Optics + Photonics for Sustainable Energy最新文献

{"title":"Investigation of a wedge adhesion test for edge seals","authors":"M. Kempe, J. Wohlgemuth, David C. Miller, Lori Postak, D. Booth, N. Phillips","doi":"10.1117/12.2239161","DOIUrl":"https://doi.org/10.1117/12.2239161","url":null,"abstract":"Many photovoltaic (PV) technologies have been found to be sensitive to moisture that diffuses into a PV package. Even with the use of impermeable frontsheets and backsheets, moisture can penetrate from the edges of a module. To limit this moisture ingress pathway from occurring, manufacturers often use a low permeability polyisobutylene (PIB) based edge seal filled with desiccant to further restrict moisture ingress. Moisture ingress studies have shown that these materials are capable of blocking moisture for the 25-year life of a module; but to do so, they must remain well-adhered and free of cracks. This work focuses on adapting the Boeing Wedge test for use with edge seals laminated using glass substrates as part of a strategy to assess the long-term durability of edge seals. The advantage of this method is that it duplicates the residual stresses and strains that a glass/glass module may have when the lamination process results in some residual glass bending that puts the perimeter in tension. Additionally, this method allows one to simultaneously expose the material to thermal stress, humidity, mechanical stress, and ultraviolet radiation. The disadvantage of this method generally is that we are limited by the fracture toughness of the glass substrates that the edge seal is adhered to. However, the low toughness of typical uncrosslinked or sparsely crosslinked PIB makes them suitable for this technique. We present data obtained during the development of the wedge test for use with PV edge seal materials. This includes development of the measuring techniques and evaluation of the test method with relevant materials. We find consistent data within a given experiment, along with the theoretical independence of fracture toughness measurements with wedge thickness. This indicates that the test methodology is reproducible. However, even though individual experimental sets are consistent, the reproducibility between experimental sets is poor. We believe this may be due to inconsistencies in sample history, sample batch, or small changes in sample preparation/assembly from one month to the next. Because the fracture strength of typical edge seal materials is so low, they cannot be relied upon for mechanical strength. A small stress or strain on the edge seal is capable of promoting delamination or tearing causing the edge seal to fail. Because of this, edge seals are very dependent on the processing and construction parameters in the full size PV module such that any long term evaluation of their durability must be conducted on full size modules to be accurate.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124895530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation between mechanical and chemical degradation after outdoor and accelerated laboratory aging for multilayer photovoltaic backsheets","authors":"Chiao-Chi Lin, Yadong Lyu, Li-Chieh Yu, X. Gu","doi":"10.1117/12.2238216","DOIUrl":"https://doi.org/10.1117/12.2238216","url":null,"abstract":"Channel cracking fragmentation testing and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy were utilized to study mechanical and chemical degradation of a multilayered backsheet after outdoor and accelerated laboratory aging. A model sample of commercial PPE backsheet, namely polyethylene terephthalate/polyethylene terephthalate/ethylene vinyl acetate (PET/PET/EVA) was investigated. Outdoor aging was performed in Gaithersburg, Maryland, USA for up to 510 days, and complementary accelerated laboratory aging was conducted on the NIST (National Institute of Standards and Technology) SPHERE (Simulated Photodegradation via High Energy Radiant Exposure). Fracture energy, mode I stress intensity factor and film strength were analyzed using an analytical model based on channel cracking fragmentation testing results. The correlation between mechanical and chemical degradation was discussed for both outdoor and accelerated laboratory aging. The results of this work provide preliminary understanding on failure mechanism of backsheets after weathering, laying the groundwork for linking outdoor and indoor accelerated laboratory testing for multilayer photovoltaic backsheets.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125536512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statistical overview of findings by IR-inspections of PV-plants","authors":"C. Buerhop, Tobias Pickel, H. Scheuerpflug, C. Camus, J. Hauch, C. Brabec","doi":"10.1117/12.2237821","DOIUrl":"https://doi.org/10.1117/12.2237821","url":null,"abstract":"First statistical evaluation of IR-inspections of PV-plants reveals that 86% of the installed PV-plants show IR-abnormalities. More than 120 PV-plants with more than 160,000 PV-modules were inspected and evaluated statistically. Main IR-abnormalities or failures in modules and string installations are analyzed, respectively. The average failure rate for PV-modules is about 8% and for module strings approximately 4%. The differentiation between the installation locations reveals that small residential installation show relatively more defective modules than large field installations. – Therefore, IR-imaging is a valuable method to give fast and reliable information about the actual quality and failure rate in inspected PV-installations.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122459684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How heat influences CIGSSe solar cells properties","authors":"M. Flammini, N. Debernardi, M. Le Ster, K. Bakker, B. Dunne, J. Bosman, M. Theelen","doi":"10.1117/12.2240266","DOIUrl":"https://doi.org/10.1117/12.2240266","url":null,"abstract":"Non-encapsulated CIGSSe solar cells, with a silver grid, were exposed to different temperatures for various periods in order to measure the effect of the heat exposure in CIGSSe modules. The heat treatment time and temperature were varied during the experiments, which were executed at atmospheric conditions. In all the cases, after reaching a temperature of about 300°C, the IV measurement showed a reduction of 2-3% in terms of VOC and JSC. This is confirmed respectively by Raman and EQE measurements as well. The efficiency drop was -7%, -29% and -48% respectively for 30 seconds, 300 seconds and 600 seconds of exposure time. With temperatures larger than 225°C, the series resistance starts to increase exponentially and a secondary barrier becomes visible in the IV curve. This barrier prevents the extraction of electrons and consequently reducing the solar cells efficiency. Lock-in thermography demonstrated the formation of shunts on the mechanical scribes only for 300 and 600 seconds exposure times. The shunt resistance reduction is in the range of 5% for all time periods.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134274941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modification of small noble metal particles on KCa2Nb3O10 restacked nanosheets and the photocatalytic activity","authors":"T. Oshima, K. Maeda","doi":"10.1117/12.2237467","DOIUrl":"https://doi.org/10.1117/12.2237467","url":null,"abstract":"A new method to modify KCa2Nb3O10 restacked nanohsheets with small Pt particle was developed, based on a simple electrostatic interaction between cationic precursor of Pt and negatively charged nanosheets. Compared to an ordinary impregnation method, the location of deposited Pt particles, size and valence state were different. More concretely, Pt was deposited not only on the external surface of the restacked KCa2Nb3O10 nanohsheets, but also in the interlayer nanospace. Moreover, the deposited Pt was mainly very small (≤ 1 nm) and electron-deficient. The Pt deposited restacked KCa2Nb3O10 nanosheets showed high photocatalytic activity for overall water splitting, which is the highest one among the nanosheets-based photocatalyst. The small particle size and deposition site of Pt are possible reasons for the high activity.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116162124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliability and efficacy of organic passivation for polycrystalline silicon solar cells at room temperature","authors":"O. Shinde, A. Funde, S. Jadkar, R. Dusane, N. Dhere, S. Ghaisas","doi":"10.1117/12.2237414","DOIUrl":"https://doi.org/10.1117/12.2237414","url":null,"abstract":"Oleylamine is used as a passivating layer instead of commercial high temperature SiNx. Oleylamine coating applied on the n-type emitter side with p-type base polycrystalline silicon solar cells at room temperature using a simple spin coating method. It has been observed that there is 16% increase in efficiency after Oleylamine coating. Further, the solar cell was subjected to standard characterization namely current-voltage measurement for electrical parameters and Fourier transform infrared spectroscopy to understand the interaction of emitter surface and passivating Oleylamine. However, the passivation layer is not stable due to the reaction between Oleylamine and ambient air content such as humidity and carbon dioxide. This degradation can be prevented with suitable overcoating.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122621956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of 1 MW PV array at the Kennedy Space Center","authors":"N. Dhere, E. Schneller, Wayne R. Martin, R. Dhere","doi":"10.1117/12.2237465","DOIUrl":"https://doi.org/10.1117/12.2237465","url":null,"abstract":"FP and L has deployed a 1 MW c-Si in a fenced compound at the Kennedy Space Center. Two 500 kW inverters located in an elevated and air-conditioned enclosure convert direct current (DC) to alternating current (AC). The generated power, DC and AC voltages and currents are measured and recorded. Charts of variation of PV parameters are generated for analyses. The generated power is also tabulated and reported on periodic basis. Infrared and visual images of the array, sections of the array, and of individual modules from the front and back are recorded periodically. Any interruption of power generation are recorded. The dust and corrosion on screws and frame were observed in a few modules. The temperature of active area of module is higher than that of metallic support and frame probably because of conduction of the heat by the heavy metallic structure. The 1-MW PV array is operating normally without signs of excessive degradation except for collection of dust towards the bottom of a few modules. Since these modules were not washed periodically and any cleaning was by rain. Thus the collection of dust towards the bottom of modules can be understood and does not pose a serious problem. Corrosion on screws and frame were observed in a few modules. This study if continued over a long time, will serve to follow the behavior of this reasonable size PV Plant.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114461106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing the weathering induced haze formation and gloss loss of poly(ethylene-terephthalate) via MaPd:RTS spectroscopy","authors":"Devin A. Gordon, A. Gok, C. W. Meyer, Cara L. Fagerholm, Noah W. Sweet, L. Denoyer, L. Bruckman, R. French","doi":"10.1117/12.2238295","DOIUrl":"https://doi.org/10.1117/12.2238295","url":null,"abstract":"Poly(ethylene-terephthalate) (PET) film is a widely used material in photovoltaic module backsheets, for its dielectric breakdown strength, and in optical displays for its excellent combination of properties, notably optical clarity. However, PET degrades and loses optical clarity under environmental stressors of heat, moisture, and ultraviolet irradiance. Stabilizers are often included in PET formulation to increase its longevity; however, even these are subject to degradation and further reduce optical clarity. In a previous study, it was found that material yellowing is dominant with UV light exposures while moisture mostly causes hazing of the samples. Lifetime service prediction models were developed for PET from yellowing and hazing responses. To study the loss of optical clarity in PET films, samples of a UV-stabilized grade of PET were exposed to heat, moisture, and UV irradiance as prescribed by ASTM-G154 Cycle 4 and their optical properties were studied over time. Surface gloss loss and bulk haze formation were observed as primary material responses to degradation; after the first 168 hour exposure step an initial three-fold increase in bulk haze and a two-fold reduction in gloss were observed. Multi-Angle, Polarization-Dependent, Reflection, Transmission, and Scattering (MaPd:RTS) spectroscopy was employed to fully characterize the haze formation and gloss loss of the PET films under exposure.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114730971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of twelve-month degradation in three polycrystalline photovoltaic modules","authors":"T. Lai, B. G. Potter, K. Simmons-Potter","doi":"10.1117/12.2237527","DOIUrl":"https://doi.org/10.1117/12.2237527","url":null,"abstract":"Polycrystalline silicon photovoltaic (PV) modules have the advantage of lower manufacturing cost as compared to their monocrystalline counterparts, but generally exhibit both lower initial module efficiencies and more significant early-stage efficiency degradation than do similar monocrystalline PV modules. For both technologies, noticeable deterioration in power conversion efficiency typically occurs over the first two years of usage. Estimating PV lifetime by examining the performance degradation behavior under given environmental conditions is, therefore, one of continual goals for experimental research and economic analysis. In the present work, accelerated lifecycle testing (ALT) on three polycrystalline PV technologies was performed in a full-scale, industrial-standard environmental chamber equipped with single-sun irradiance capability, providing an illumination uniformity of 98% over a 2 x 1.6m area. In order to investigate environmental aging effects, timedependent PV performance (I-V characteristic) was evaluated over a recurring, compressed day-night cycle, which simulated local daily solar insolation for the southwestern United States, followed by dark (night) periods. During a total test time of just under 4 months that corresponded to a year equivalent exposure on a fielded module, the temperature and humidity varied in ranges from 3°C to 40°C and 5% to 85% based on annual weather profiles for Tucson, AZ. Removing the temperature de-rating effect that was clearly seen in the data enabled the computation of normalized efficiency degradation with time and environmental exposure. Results confirm the impact of environmental conditions on the module long-term performance. Overall, more than 2% efficiency degradation in the first year of usage was observed for all thee polycrystalline Si solar modules. The average 5-year degradation of each PV technology was estimated based on their determined degradation rates.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127861108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solar hydrogen production on some water splitting photocatalysts","authors":"T. Takata, T. Hisatomi, K. Domen","doi":"10.1117/12.2236434","DOIUrl":"https://doi.org/10.1117/12.2236434","url":null,"abstract":"Photocatalytic overall water splitting into H2 and O2 is expected to be a promising method for the efficient utilization of solar energy. The design of optimal photocatalyst structures is a key to efficient overall water splitting, and the development of photocatalysts which can efficiently convert large portion of visible light spectrum has been required. Recently, a series of complex perovskite type transition metal oxynitrides, LaMgxT 1-xO1+3xN2-3x, was developed as photocatalysts for direct water splitting operable at wide wavelength of visible light. In addition two-step excitation water splitting via a novel photocatalytic device termed as photocatalyst sheet was developed. This consists of two types of semiconductors (hydrogen evolution photocatalyst and oxygen evolution photocatalyst) particles embedded in a conductive layer, and showed high efficiency for overall water splitting. These recent advances in photocatalytic water splitting were introduced.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127392204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}