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Photovoltaics are used for the direct conversion of sunlight into electricity. In order to provide useful power, the individual solar cells must be connected together. This electrically connected and environmentally protected unit is termed a photovoltaic (PV) module. The structure of a PV module consists of a number of layers of various materials...
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![Figure 1. Methods for measuring the biodegradability of starch [13].](profile/Marita-Piglowska/publication/339080424/figure/fig1/AS:855671645958145@1581019426288/Methods-for-measuring-the-biodegradability-of-starch-13_Q320.jpg)
![Figure 3. Possible pathways during starch degradation [17].](profile/Marita-Piglowska/publication/339080424/figure/fig2/AS:855671645933568@1581019426334/Possible-pathways-during-starch-degradation-17_Q320.jpg)
The main aim of this study is to estimate the kinetic and thermodynamic parameters of thermal decomposition of starches by the Coats-Redfern method. This procedure is a commonly used thermogravimetric analysis/difference thermal gravimetry/differental thermal analysis (TG/DTG-DTA) kinetic method for single rate form. The study also shows a proposed...
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... One of the challenges in maintaining the efficiency of the whole PV system is the material degradation as a result of exposure to harsh environmental conditions [171], [172] which leads to system degradation and efficiency drop. The main environmental factors affecting a PV system are i) temperature, ii) dust accumulated on solar cells, ii) humidity, and iv) Ultraviolet (UV). ...
The growing population, demand for healthy diets, and shift towards plant-based protein diets are increasing pressure on food production and land use. However, current agricultural practices jeopardize soil health and biodiversity, which threatens future ecosystems and food production. Precision Agriculture (PA) offers a solution to these challenges by minimizing resource use and maximizing yield through a multidisciplinary approach that includes engineering, AI, and robotics. Robotics, in particular, will be critical to delivering PA and enabling sustainable, healthy food production.
This book chapter discusses robotic technologies available for precision agriculture.
For precision agriculture to be truly sustainable, agriculture machinery and devices used for data collection must operate on clean energy. Among renewable energy sources, solar energy and solar PV show great potential to dominate the future of sustainable agriculture development. Solar-powered devices are inevitable for developing PV in rural and off-grid agriculture farms and lands. To transition to photovoltaic agriculture, significant changes to agricultural practices and the adoption of smart technologies like IoT, robotics, and WSN are necessary.
As future food production adapts to changing consumer behaviour and environmental factors, PA will play a critical role in improving sustainability by minimizing the use of diminishing resources and GHG emissions through the use of renewable energy sources. However, the adoption of new technologies should also incorporate green energy sources like solar energy to meet power requirements for the sustainable development of these smart technologies. With the influx of robotic technologies into the agriculture sector, increasing power demand is inevitable, especially in remote areas where PV-based systems can play a game-changing role. The agricultural sector is expected to witness a technological revolution towards sustainable food production, which cannot be achieved without solar PV development and support.
... This history and growing concern over land use highlight the challenge of meeting the soaring demands for solar power while protecting rural and agricultural lands [166]. One of the challenges in maintaining the efficiency of the whole PV system is the material degradation as a result of exposure to harsh environmental conditions [167,168] which leads to system degradation and efficiency drop. ...
The energy transition is one of the greatest challenges of our time. While photovoltaics (PVs) became the cheapest technology for generating electricity in many regions, the rising development of ground-mounted PV requires large areas and, hence, competes with other land use forms such as agriculture. Agrivoltaics enables dual use of land for both agriculture and PV power generation considerably increasing land-use efficiency, allowing for an expansion of PV capacity on agricultural land while maintaining farming activities. In recent years, agrivoltaics has experienced a dynamic development mainly driven by Japan, China, France, and Germany. In this chapter, we provide an overview of the current state of agrivoltaics starting with a definition and classification of typical systems. Section 5.2 sheds light on basic agricultural implications in agrivoltaic systems such as light availability, further microclimatic impacts, and crop selection. In Section 5.3, we address typical technical structures and agricultural applications distinguishing between interspace PV and overhead PV systems. Section 5.4 outlines relevant characteristics of PV modules used for agrivoltaics including standard crystalline silicon and thin-film cell technologies as well as emerging module technologies. Section 5.5 provides an economic analysis of agrivoltaic systems based on a location in southern Germany and Section 5.6 summarizes the most relevant facts about the preliminary German standard DIN SPEC 91434 published in April 2021. In Section 5.7, we present the results of a case study on societal implications conducted in southern Germany within the research project APV-RESOLA. Section 5.8 provides brief country profiles of the existing policies around the world while Section 5.9 concludes and outlines perspectives of agrivoltaics.
... This history and growing concern over land use highlight the challenge of meeting the soaring demands for solar power while protecting rural and agricultural lands [166]. One of the challenges in maintaining the efficiency of the whole PV system is the material degradation as a result of exposure to harsh environmental conditions [167,168] which leads to system degradation and efficiency drop. ...
As a part of the global clean energy transition, the increased deployment of ground-mounted PV systems depends on the availability of land. In some regions, scarce land resources can lead to competition between agriculture and PV land use, threatening both food and energy security. Agrivoltaics is a method to combine agricultural and electricity production on the same unit of land, which significantly increases land-use efficiency and has the potential to contribute towards mitigation of related land-use conflicts. Additionally, agrivoltaics is expected to stabilize agricultural yields in regions that are vulnerable to the effects of climate change by providing weather protection and shading and might contribute to strengthen and vitalize rural economies and livelihoods.
Adolf Goetzberger and his colleague Armin Zastrow were the first to propose the concept of agrivoltaics in the early 1980s. However, it was only about 10 years ago that agrivoltaics gained traction. In Japan, pioneer Akira Nagashima analyzed crop growth below PV modules within the first research pilot systems in 2004 and promoted the technology under the heading of “solar sharing” which led to the first governmental support scheme implemented in 2012. In 2014, China installed the first large-scale agrivoltaic systems and, still, today remains the country with the largest installed capacity in the world. France was the first European country to systematically support agrivoltaics with regular tenders starting in 2017. This development was largely driven by the research of Christian Dupraz at the French Institut National de la Recherche Agronomique and the Sun’Agri R&D program. Other countries that implemented or plan to implement governmental supporting schemes are the United States of America in the state of Massachusetts, South Korea, India, Israel, Germany, and Italy. An overview of the policies of those countries can be found in Section 5.7.
In 2021, agrivoltaics emerged as a market-ready technology with a globally installed capacity of more than 14 GWp. In most subtropical and semiarid regions, however, agrivoltaics remains widely unknown even though the technical potential appears to be very high especially in these regions.
... Vinyl acetate groups, which are esters, are known to be very sensitive to various environmental factors such as temperature, ultraviolet (UV) radiation, or oxygen. They can easily decompose to generate free radicals, which can then form different carboxylic acids [42,43]. In the present case, FTIR analyses confirm that the thermal degradation of ester groups occurred for samples immersed in the alkaline solution at 40 and 60 • C. ...
... Vinyl acetate groups, which are esters, are known to be very sensitive to various environmental factors such as temperature, ultraviolet (UV) radiation, or oxygen. They can easily decompose to generate free radicals, which can then form different carboxylic acids [42,43]. In the present case, FTIR analyses confirm that the thermal degradation of ester groups occurred for samples immersed in the alkaline solution at 40 and 60 °C. ...
... -An enthalpic jump is visible around −30 • C, which can be attributed to the glass transition of the amorphous phase of the EVA copolymer; -A large endothermic region is observed between −30 and 110 • C, from which three distinct peaks emerge at approximately 40, 50 and 90 • C. This domain corresponds to the melting temperature range generally reported for the crystalline phase of EVAs [42,43,46]. The presence of multiple peaks reveals the existence of several populations and sizes of crystalline lamellae. ...
The present study investigates the environmental durability of a distributed optical fiber sensing (DOFS) cable on the market, commonly used for distributed strain measurements in reinforced concrete structures. An extensive experimental program was conducted on different types of specimens (including samples of bare DOFS cable and plain concrete specimens instrumented with this DOFS cable) that were exposed to accelerated and natural ageing (NA) conditions for different periods of up to 18 months. The instrumentation of both concrete specimens consisted of DOFS cables embedded at the center of the specimens and bonded at the concrete surface, as these two configurations are commonly deployed in the field. In these configurations, the alkalinity of the surrounding cement medium and the outdoor conditions are the main factors potentially affecting the characteristics of the DOFS component materials and the integrity of the various interfaces, and hence impacting the strain transfer process between the host structure and the core optical fiber (OF). Therefore, immersion in an alkaline solution at an elevated temperature or freeze/thaw (F/T) and immersion/drying (I/D) cycles were chosen as accelerated ageing conditions, depending on the considered configuration. Mechanical characterizations by tensile and pull-out tests were then carried out on the exposed specimens to assess the evolution of the mechanical properties of individual component materials as well as the evolution of bond properties at various interfaces (internal interfaces of the DOFS cable, and interface between the cable and the host structure) during ageing. Complementary physico-chemical characterizations were also performed to better understand the underlying degradation processes. The experimental results highlight that immersion in the alkaline solution induced a significant and rapid decrease in the bond properties at internal interfaces of the DOFS cable and at the cable/concrete interface (in the case of the embedded cable configuration), which was assigned to chemical degradation at the surface of the cable coating in contact with the solution (hydrolysis and thermal degradation of the EVA copolymer component). Meanwhile, F/T and I/D cycles showed more limited effects on the mechanical properties of the component materials and interfaces in the case of the bonded cable configuration. A comparison with the same specimens exposed to outdoor NA suggested that the chosen accelerated ageing conditions may not be totally representative of actual service conditions, but provided indications for improving the ageing protocols in future research. In the last part, an analysis of the distributed strain profiles collected during pull-out tests on instrumented concrete specimens clearly illustrated the consequences of ageing processes on the strain response of the DOFS cable.
... Les groupes acétates de vinyle, qui sont des esters, sont connus pour être particulièrement sensibles à différents facteurs environnementaux comme la température, le rayonnement UV ou l'oxygène. Ils peuvent facilement se décomposer pour générer des radicaux libres, qui vont ensuite pouvoir former différents acides carboxyliques [158] [159]. Les analyses IRTF confirment donc qu'une dégradation thermique de ces esters a bien eu lieu dans la solution alcaline à 40 et 60 °C. ...
... Les thermogrammes ont ensuite permis de déterminer la Tg de la phase amorphe ainsi que le taux de cristallinité pour l'ensemble des échantillons (à l'état initial T0, et à T4 après 12 mois de vieillissement). Le taux de cristallinité est évalué selon l'expression suivante [158] [167] : ...
La surveillance des structures de génie civil constitue un enjeu majeur et fait encore l’objet de nombreuses recherches. En particulier, les problématiques de coût, de durabilité des capteurs et de fiabilité des mesures restent des aspects fondamentaux à prendre en compte pour toute nouvelle solution d’instrumentation. Les capteurs à fibre optique (FO) rencontrent un intérêt croissant pour l’acquisition de mesures réparties de déformation/température dans les ouvrages en béton armé et pour le monitoring de structures en général, en raison des avantages offerts en termes de précision, de déport de la mesure sur de longues distances et d’une faible intrusivité par rapport aux capteurs traditionnels. Dans ces applications, des câbles à FO sont généralement collés en parement ou noyés à l’intérieur de la structure en béton. Selon la configuration, ils sont alors exposés aux conditions climatiques ou soumis à l’environnement alcalin de la matrice cimentaire, et leurs caractéristiques physiques/mécaniques peuvent alors évoluer dans le temps sous l’effet des vieillissements. La durabilité des capteurs et la fiabilité des mesures sur le long terme restent encore mal connues dans ces environnements de service complexes, et sont également peu documentées par les fabricants ou dans la littérature. Le travail mené dans cette thèse vise donc à mieux appréhender ces problématiques à travers une vaste étude expérimentale de durabilité en laboratoire, complétée par une étude de terrain sur des corps d’épreuves massifs instrumentés par capteurs à FO.Le premier volet de la thèse propose un programme expérimental complet portant sur des éprouvettes de béton instrumentées par deux câbles à FO du commerce, qui sont exposées à des vieillissements accélérés représentatifs des applications considérées et à un vieillissement naturel sur site extérieur. Des caractérisations mécaniques, physico-chimiques et géométriques de ces échantillons sont alors réalisées à différentes échéances de temps au cours des vieillissements et permettent d’évaluer la durabilité de ces deux câbles à FO pour les deux configurations d’instrumentation possibles (câbles noyés / collés en parement). L’évolution du transfert d’effort du béton vers le cœur de la FO est ensuite évaluée numériquement en intégrant les résultats expérimentaux dans un modèle aux éléments finis simplifié. En parallèle de cette étude de laboratoire, plusieurs blocs de béton du projet ODOBA de l’IRSN, destinés à subir des cycles de vieillissement accéléré pour déclencher les pathologies de gonflement du béton, ont été instrumentés au moyen de câbles à FO noyés et collés en parement. Ce second volet de la thèse vise à démontrer l’aptitude de cette technologie pour la détection et le suivi à long terme des pathologies de gonflement potentiellement rencontrées sur les enceintes de centrales nucléaires (réaction sulfatique interne : RSI, réaction alcali-granulat : RAG et couplage RAG/RSI). Les résultats obtenus contribueront à établir des critères objectifs permettant de choisir l’instrumentation des structures de centrales nucléaires ainsi que des méthodes facilitant l’interprétation des mesures sur le long terme
Extending photovoltaic (PV) module lifetimes beyond 30 years is a goal of significant priority. A challenge that must first be addressed, however, is the development of a predictive reliability model that captures the synergy of terrestrial stressors on module degradation, particularly at encapsulant interfaces. Using a metrology designed specifically for PV modules, a comprehensive study of the widely used ethylene vinyl acetate encapsulant was performed in which encapsulant adhesion was evaluated as a function of environmental stressors (UV exposure, temperature, and humidity) for modules aged both under accelerated lab and internationally located field conditions for months to nearly 3 decades. Mechanical and chemical characterization methods are combined with fundamental polymer reaction engineering to unravel the degradation processes active at the molecular scale that lead to encapsulant delamination. An analytical and modular model framework is put forward enabling the prediction of long‐term PV module durability, starting from fundamental principles at the molecular level and explicitly accounting for bond rupture events in the bulk encapsulant and at the encapsulant interfaces. Successful parameter tuning to adhesion data indicates a dominant occurrence of deacetylation, β‐scission, and hydrolytic depolymerization, respectively. The model contributes to the longstanding challenge of predicting module lifetimes in any geographic location while minimizing time‐consuming and costly aging studies.
Delamination of encapsulant materials from PV cell surfaces often appears to originate at regions with metallization. Using a fracture mechanics based metrology, the adhesion of ethylene vinyl acetate (EVA) encapsulant to screen-printed silver metallization was evaluated. At room temperature, the fracture energy Gc [J/m
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>
] of the EVA/silver interface (952 J/m
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>
) was ~70% lower than that of the EVA/antireflective (AR) coating (>2900 J/m
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>
) and ~60% lower than that of the EVA to the surface of cell (2265 J/m
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>
). After only 300 h of damp heat aging, the adhesion energy of the silver interface dropped to and plateaued at ~50-60 J/m
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>
while that of the EVA/AR coating and EVA/cell remained mostly unchanged. Elemental surface analysis showed that the EVA separates from the silver in a purely adhesive manner, indicating that bonds at the interface were likely displaced in the presence of humidity and chemical byproducts at elevated temperature, which in part accounts for the propensity of metalized surfaces to delaminate in the field.
