energy yield due to the addition of artificial reflectors; however, they have not addressed the effect of varying reflector dimensions and placement on system performance and the impact of these parameters on the reflectors' financial viability. We studied the effect of high albedo (70% reflective) artificial reflectors on single-axis-tracked bifacial photovoltaic systems through ray-trace modeling and field measurements. In the field, we tested a range of reflector configurations by varying reflector size and placement and demonstrated that reflectors increased daily energy yield up to 6.2% relative to natural albedo for PERC modules. To confirm the accuracy of our model, we compared modeled and measured power and found a root mean square error (RMSE) of 5.4% on an hourly basis. We modeled a typical meteorological year in Golden, Colorado, to demonstrate the effects of artificial reflectors under a wide range of operating conditions. Seventy percent reflective material can increase total incident irradiance by 1.9%–8.6% and total energy yield by 0.9%–4.5% annually after clipping is considered with a DC–AC ratio of 1.2. Clipping has a significant effect on reflector impact and must be included when assessing reflector viability because it reduces reflector energy gain. We calculated a maximum viable cost for these improvements of up to $2.50–4.60/m<sup>2</sup>, including both material and installation, in Golden. We expanded our analysis to cover a latitude range of 32–48°N and demonstrated that higher-latitude installations with lower energy yield and higher diffuse irradiance content can support higher reflector costs. In both modeling and field tests, and for all locations, the ideal placement of the reflectors was found to be directly underneath the module due to the optimized rear irradiance increase.</p>","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"32 10","pages":"675-686"},"PeriodicalIF":8.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3811","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bifacial silicon heterojunction solar cells using transparent-conductive-oxide- and dopant-free electron-selective contacts","authors":"Anzhi Xie, Genshun Wang, Yiwei Sun, Haihuai Cai, Xiaoyun Su, Peibang Cao, Zheng Li, Zhexi Chen, Jian He, Pingqi Gao","doi":"10.1002/pip.3810","DOIUrl":"10.1002/pip.3810","url":null,"abstract":"<p>The development of transparent electron-selective contacts for dopant-free carrier-selective crystalline silicon (c-Si) heterojunction (SHJ) solar cells plays an important role in achieving high short-circuit current density (<i>J</i><sub><i>SC</i></sub>) and consequently high photoelectric conversion efficiencies (PCEs). This becomes even more important when focusing on the development of bifacial solar cells. In this study, bifacial SHJ solar cells using a transparent-conductive-oxide-free and dopant-free electron-selective passivating contacts are developed, showing a <i>J</i><sub>SC</sub> bifaciality of up to 97%. Intrinsic ZnO<sub>X</sub> layer deposited by atomic layer deposition was used in this structure, which simultaneously provides negligible passivation loss after annealing and enables a low contact resistivity on the electron-selective contact. With both side finger metal electrodes contact, this bifacial solar cell shows an efficiency of 21.2% under front-side irradiation and 20.4% under rear-side irradiation, resulting in an estimated output power density of 24.1 mW/cm<sup>2</sup> when considering rear-side irradiance of 0.15 sun.</p>","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"32 10","pages":"664-674"},"PeriodicalIF":8.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140829920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andreas Lorenz, Timo Wenzel, Sebastian Pingel, Milad Salimi Sabet, Marc Retzlaff, Florian Clement
{"title":"Towards a cutting-edge metallization process for silicon heterojunction solar cells with very low silver laydown","authors":"Andreas Lorenz, Timo Wenzel, Sebastian Pingel, Milad Salimi Sabet, Marc Retzlaff, Florian Clement","doi":"10.1002/pip.3808","DOIUrl":"10.1002/pip.3808","url":null,"abstract":"<p>Within this work, we investigate the potential to optimize the screen-printed front side metallization of silicon heterojunction (SHJ) solar cells. Three iterative experiments are conducted to evaluate the impact of the utilized fine mesh screen configurations and grid layout adaption (finger pitch) for the front side metallization on silver laydown and electrical performance of the solar cells. With respect to the screen configuration, we compare the performance of a fine-mesh knotless screen to a conventionally angled screen demonstrating an additional gain of Δ<i>η</i> = +0.1%<sub>abs</sub> due to reduced shading losses. Additionally, a grid layout is improved by increasing the number of contact fingers from 120 to 156. Furthermore, the current possibility to push the fine-line printing process for low-temperature pastes to the limit is investigated by reducing the nominal finger width <i>w</i><sub>n</sub> to 20, 18, and 15 μm. It is shown that even the smallest nominal width of <i>w</i><sub>n</sub> = 15 μm can be printed with high quality, leading to an additional efficiency gain of Δ<i>η</i> = +0.15%<sub>abs</sub> as well as a reduction of silver paste laydown by −5 mg. Finally, a batch of champion cells is fabricated by applying the findings of the previous experiments, which results in a maximum efficiency of <i>η</i><sub>max</sub> = 23.2%. Compared to the reference group without optimization, this corresponds to a gain of Δ<i>η</i> = +0.17%<sub>abs</sub>, which comes along with an additional decrease of the silver paste laydown by approximately −2 mg. This emphasizes the significance of consistent optimization of the screen-printing process in terms of cell performance and resource utilization for SHJ solar cells.</p>","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"32 10","pages":"655-663"},"PeriodicalIF":8.0,"publicationDate":"2024-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3808","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140811218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katarina Kovačević, Yifeng Zhao, Paul Procel, Liqi Cao, Luana Mazzarella, Olindo Isabella
{"title":"Interdigitated-back-contacted silicon heterojunction solar cells featuring novel MoOx-based contact stacks","authors":"Katarina Kovačević, Yifeng Zhao, Paul Procel, Liqi Cao, Luana Mazzarella, Olindo Isabella","doi":"10.1002/pip.3812","DOIUrl":"10.1002/pip.3812","url":null,"abstract":"<p>The fabrication process of interdigitated-back-contacted silicon heterojunction (IBC-SHJ) solar cells has been significantly simplified with the development of the so-called tunnel-IBC architecture. This architecture utilizes a highly conductive (<i>p</i>)-type nanocrystalline silicon (nc-Si:H) layer deposited over the full substrate area comprising pre-patterned (<i>n</i>)-type nc-Si:H fingers. In this context, the (<i>p</i>)-type nc-Si:H layer is referred to as <i>blanket</i> layer. As both electrodes are connected to the same blanket layer, the high lateral conductivity of (<i>p</i>)nc-Si:H layer can potentially lead to relatively low shunt resistance in the device, thus limiting the performance of such solar cells. To overcome such limitation, we introduce a thin (<2 nm) full-area molybdenum oxide (MoO<sub><i>x</i></sub>) layer as an alternative to the (<i>p</i>)nc-Si:H blanket layer. We demonstrate that the use of such a thin MoO<sub><i>x</i></sub> minimizes the shunting losses thanks to its low lateral conductivity while preserving the simplified fabrication process. In this process, a novel (<i>n</i>)-type nc-Si:H/MoO<sub><i>x</i></sub> electron collection contact stack is implemented within the proposed solar cell architecture. We assess its transport mechanisms via electrical simulations showing that electron transport, unlike in the case of tunnel-IBC, occurs in the conduction band fully. Moreover, the proposed contact stack is evaluated in terms of contact resistivity and integrated into a proof-of-concept front/back-contacted (FBC) SHJ solar cells. Contact resistivity as low as 100 mΩcm<sup>2</sup> is achieved, and fabricated FBC-SHJ solar cells obtain a fill factor above 81.5% and open-circuit voltage above 705 mV. Lastly, the IBC-SHJ solar cells featuring the MoO<sub><i>x</i></sub> blanket layer are fabricated, exhibiting efficiencies up to 21.14% with high shunt resistances above 150 kΩcm<sup>2</sup>. Further optimizations in terms of layer properties and fabrication process are proposed to improve device performance and realize the efficiency potential of our novel IBC-SHJ solar cell architecture.</p>","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"33 1","pages":"209-218"},"PeriodicalIF":8.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3812","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140798812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Photovoltaics literature survey (No. 191)","authors":"Ziv Hameiri","doi":"10.1002/pip.3809","DOIUrl":"https://doi.org/10.1002/pip.3809","url":null,"abstract":"<p>To help readers stay up-to-date in the field, each issue of <i>Progress in Photovoltaics</i> contain a list of recently published journal articles that are most relevant to its aims and scope. This list is drawn from an extremely wide range of journals, including <i>IEEE Journal of Photovoltaics</i>, <i>Solar Energy Materials and Solar Cells</i>, <i>Renewable Energy</i>, <i>Renewable and Sustainable Energy Reviews</i>, <i>Journal of Applied Physics</i>, and <i>Applied Physics Letters</i>. To assist readers, the list is separated into broad categories, but please note that these classifications are by no means strict. Also note that inclusion in the list is not an endorsement of a paper's quality. If you have any suggestions please email Ziv Hameiri at <span>[email protected]</span>.</p><p>Basnet R, Yan D, Kang D, <i>et al</i>. <b>Current status and challenges for hole-selective poly-silicon based passivating contacts.</b> <i>Applied Physics Reviews</i> 2024; <b>11</b>(1): 011311.</p><p>Quirk J, Rothmann M, Li W, <i>et al</i>. <b>Grain boundaries in polycrystalline materials for energy applications: First principles modeling and electron microscopy.</b> <i>Applied Physics Reviews</i> 2024; <b>11</b>(1): 011308.</p><p>Brinkmann KO, Wang P, Lang FL, <i>et al</i>. <b>Perovskite-organic tandem solar cells.</b> <i>Nature Reviews Materials</i> 2024; <b>9</b>(3): 202-217.</p><p>Roose B, Dey K, Fitzsimmons MR, <i>et al</i>. <b>Electrochemical impedance spectroscopy of all-perovskite tandem solar cells.</b> <i>Acs Energy Letters</i> 2024; <b>9</b>(2): 442-453.</p><p>Kumar R, Puranik VE, Gupta R. <b>Application of electroluminescence imaging to distinguish ohmic and non ohmic shunting in inaccessible cells within a PV module.</b> <i>IEEE Journal of Photovoltaics</i> 2024; <b>14</b>(2): 296-304.</p><p>Mahadevan S, Liu T, Pratik SM, <i>et al</i>. <b>Assessing intra- and inter-molecular charge transfer excitations in non-fullerene acceptors using electroabsorption spectroscopy.</b> <i>Nature Communications</i> 2024; <b>15</b>(1): 2393.</p><p>Chojniak D, Steiner M, Reichmuth SK, <i>et al</i>. <b>Outdoor measurements of a full-size bifacial Pero/Si tandem module under different spectral conditions.</b> <i>Progress in Photovoltaics: Research and Applications</i> 2024; <b>32</b>(4): 219-231.</p><p>Ma F-J, Wang S, Yi C, <i>et al</i>. <b>A collaborative framework for unifying typical multidimensional solar cell simulations – Part I. Ten common simulation steps and representing variables.</b> <i>Progress in Photovoltaics: Research and Applications</i> 2024; <b>32</b>(5): 330-345.</p><p>Tahir S, Saeed R, Ashfaq A, <i>et al</i>. <b>Optical modeling and characterization of bifacial SiN</b><sub><b>x</b></sub><b>/AlO</b><sub><b>x</b></sub> <b>dielectric layers for surface passivation and antireflection in PERC.</b> <i>Progress in Photovoltaics: Research and Applications</i> 2024; <b>32</b>(2): 63-72.</p><p>Li B, Hansen CW, Chen X, <i>et al</i>. <b>A robust I–V curve co","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"32 6","pages":"417-422"},"PeriodicalIF":6.7,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3809","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140641758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. W. Weber, O. Kunz, C. Knaack, D. Chung, A. Barson, A. Slade, Z. Ouyang, H. Gottlieb, T. Trupke
{"title":"Daylight photoluminescence imaging of photovoltaic systems using inverter-based switching","authors":"J. W. Weber, O. Kunz, C. Knaack, D. Chung, A. Barson, A. Slade, Z. Ouyang, H. Gottlieb, T. Trupke","doi":"10.1002/pip.3807","DOIUrl":"10.1002/pip.3807","url":null,"abstract":"<p>Daylight photoluminescence imaging of crystalline silicon photovoltaic modules is demonstrated for modules embedded in rooftop and utility-scale systems, using inverters to electrically switch the operating point of the array. The method enables rapid and high-quality luminescence image acquisition during the day, unlocking efficient performance and quality monitoring without the need to connect specific electrical hardware or to make any modifications to the system wiring. The principle of the measurement approach is discussed, and experimental results from a 12-kW<sub>DC</sub> residential rooftop system and from a 149 MW<sub>DC</sub> utility-scale photovoltaic power plant are presented. Measurements were performed using commercial inverters without modifications to the inverter hardware or firmware. In the case of the utility-scale power plant, the daylight photoluminescence image acquisition of modules connected to a central inverter was obtained from a remote piloted aircraft. Data analysis includes the conversion of photoluminescence image data into implied voltage differences.</p>","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"32 9","pages":"643-651"},"PeriodicalIF":8.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3807","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140665299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ning Song, Nathan Chang, Angus Gentle, Yiyu Zeng, Yajie Jiang, Yanfang Wu, Shuo Deng, Yuhao Cheng, Jialiang Huang, Zibo Zhou, Mark Keevers, Martin A. Green
{"title":"Multifunctional coatings for solar module glass","authors":"Ning Song, Nathan Chang, Angus Gentle, Yiyu Zeng, Yajie Jiang, Yanfang Wu, Shuo Deng, Yuhao Cheng, Jialiang Huang, Zibo Zhou, Mark Keevers, Martin A. Green","doi":"10.1002/pip.3805","DOIUrl":"10.1002/pip.3805","url":null,"abstract":"<p>Silicon (Si) solar modules account for 95% of the solar market and will continue to dominate in the future.<span><sup>1</sup></span> The highest efficiency so far for a commercial Si solar module is ~24%.<span><sup>2</sup></span> This means that 24% of the solar energy that reaches the module can be transferred into electricity and the rest is either reflected or absorbed and transferred into heat that warms up the module. Si solar modules typically operate at 20–30 K above ambient temperature under bright sunshine when mounted in the field and an extra 10–15 K higher when roof-mounted. The temperature increase not only reduces energy production by 0.3–0.5%/K (9–15% for a 30 K increase) but also accelerates thermally activated degradation, reducing module life. Therefore, it is important to keep the module operating temperature as low as possible.</p><p>A number of strategies based on active and passive methods for solar module cooling have been proposed to mitigate the elevated module operating temperature, including optical designs to increase the sub-bandgap sunlight reflection<span><sup>3</sup></span> or to increase the emissivity in the mid-infrared range (4–25 μm) and therefore enhance radiative cooling of the module.<span><sup>4</sup></span> Because the current commercial Si solar cells and cover glass already have a high thermal emissivity, further improvement to the actual cooling effect of radiative cooling is limited. The most effective way that has been identified so far is using a band filter for spectral management.<span><sup>5-7</sup></span> For several decades, coatings with low visible light reflection but high sub-bandgap reflection have been used in space applications for cell cover glass. As early as 1963, designs with over 40 dielectric layers were reported, demonstrating their effectiveness.<span><sup>8, 9</sup></span> Recently, there has been a growing interest in applying similar designs for terrestrial use. These designs, which consist of 4 to 45 layers facing the air and incorporating multiple materials, have been reported.<span><sup>3, 5, 10, 11</sup></span> Before deployment of similar designs in the terrestrial PV industry, concerns must be addressed about the feasibility and economics using current fabrication methods and the high durability requirement in the harsh operating environment to which terrestrial modules are exposed.</p><p>The most common commercial PV coating consists of a ~100 nm single-layer antireflection coating (ARC) of nano-porous silica deposited onto the solar glass cover via sol–gel roller coating followed by a high-temperature sintering and tempering process. The porous structure of the ARC aids anti-reflection (by reducing its effective refractive index), but it also reduces the hardness and durability of the coating. In many applications and climates, regular module cleaning can improve system economics but results in abrasion of the ARC. Industry feedback suggests that the majority of abr","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"33 1","pages":"200-208"},"PeriodicalIF":8.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3805","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140675528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Henning Helmers, Eduard Oliva, Michael Schachtner, Gabriele Mikolasch, Luis A. Ruiz-Preciado, Alexander Franke, Jonas Bartsch
{"title":"Overcoming optical-electrical grid design trade-offs for cm2-sized high-power GaAs photonic power converters by plating technology","authors":"Henning Helmers, Eduard Oliva, Michael Schachtner, Gabriele Mikolasch, Luis A. Ruiz-Preciado, Alexander Franke, Jonas Bartsch","doi":"10.1002/pip.3804","DOIUrl":"10.1002/pip.3804","url":null,"abstract":"<p>The optimization of III-V-based photovoltaic cells involves addressing the trade-off between optical losses due to grid shading and electrical losses due to series resistance. In this work, we overcome the boundary conditions of this optimization problem by increasing the grid line height. Contrary to a few micrometer high evaporated metal grid lines, distributed circuit modeling of 1-cm<sup>2</sup> GaAs photonic power converters suggests that 15-μm high grid lines yield the best performances, especially for high-current operation in the 1 to 10 A cm<sup>−2</sup> range. We have successfully implemented a silver plating process into the fabrication scheme of these devices. Current–voltage measurements under intense illumination demonstrate fill factors above 80% at currents up to 35.8 A, highlighting the capability to extract such high currents without major series resistance losses. Under equivalent monochromatic input power of 62.6 W, this results in a maximum power output of 35.5 W from the 1-cm<sup>2</sup> single-junction photovoltaic cell. This development enables optical power links with largely increased power densities, reducing the material demand of precious semiconductors and associated costs.</p>","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"32 9","pages":"636-642"},"PeriodicalIF":8.0,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3804","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140610585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design for the environment: SHJ module with ultra-low carbon footprint","authors":"Timea Béjat, Nouha Gazbour, Amandine Boulanger, Rémi Monna, Renaud Varache, Jérôme François, Wilfried Favre, Charles Roux, Aude Derrier, Eszter Voroshazi","doi":"10.1002/pip.3803","DOIUrl":"10.1002/pip.3803","url":null,"abstract":"<p>The photovoltaic (PV) industry is reaching an inflection point to become a major source of energy. Last decades brought important technical progression in modules' yield and durability. Already available technical solutions might reach the highest power output and the lowest environmental impact in a module. Nevertheless, cost remains the major driver for innovation; top PV panels must combine cost/delay/yield to reach reasonable market share. Our paper presents the development of silicon heterojunction (SHJ) modules with exemplary power and reliability with significantly reduced environmental impact and components sourced from Europe. In order to guide the technology choice in the design phase, we performed a Life Cycle Assessment (LCA) sensitivity study. For a standard PV module, we identify the main steps to improve in order to reduce its environmental footprint. This guided us to tackle the components with the highest impact on the carbon footprint, namely the wafer, glass front sheet and aluminium frame. The proposed improvements will be tested from technical and economic point of view and assembled within one PV module. At the cell scale, we achieved the reduction of the carbon footprint by reducing the thickness of the wafers issued from the European value chain. Optimisation of metallisation and cell interconnection has limited the consumption of silver (Ag), a critical raw metal. At the module level, we implemented the reduction of glass thickness and the replacement of the aluminium frame with a natural fibre-based frame in a glass-backsheet module configuration. In addition, we applied a ‘design for recycling’ approach for the choice of encapsulant and backsheet. The combination of these innovations led us to the realisation of a 566-Wp recyclable module using a tiling interconnection, cells with an average efficiency of 22.57% with a carbon footprint of 313 kgCO<sub>2</sub>eq/kWp.</p>","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"33 1","pages":"184-199"},"PeriodicalIF":8.0,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3803","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gabriel Riedl, Philipp Haselsteiner, Gary Säckl, Gernot M. Wallner
{"title":"Environmental fatigue crack growth of PV glass/EVA laminates in the melting range","authors":"Gabriel Riedl, Philipp Haselsteiner, Gary Säckl, Gernot M. Wallner","doi":"10.1002/pip.3800","DOIUrl":"10.1002/pip.3800","url":null,"abstract":"<p>The delamination of encapsulants in photovoltaic (PV) modules is a common issue that leads to power loss due to optical losses. Encapsulant debonding is usually examined under monotonic loading conditions subsequent to environmental exposure such as damp heat. Service-relevant, superimposed environmental-mechanical fatigue loads are not considered adequately. Hence, the environmental fatigue delamination resistance of thermally toughened double glass laminates with an ethylene vinyl acetate copolymer (EVA) adhesive layer was investigated in this study. Focus was given to the melting range of EVA, in which the non-crosslinked crystalline phase fraction is already in the partly molten state. Double cantilever beam specimens were tested on an electrodynamic test machine at temperatures of 60, 70, 80, and 90°C and relative humidity (rh) levels of 2%, 30%, 50%, and 80%. The fractured surfaces were characterized by digital microscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and differential scanning calorimetry (DSC). The cyclic fatigue tests revealed a decay in delamination resistance at elevated temperature and humidity levels. At 70°C, the delamination resistance was low, regardless of the relative humidity. Most of the laminates failed by debonding. XPS analysis showed a reduction of the C=O and C–O content, along with an increase in Si–O content with increasing relative humidity. For laminates tested at 60 and 70°C, an EVA recrystallization peak was observed in DSC experiments. This peak was shifted to significantly higher temperatures at 80% rh. XPS and DSC indicated local hydrolysis within the porous fracture process zone ahead of the crack tip. Consequently, acetic acid formation led to a decrease in delamination resistance, resulting in lower fatigue threshold values. The investigations confirmed the significant impact of environmental conditions on the fatigue delamination resistance within glass/encapsulant laminates. Notably, acetic acid formation and a significant reduction in delamination properties were observed after around 100 h of environmental fatigue exposure.</p>","PeriodicalId":223,"journal":{"name":"Progress in Photovoltaics","volume":"32 9","pages":"623-635"},"PeriodicalIF":8.0,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3800","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}