1,656 research outputs found
Sliver Solar Cells
Sliver solar cells are thin, mono-crystalline silicon solar cells, fabricated using micro-machining techniques combined with standard solar cell fabrication technology. Sliver solar modules can be efficient, low cost, bifacial, transparent, flexible, shadow-tolerant, and lightweight. Sliver modules require only 5 to 10% of the pure silicon and less than 5% of the wafer starts per MWp of factory output when compared with conventional photovoltaic modules. At ANU, we have produced 20% efficient Sliver solar cells using a robust, optimised cell fabrication process described in this paper. We have devised a rapid, reliable and simple method for extracting Sliver cells from a Sliver wafer, and methods for assembling modularised Sliver cell sub-modules. The method for forming these Sliver sub-modules, along with a low-cost method for rapidly forming reliable electrical interconnections, are presented. Using the sub-module approach, we describe low-cost methods for assembling and encapsulating Sliver cells into a range of module designs
Water Quality Relationships to Concentrations of Pfiesteria-like Organisms in Virginia Estuaries for 1998
A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large number of zero counts; and; c) there were no marked changes involving increasing abundance during the study that could be related to environmental factors
Water Quality Relationships to Concentrations of Pfiesteria-like organisms in Virginia Estuaries for 1998.
A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large number of zero counts; and; c) there were no marked changes involving increasing abundance during the study that could be related to environmental factors
Sliver® modules - a crystalline silicon technology of the future
A new technique has been devised for the manufacture of thin (<60µm) highly efficient single crystalline solar cells. Novel methods of encapsulating these Sliver® solar cells have also been devised. Narrow grooves are formed through a 1-2mm thick wafer. Device processing (diffusion, oxidation, deposition) is performed on the wafer, so that each of the narrow strips becomes a solar cell. The strips are then detached from the wafer and laid on their sides, which greatly increases the surface area of solar cell that can be obtained from the wafer. Further gains of a factor of two can be obtained by utilising a simple method of static concentration. Large decreases in processing effort (up to 30-fold) and silicon usage (up to 10-fold) per m2 of module are possible. The size, thickness and bifacial nature of the cells create the opportunity for a wide variety of module architectures and applications
Espécies bioindicadoras na conservação da biodiversidade dos Açores : metodologias de avaliação de impacte ambiental na gestão dos recursos naturais dos Açores
A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.[…]
A Universidade dos Açores, por via de projectos de investigação que desenvolve, tem dado um importante contributo para a preservação dos ecossistemas dos Açores. Um exemplo vem do projecto EDEN Habitats Açores (http://www.eden-azores.com). Neste projecto foram desenvolvidas metodologias para assegurar a identificação, para 8 habitats tipo, naturais e agrícolas (comunidades arbóreo-arbustivas e herbáceas), de espécies bioindicadoras chave (insectos, aranhas e plantas), bem como a criação e manutenção de uma Entomoteca da biodiversidade de invertebrados do arquipélago. A caracterização molecular de bioindicadores complementa a coleção, repartida por 40 subcolecções por ilha e habitat dos Açores. A estrutura do projecto EDEN Habitats Açores, financiado pelo Fundo Regional Ciência e Tecnologia PROEMPREGO e pela Fundação Luso-Americana para o Desenvolvimento (FLAD) avalia o impacte da acção antropogénica nos ecossistemas insulares dos Açores, mediante a identificação e uso de espécies bioindicadoras e pretende a incorporação destes organismos nas metodologias de análise e gestão de impacte ambiental e/ou nos processos de decisão económica e governamental.
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Embodied energy of Sliver® modules
Sliver® solar cells, invented and developed at the ANU, allow a reduction in the consumption of silicon by a factor of 5 to 12 compared with state of the art conventional crystalline silicon modules, resulting in a decrease in the number of wafers that need to be processed to produce a kW rated system by a factor of 15 to 30. Both of these features reduce the embodied energy of Sliver® modules. We have calculated an energy payback time of 1.5 years for Sliver® modules compared to 4.1 years for conventional crystalline silicon modules. The equivalent greenhouse gas emissions embodied in Sliver® modules also compares favourably to emissions from fossil fuel sources used for the generation of electricity in Australia
Recent developments in SLIVER cell technology
SLIVER cells, which were invented and developed at the ANU, allow the production of thin silicon cells and modules from standard silicon wafers, without the requirement for silicon deposition or any other expensive steps. Reductions in silicon consumption by a factor of 7-12 and reductions in the number of wafers that need to be processed per MW of a factor of 12-40 are possible. SLIVER cells are fabricated with sophisticated processing on high quality single crystal silicon substrates. SLIVER cell efficiencies above 19% are the highest reported for any commercially-viable thin-film cell. In this paper we report that a new SLIVER process has been devised that has the potential to double the throughput of a factory compared with the older SLIVER process
Modelling of silver modules incorporating a lambertian rear reflector
Modules incorporating cells which are bifacial and narrow can make use of rear reflectors to capture most of the incident sunlight while covering only a fraction of the module area with cells. Sliver® cells, invented and developed at the ANU, meet these criteria. In this paper we analyse the performance limits of such modules for the case where a diffuse (lambertian) reflector is used. The analysis is carried out for various cell thicknesses, cell spacings and reflectivities of the lambertian reflector. The results show that excellent performance can be realised despite the simplicity of the structure. A module with a 50% coverage with 70µm thick cells can capture up to 84% of the light entering the module. Importantly, the performance of this kind of module is insensitive to module orientation. The results of the analytical model are compared with ray tracing studies and measurements and are shown to be in good agreement. It is concluded that significant module cost reductions can be achieved for only modest reductions in performance by covering half or less of the module surface with cells
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