Engineering

Engineering Research Papers/Topics

Applications of Open Source 3-D Printing on Small Farms

There is growing evidence that low-cost open-source 3-D printers can reduce costs by enabling distributed manufacturing of substitutes for both specialty equipment and conventional mass-manufactured products. The rate of 3-D printable designs under open licenses is growing exponentially and there are already hundreds of designs applicable to small-scale organic farming. It has also been hypothesized that this technology could assist sustainable development in rural communities that rely on sm...

Return on Investment for Open Source Hardware Development

The availability of free and open source hardware designs that can be replicated with low-cost 3-D printers provide large values to scientists that need highly-customized low-volume production scientific equipment. Digital manufacturing technologies have only recently become widespread and the return on investment (ROI) was not clear, so funding for open hardware development was historically sparse. This paper clarifies a method for determining an ROI for FOSH scientific hardware development....

Performance of U.S. hybrid distributed energy systems: Solar photovoltaic, battery and combined heat and power

Until recently, the relatively high levelized cost of electricity from solar photovoltaic (PV) technology limited deployment; however, recent cost reductions, combined with various financial incentives and innovative financing techniques, have made PV fully competitive with conventional sources in many American regions. In addition, the costs of electrical storage have also declined enough to make PV + battery systems potentially economically viable for a mass-scale off-grid low-emission tran...

Double amorphous silicon-carbide p-layer structures producing highly stabilized pin-type protocrystalline silicon multilayer solar cells

We have applied double p-type amorphous silicon-carbide p-a-SiC:H layer structures to pin-type protocrystalline silicon pc-Si:H multilayer solar cells. The less-pronounced initialshort-wavelength quantum efficiency variation against the biased voltage and the wide overlap of dark current—voltage JD-V and short-circuit current—open-circuit voltage  Jsc-Voc characteristics prove that the double p-a-SiC:H layer structure successfully reduces recombination at the p/ i interface. Therefore, w...

Light-induced defect states in hydrogenated amorphous silicon centered around 1.0 and 1.2 eV from the conduction band edge

To take into account the presence of multiple light-induced defect states in hydrogenated amorphous silicon (a-Si:H) the evolution of the entire spectra of photoconductive subgap absorption, a(hn ), has been analyzed. Using this approach two distinctly different light-induced defect states centeredaround 1.0 and 1.2 eV from the conduction band edge are clearly identified. Results are presented on their evolution and respective effects on carrier recombination that clearly point to the importa...

Photovoltaic System Performance Enhancement With Non-Tracking Planar Concentrators: Experimental Results and Bi-Directional Reflectance Function (BDRF) Based Modelling

Non-tracking planar concentrators are a low-cost method of increasing the performance of traditional solar photovoltaic (PV) systems. This paper presents new methodologies for properly modeling this type of system design and experimental results using a bi-directional reflectance function (BDRF) of non-ideal surfaces rather than traditional geometric optics. This methodology allows for the evaluation and optimization of specular and non-specular reflectors in planar concentration systems. In ...

Feeding Everyone: Solving the Food Crisis in Event of Global Catastrophes that Kill Crops or Obscure the Sun

Mass human starvation is currently likely if global agricultural production is dramatically reduced for several years following a global catastrophe: e.g. super volcanic eruption, asteroid or comet impact, nuclear winter, abrupt climate change, super weed, extirpating crop pathogen, super bacterium, or super crop pest. This study summarizes the severity and probabilities of such scenarios, and provides an order of magnitude technical analysis comparing caloric requirements of all humans for f...

Impact of Snow and Ground Interference on Photovoltaic Electric System Performance

Assessing snow-related energy losses is necessary for accurate predictions of photovoltaic (PV) performance. A PV test platform with seven portrait-oriented modules placed at four tilt angles (0°, 15°, 30°, and 45°) was installed in Calumet, MI, USA, to measure the energy loss in this snowy climate. As a best-case snow-shedding configuration, similar to a carport or a plain sloped roof, three of the test modules were rack-mounted high enough to prevent surface interference. The opposite e...

Distributed manufacturing with 3-D printing: a case study of recreational vehicle solar photovoltaic mounting systems

For the first time, low-cost open-source 3-D printing provides the potential for distributed manufacturing at the household scale of customized, high-value, and complex products. To explore the potential of this type of ultra-distributed manufacturing, which has been shown to reduce environmental impact compared to conventional manufacturing, this paper presents a case study of a 3-D printable parametric design for recreational vehicle (RV) solar photovoltaic (PV) racking systems. The design ...

Technical viability of mobile solar photovoltaic systems for indigenous nomadic communities in northern latitudes

This study assesses the viability of photovoltaic (PV) technology in northern latitudes as a part of energy supply system for remote nomadic camps of indigenous communities involved in reindeer husbandry. Two boundary locations were analyzed: southern Yakutia, Russia, 56°41′N; and the northernmost area in Norway, Finnmark, 68°51′N. Sixteen scenarios were simulated based on energy consumption, light sources and electric load schedules. The results show that PV-based systems are beneficia...

Levelized cost of electricity for solar photovoltaic, battery and cogen hybrid systems

The technological development and economic of scale for solar photovoltaic (PV), batteries and combined heat and power (CHP) have led to the technical potential for a mass-scale transition to off-grid home electricity production for a significant number of utility customers. However, economic projections on complex hybrid systems utilizing these three technologies is challenging and no comprehensive method is available for guiding decision makers. This paper provides a new method of quantifyi...

High-Efficiency Solar-Powered 3-D Printers for Sustainable Development

The release of the open source 3-D printer known as the RepRap (a self-Replicating Rapid prototyper) resulted in the potential for distributed manufacturing of products for significantly lower costs than conventional manufacturing. This development, coupled with open source-appropriate technology (OSAT), has enabled the opportunity for 3-D printers to be used for sustainable development. In this context, OSAT provides the opportunity to modify and improve the physical designs of their printer...

Emerging Economic Viability of Grid Defection in a Northern Climate Using Solar Hybrid Systems

High demand for photovoltaic (PV), battery, and small-scale combined heat and power (CHP) technologies are driving a virtuous cycle of technological improvements and cost reductions in off-grid electric systems that increasingly compete with the grid market. Using a case study in the Upper Peninsula of Michigan, this paper quantifies the economic viability of off-grid PV+battery+CHP adoption and evaluates potential implications for grid-based utility models. The analysis shows that already so...

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...

Retraining Investment for U.S. Transition from Coal to Solar Photovoltaic Employment

Although coal remains the largest source of electricity in the U.S., a combination of factors is driving a decrease in profitability and employment in the coal-sector. Meanwhile, the solar photovoltaic (PV) industry is growing rapidly in the U.S. and generating many jobs that represent employment opportunities for laid off coal workers. In order to determine the viability of a smooth transition from coal to PV-related employment, this paper provides an analysis of the cost to retrain current ...


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