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8th World Conference on Photovoltaic Energy Conversion; 678-681, Current more novel interconnection methods for Si solar cells such as shingling, multi-wire, conductive backsheet, and multi-ribbon approaches, are structurally more complex than conventional 2-5 busbar stringing. The most common techniques used for the development of these concepts are electrical characterization (current-voltage measurements and electroluminescence imaging) in combination with a cross-section analysis using SEM and EDX. Other characterization methods, such as scanning acoustic microscopy (SAM) are implemented, especially to search for voids and delamination within the module. Using micro-computed tomography (μCT) is reported as a viable method to inspect new module concepts in the past, however, very few effective results are published. Current state-of-the-art μCT devices are capable to achieve a lower voxel size and higher resolution on larger samples than ever before. In this work, the multi-ribbon interconnection for back-contact cells under development at imec is being used as a case study to investigate the potential of these new μCT devices for PV research. A 20 x 20 cm2 one-cell module is electrically characterized before, during and after reliability tests in the form of thermal cycling and humidity-freeze cycling. The results show an unstable shunt being present in the module. Before and after the reliability tests, a TESCAN UniTOM XL scanner is used to scan the one-cell module using μCT. Due to a large amount of metal in the module, artifacts such as photon scattering and shadowing in the region around the ribbons were observed. The use of binning and different metal filters was tested as a way to decrease these artifacts. Using a 1 mm tin filter in combination with binning seems to achieve the best results when scanning (part of) a PV module.

38th European Photovoltaic Solar Energy Conference and Exhibition; 24-27, In this work we report on our approach on integrating c-Si PV into lightweight structures, in particular towards vehicle integration. To this end we want to get rid of the (bulk weight of the) glass but seek a suitable replacement in terms of mechanical stability. First we elaborate on the most basic standards and norms that VIPV products should relate to in terms of (thermo-)mechanical testing. Then, for the experimental part, 2 concepts are investigated. In a first approach, we reinforced the encapsulant with glass fibre material, while in a second one we applied a dedicated glass-fibre-reinforced sheet as a replacement of the backsheet. In both cases we stay as close as possible to using commercially available material. Extending our previously reported work, we then elaborate for each approach the testing that has been carried out so far, and what is still ongoing and being planned in the short-term future (before the conference): indicating the promising results so far on thermal cycling and vibration testing, the hail impact testing is a challenge to be tackled still

38th European Photovoltaic Solar Energy Conference and Exhibition; 728-731, Back-contact solar cells are gaining terrain in the PV industry, although the lack of a standardized and low-cost interconnection method inhibits their market growth. To overcome this challenge, the three-dimensional multi-ribbon interconnection is proposed by imec as a novel interconnection concept for highly efficient back-contact cells. It is based on an interconnection fabric of encapsulant with incorporated metal ribbons that form a three-dimensional network. Module fabrication consists of a layup phase and a lamination step. In the layup step, a stack is established with the frontsheet, a front encapsulant, the cells, the interconnection fabric a glass or polymer backsheet. During the lamination step, soldering and encapsulation happen simultaneously. In previous research, the concept was tested in two four-cell modules with interdigitated back-contact (IBC) cells, both passing three times the IEC 61215 standard for thermal cycling reliability testing. In this work, these modules were tested using damp-heat and humidity-freeze tests. No significant sign of degradation was observed based on electrical characterization and electroluminescence imaging after consecutive 1000 hours of damp-heat and 50 cycles of humidity-freeze exposure.

37th European Photovoltaic Solar Energy Conference and Exhibition; 33-37, In this work, we present our progress on the multi-wire interconnection approach that we are developing, based on a contact sheet that integrates the interconnect wiring into the encapsulant. After a brief motivation and explanation of the concept, the latest results are indicated in terms of manufacturing of the contact sheets via 2 routes, and the potential in varying encapsulant formulation, wire diameter and solder coating thickness. After this, we discuss also our efforts in upscaling and automation of the technology, as well as the reliability testing and the application of the technology towards a BIPV environment.

35th European Photovoltaic Solar Energy Conference and Exhibition; 71-74, In previous contributions, we presented already several multi-wire interconnection approaches, both for back-contact [1,2] and 2-side contacted cells [3]. In this paper we want to report our progress in further investigating and developing the latter approach. We introduce our methodology to allow mapping of individual solder joint quality (that can be extended quantitatively) on commercially available solar cells. Applying the technology on 1-cell samples, we compare different encapsulants, lamination times and stitch patterns, and demonstrate a 2x2-cell module. We subject the fabricated samples to thermal cycling to get preliminary feedback on their performance reliability-wise, and to improve our understanding of the underlying mechanisms. Finally, we made a 9-cell module with busbarless cells and adapted metallization design, to show the full module-level interconnection potential of this technology.

35th European Photovoltaic Solar Energy Conference and Exhibition; 1328-1332, Multi-wire designs for photovoltaic modules already proved its advantages in the past. In previous contributions, several multi-wire interconnection approaches were presented, both for back-contact [4] and 2-side contacted cells [4,5]. This paper reports the progress in the woven multi-wire interconnection which enables a combined lamination and soldering process using low-temperature melting point solder alloys. This work focuses on the solder joint formation and aims to correlate the viscoelastic properties of the encapsulant material during lamination with the electrical and visual characterisation of the solder joint. To do so, three analysis techniques are used: electroluminescence (EL) imaging, current-voltage (IV) measurements and a cross-section analysis. The aim is to optimize the lamination process and material selection for optimal solder joint formation. Rheological measurements on the encapsulation polymers revealed the viscosities at various temperatures. Small modules were fabricated and tested. According to the results of these tests, the optimal lamination temperature is around 165 ºC and at which the viscosity of the encapsulant should be at least 7500 Pa∙s. One of the tested encapsulant materials met these requirements and had the best electrical properties according to the EL-imaging and IV-measurements.

In het recent verschenen rapport over de bekostiging van de curatieve ggz concludeert de Algemene Rekenkamer (2017): ‘informatie die met ROM [routine outcome monitoring] wordt verkregen, heeft beperkingen en is van onvoldoende kwaliteit om te dienen als sturingsinformatie bij de zorginkoop’ (p. 14). Dit rapport is door een groep psychiaters en psychologen aangegrepen om de petitie ‘Stop benchmark met ROM’ (www.stoprom.com) in het leven te roepen, die inmiddels door ruim 6000 mensen getekend is. In dit artikel reageren wij op deze petitie. Wij onderschrijven dat ROM geen basis mag zijn voor zorginkoop, maar vinden dat ROM en benchmarking van grote waarde kunnen zijn voor het verbeteren van de kwaliteit van de behandeling en pleiten daarom voor inhoudelijke doorontwikkeling van benchmarking in plaats van deze te stoppen.

Background Recent evidence supports that most non-lacunar cryptogenic strokes are embolic. Accordingly, these strokes have been designated as embolic strokes of undetermined source (ESUS). Aims We undertook an international survey to characterize the frequency and clinical features of ESUS patients across global regions. Methods Consecutive patients hospitalized for ischemic stroke were retrospectively surveyed from 19 stroke research centers in 19 different countries to collect patients meeting criteria for ESUS. Results Of 2144 patients with recent ischemic stroke, 351 (16%, 95% CI 15% to 18%) met ESUS criteria, similar across global regions (range 16% to 21%), and an additional 308 (14%) patients had incomplete evaluation required for ESUS diagnosis. The mean age of ESUS patients (62 years; SD = 15) was significantly lower than the 1793 non-ESUS ischemic stroke patients (68 years, p ≤ 0.001). Excluding patients with atrial fibrillation ( n = 590, mean age = 75 years), the mean age of the remaining 1203 non-ESUS ischemic stroke patients was 64 years ( p = 0.02 vs. ESUS patients). Among ESUS patients, hypertension, diabetes, and prior stroke were present in 64%, 25%, and 17%, respectively. Median NIHSS score was 4 (interquartile range 2–8). At discharge, 90% of ESUS patients received antiplatelet therapy and 7% received anticoagulation. Conclusions This cross-sectional global sample of patients with recent ischemic stroke shows that one-sixth met criteria for ESUS, with additional ESUS patients likely among those with incomplete diagnostic investigation. ESUS patients were relatively young with mild strokes. Antiplatelet therapy was the standard antithrombotic therapy for secondary stroke prevention in all global regions.

Background and Purpose— Atrial fibrillation (AF) is increasingly recognized as the single most important cause of disabling ischemic stroke in the elderly. We undertook an international survey to characterize the frequency of AF-associated stroke, methods of AF detection, and patient features. Methods— Consecutive patients hospitalized for ischemic stroke in 2013 to 2014 were surveyed from 19 stroke research centers in 19 different countries. Data were analyzed by global regions and World Bank income levels. Results— Of 2144 patients with ischemic stroke, 590 (28%; 95% confidence interval, 25.6–29.5) had AF-associated stroke, with highest frequencies in North America (35%) and Europe (33%) and lowest in Latin America (17%). Most had a history of AF before stroke (15%) or newly detected AF on electrocardiography (10%); only 2% of patients with ischemic stroke had unsuspected AF detected by poststroke cardiac rhythm monitoring. The mean age and 30-day mortality rate of patients with AF-associated stroke (75 years; SD, 11.5 years; 10%; 95% confidence interval, 7.6–12.6, respectively) were substantially higher than those of patients without AF (64 years; SD, 15.58 years; 4%; 95% confidence interval, 3.3–5.4; P75 years old) and more often women.