The total light transmittance of hand lay-up glass fiber-reinforced polymer laminates for building construction was investigated with a view to two architectural applications: translucent load-bearing structures and the encapsulation of photovoltaic cells into glass fiber-reinforced polymer building skins of sandwich structures. Spectrophotometric experiments on unidirectional and cross-ply glass fiber-reinforced polymer specimens in the range from 0.20 to 0.45 fiber volume fraction and artificial sunlight exposure experiments on encapsulated amorphous silicon photovoltaic cells were performed. Analytical models have been developed to predict light transmittance through glass fiber-reinforced polymer structures and the percentage of solar radiation reaching encapsulated photovoltaic cells. The total amount of fibers in the laminates was the major parameter influencing light transmittance, with fiber architecture having little effect and regardless of fiber volume fraction. Eight-three percent of solar irradiance in the band of 300-800nm reached the surface of amorphous silicon photovoltaic cells encapsulated below structural glass fiber-reinforced polymer laminates with a fiber reinforcement weight of 820g/m(2), demonstrating the feasibility of conceiving multifunctional glass fiber-reinforced polymer structures.
#1André Kostro(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 6
#2Mario Geiger(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 17
Last. Andreas Schüler(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 20
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A novel concept for an advanced fenestration system was studied and samples were produced to demonstrate the feasibility. The resulting novel glazing will combine the functions of daylighting, glare protection, and seasonal thermal control. Coated microstructures provide redirection of the incident solar radiation, thus simultaneously reducing glare and projecting daylight deep into the room in the same manner as an anidolic mirror-based system.The solar gains are reduced for chosen angles corre...
External quantum efficiency (EQE) of a solar cell provides information on the internal operations of the solar cells which can be used in optimization of solar cell design. The EQE of solar cells for space applications is adversely affected by the influence of charged particles in space. Usually numerical model based software, e.g., PC1D, are used to estimate the EQE and fitted with the measured EQE to obtain degradation performance of space solar cells. However, the accuracy of these models may...
Photovoltaic electricity has already proven its ability to compete with other well established technologies for energy production. The abundant and non-toxic raw materials, the yearly increasing efficiency as well as the production cost of silicon thin-film solar cells getting lower and lower make this technology always more interesting for a wide spread use. Beside the functional features, the size, colour and glass texture of a PV module determine its appearance and aesthetics. In order to be ...
Last. Behzad D. Manshadi(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 7
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The feasibility of encapsulating solar cells into the glass fiber-reinforced polymer (GFRP) skins of load-bearing and thermally insulating sandwich elements with foam cores has been evaluated. Exposure of the encapsulated cells to artificial sunlight led to a significant temperature increase on the top sandwich surface, which almost reached the glass transition temperature of the resin. Mechanical loading up to serviceability limit loads did not cause any damage to the solar cells. Stresses of l...
Increasing the amount of light that reaches the cell is one approach to improved photovoltaic (PV) module efficiency. In current designs using weathering layers of glass or poly(co- ethylene-tetrafluoroethylene) (Teflon® ETFE), some light is lost due to reflection and scattering due to haze. Teflon® FEP, poly(co- tetrafluoroethylene-hexafluoropropylene), offers both a lower index of refraction and higher transparency than existing front sheet materials for modules, leading to improved efficiency...
#1K. Jason Maung(UCLA: University of California, Los Angeles)H-Index: 1
#2H. Thomas Hahn(UCLA: University of California, Los Angeles)H-Index: 1
Last. Y.S. Ju(UCLA: University of California, Los Angeles)H-Index: 1
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Multifunction integration of solar cells in load-bearing structures can enhance overall system performance by reducing parasitic components and material redundancy. The article describes a manufacturing strategy, named the co-curing scheme, to integrate thin-film silicon solar cells on carbon-fiber-reinforced epoxy composites and eliminate parasitic packaging layers. In this scheme, an assembly of a solar cell and a prepreg is cured to form a multifunctional composite in one processing step. The...
Abstract The term “self-sensing composites” is sometimes used to describe the case where the reinforcing glass fibres in advanced fibre-reinforced composites are used as the sensors for chemical process-monitoring (cure monitoring). This paper presents conclusive evidence to demonstrate that reinforcing E-glass fibres can be used for in situ cure monitoring. The cure behaviour of an epoxy/amine resin system was compared using evanescent wave spectroscopy via the reinforcing E-glass fibres and co...
Foreword. Preface. Contributors. Acknowledgments. Chapter 1 The Integrated Building Design Process. Chapter 2 A History of the Environmental Movements. Chapter 3 Modern International Conferences and Treaties. Chapter 4 The Emergence of Green Building and Green Building Legislation. Chapter 5 Sources of Chemicals in the Environment. Chapter 6 Environmental Chemicals in Humans and Buildings. Chapter 7 Indoor Air Quality Technologies-Green Design for Long-Term Occupant Health. Chapter 8 Indoor Envi...
Indium tin oxide (ITO) thin films were prepared by RF sputtering of ceramic ITO target in pure argon atmosphere at a high base pressure of 3x10^-^4mbar without substrate heating and oxygen admittance. The use of pure argon during deposition resulted in films with high transparency (80-85%) in the visible and IR wavelength region. The films were subsequently annealed in air in the temperature range 100-400^oC. The annealed films show decreased transmittance in the IR region and decreased resistiv...
The increasing share of various thin film technologies on the global PV market has intensified the discussion if there is a best technology for a specific application and location to achieve a maximum annual energy yield. A key point for comparison of energy yields for different technologies is the determination of the installed power, which is not a trivial task for thin film technologies. In addition, reversible changes of the output power (annealing, light soaking) and a possible long term va...
Building integrated photovoltaic (BIPV) technologies are promising and practical for sustainable energy harvesting in buildings. BIPV products are commercially available, but their electrical power outputs in practice are negatively affected by several factors in outdoor environments. Performance improvement of BIPV applications requires mitigation approaches based on an understanding of these factors. A review was, therefore, conducted on this issue in order to providing guidance for practical ...
This paper presents a thermal investigation of lightweight on-board receiver modules of wireless power transfer systems for electric vehicles. The studied modules are capable of receiving up to 11 kW at a resonance frequency of 85 kHz over a distance of 110–160 mm. The receiver modules were built as sandwich and space–frame concept to design stiff and lightweight structures. The high transmission power of automotive wireless power transfer systems combined with the multi-part assembly of receive...
Last. Thomas Keller(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 45
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Abstract Structural loads, especially in-plane compression, may cause local buckling and debonding of the photovoltaic (PV) cells that are mechanically integrated with structural members and this may lead to degradation in their electrical performance. This paper proposes an approach to mitigate the strains transferred from structural members to PV cells through the partial composite action provided by low-modulus adhesives. Specimens were fabricated by bonding amorphous silicon (a-Si) PV cells ...
#1Qiuxia Wang(HIT: Harbin Institute of Technology)H-Index: 2
#2Fuchen Zhang(HIT: Harbin Institute of Technology)H-Index: 3
Last. Yongping Bai(HIT: Harbin Institute of Technology)H-Index: 21
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In this study, the preparation and properties of poly(ethylene terephthalate-co-2-methyl-1,3-propanediol) copolyester (PEMT) were reported. The PEMT crystallization properties, optical properties, thermal properties, rheological properties, and other properties were characterized by nuclear magnetic resonance (1H NMR), differential scanning calorimetry, thermo gravimetric analysis, ultraviolet visible near-infrared (UV-VIS-NIR) spectroscopy, polarizing microscope crystal culture, X-ray diffracti...
Last. Chao Zhang(NPU: Northwestern Polytechnical University)H-Index: 123
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Abstract Clean, plentiful, and easy-to-harvest solar energy is the ultimate renewable energy. It is becoming more important as the world begins to take notice of the burgeoning carbon emission problems that come with burning fossil fuels. Thin-film solar cells have been increasingly used for energy harvesting. This paper studies the effect of mechanical deformation on the performances of amorphous silicon (a-Si) and perovskite solar cells. Compression and tension tests were conducted on a-Si sol...
This article describes the implementation of plant-derived isosorbide (IS) and isomannide (IM) in the copolymerization modification of poly(ethylene terephthalate). The effects of the two comonomers on the optical, crystallization, and thermal properties of the resulting copolyesters were studied using the following analytical methods: proton nuclear magnetic resonance; differential scanning calorimetry; X-ray diffraction; thermogravimetry; and ultraviolet-visible spectroscopy. As comonomers, IS...
#1Shun Xu(MOE: Chinese Ministry of Education)H-Index: 3
#2Longhai Li(NUAA: Nanjing University of Aeronautics and Astronautics)H-Index: 3
Last. Mo Li(MOE: Chinese Ministry of Education)H-Index: 1
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: To improve the torsional resistance capability of multilayered composite pipes, a bionic design was presented based on the rostrum of Cyrtotrachelus Bugueti Guer. Morphology and mechanical properties of the weevil's rostrum were studied. Scanning electron microscope (SEM) was employed to observe the macro-/microstructure and inner structure. Nanoindentation was carried out to measure the elastic modulus and the hardness of the biological materials. Based on the structure of rostrum, a mathemat...
#1Carlos Pascual(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 2
#2Julia de Castro(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 15
Last. Thomas Keller(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 45
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The encapsulation of dye solar cells in translucent, structural and lightweight glass fiber-reinforced polymer laminates was investigated with a view to designing multifunctional envelopes for daylit buildings. Small and large integrating sphere experiments and solar radiation experiments were performed to determine the light transmittance of the laminates and the electrical efficiency of the encapsulated cells. An overall cell efficiency of 3.9% (before encapsulation) only decreased to 3.4% aft...
#1André Kostro(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 6
#2Mario Geiger(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 17
Last. Andreas Schüler(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 20
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Advanced optical ray tracing software, CFSpro, was developed for the study and optimization of complex fenestration systems (CFSs). Using an algorithm mixing 2D and 3D approaches, accurate computation of large numbers of rays in extruded geometries can be performed and visualized in real time. A thin film model was included to assess the spectral control provided by coatings. In this paper, the ray tracing model is described and validated. A novel glazing, engineered with this simulation tool, i...
#1Carlos Pascual(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 2
#2Julia de Castro(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 15
Last. Thomas Keller(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 45
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This paper demonstrates how the translucency of glass fiber-reinforced polymer (GFRP) laminates allows the derivation of their mechanical properties through optical measurements. Spectrophotometric, goniophotometric and tensile experiments were performed on unidirectional and cross-ply hand lay-up GFRP laminates with fiber volume fractions ranging from 0.15 to 0.45. An analytical model to predict the directional fiber volume fractionsand thus the mechanical properties of GFRP laminateshas been d...