Natural & Applied Sciences

Research Papers/Topics in Natural & Applied Sciences

DESARROLLO DE UN SISTEMA DE MONITOREO DE RADIACIÓN SOLAR BASADO EN UN ESPECTRÓMETRO DE AMPLIO ESPECTRO

RESUMEN La eficiencia cuántica de materiales fotovoltaicos depende de la longitud de onda de la radiación incidente, el espectro solar influye en la producción de energía producida por estos sistemas. En el presente trabajo, se diseñó y construyó un prototipo funcional de un sistema de medición de radiación solar (global y difusa) basado en un espectrómetro de amplio espectro para el monitoreo solar en Cochabamba, Bolivia, conjuntamente con un sistema similar instalado en Kingston, Ontario.

The Effect of Hybrid Photovoltaic Thermal Device Operating Conditions on Intrinsic Layer Thickness Optimization of Hydrogenated Amorphous Silicon Solar Cells

Historically, the design of hybrid solar photovoltaic thermal (PVT) systems has focused on cooling crystalline silicon (c-Si)-based photovoltaic (PV) devices to avoid temperature-related losses. This approach neglects the associated performance losses in the thermal system and leads to a decrease in the overall exergy of the system. Consequently, this paper explores the use of hydrogenated amorphous silicon (a-Si:H) as an absorber material for PVT in an effort to maintain higher and more favo...

Prediction of Energy Effects on Photovoltaic Systems due to Snowfall Events

The accurate prediction of yields from photovoltaic systems (PV) is critical for their proper operation and financing, and in northern latitudes the effects of snowfall on yield can become significant. This work provides methods for identifying snowfall effects from commonly collected performance data, and recommends a model to allow for prediction of these effects based solely on meteorological time series. The model was validated with data from two large-scale (>8MW) operational PV plants. ...

Life Cycle Analysis of Silane Recycling in Amorphous Silicon-Based Solar Photovoltaic Manufacturing

Amorphous silicon (a-Si:H)-based solar cells have the lowest ecological impact of photovoltaic (PV) materials. In order to continue to improve the environmental performance of PV manufacturing using proposed industrial symbiosis techniques, this paper performs a life cycle analysis (LCA) on both conventional 1-GW scaled a-Si:H-based single junction and a-Si:H/microcrystalline-Si:H tandem cell solar PV manufacturing plants and such plants coupled to silane recycling plants. Both the energy con...

Progress in Indium Gallium Nitride Materials for Solar Photovoltaic Energy Conversion

The world requires inexpensive, reliable, and sustainable energy sources. Solar photovoltaic (PV) technology, which converts sunlight directly into electricity, is an enormously promising solution to our energy challenges. This promise increases as the efficiencies are improved. One straightforward method of increasing PV device efficiency is to utilize multi-junction cells, each of which is responsible for absorbing a different range of wavelengths in the solar spectrum. Indium gallium nitri...

Environmental Impacts of Distributed Manufacturing from 3-D Printing of Polymer Components and Products

Although additive layer manufacturing is well established for rapid prototyping the low throughput and historic costs have prevented mass-scale adoption. The recent development of the RepRap, an open source self-replicating rapid prototyper, has made low-cost 3-D printers readily available to the public at reasonable prices (

The effect of spectral albedo on amorphous silicon and crystalline silicon solar photovoltaic device performance

In this paper the theory of mismatch factor of the terrestrial solar spectrum is extended to more accurately represent the irradiance available to specific types of photovoltaic (PV) materials from surface albedo. Using spectra derived from the SBDART radiative transfer model, the effects of a spectrally responsive albedo are illustrated by the differences between the spectrally weighted albedo of hydrogenated amorphous silicon (a-Si:H) and crystalline silicon (c-Si)-based PV technology compa...

Open-Source Nanotechnology: Solutions to a Modern Intellectual Property Tragedy

Despite being an extremely active area for patent applications, nanotechnology development is being impaired by current intellectual property law. In contrast to other emerging fields at their times, nanotechnology was born as the Bayh–Dole Act enabled universities to lock down fundamental research effectively preventing open competition. Both technical complexity and bureaucratic mishandling of nanotechnology patent applications have created a dense patent thicket of overlapping claims and...

Life cycle analysis of distributed recycling of post-consumer high density polyethylene for 3-D printing filament

The growth of desktop 3-D printers is driving an interest in recycled 3-D printer filament to reduce costs of distributed production. Life cycle analysis studies were performed on the recycling of high density polyethylene into filament suitable for additive layer manufacturing with 3-D printers. The conventional centralized recycling system for high population density and low population density rural locations was compared to the proposed in home, distributed recycling system. This system wo...

Mechanical properties of components fabricated with open-source 3-D printers under realistic environmental conditions

The recent development of the RepRap, an open-source self-replicating rapid prototyper, has made 3-D polymer-based printers readily available to the public at low costs (

The effects of dispatch strategy on electrical performance of amorphous silicon-based solar photovoltaic-thermal systems

Previous work has shown that high-temperature short-term spike thermal annealing of hydrogenated amorphous silicon (a-Si:H) photovoltaic thermal (PVT) systems results in higher electrical energy output. The relationship between temperature and performance of a-Si:H PVT is not simple as high temperatures during thermal annealing improves the immediate electrical performance following an anneal, but during the anneal it creates a marked drop in electrical performance. In addition, the power gen...

Design of Multijunction Photovoltaic Cells Optimized for Varied Atmospheric Conditions

Band gap engineering provides an opportunity to not only provide higher overall conversion efficiencies of the reference AM1.5 spectra but also customize PV device design for specific geographic locations and microenvironments based on atmospheric conditions characteristic to that particular location. Indium gallium nitride and other PV materials offer the opportunity for limited bandgap engineering to match spectra. The effects of atmospheric conditions such as aerosols, cloud cover, water v...

It is Time to Move Research Expenditures to the Denominator in University Metrics

An unintended consequence of using “research expenditures” as a figure of merit for universities is to reduce the research output per dollar invested by discouraging the diffusion of superior, lower-cost, open-source scientific equipment.

Light Induced Changes in Two Distinct Defect States at and Below Mid-gap in a-Si:H

e inconsistencies associated with the common simple method of evaluating the quality and stability of hydrogenated amorphous silicon (a-Si:H) materials for solar cell applications from just the magnitude of subgap absorption (a(E)) are addressed in this study. The approach taken in this study is to characterize the entire a(E) spectrum by its derivatives, d[a(E)]/dE. Results are presented and discussed for two a-Si:H thin film materials differing in deposition rate by an order of magnitude, w...

Desarrollo de un sistema de monitoreo de radiación solar basado en un espectrómetro de amplio espectro y análisis de resultados preliminares

Se diseñó y construyó un prototipo funcional de un sistema de medición de radiación solar (global y difusa) basado en un espectrómetro de amplio espectro (UVA, VIS y parte del IR cercano) para el monitoreo solar en Cochabamba, Bolivia, conjuntamente con un sistema similar instalado en Ontario, Canadá. Los datos obtenidos en dos regiones con características geográficas muy distintas ayudaran en el estudio y optimización de materiales fotovoltaicos, para su implementación en diferent...


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