Engineering

Research Papers/Topics in Engineering

Improved parametric empirical determination of module short circuit current for modelling and optimization of solar photovoltaic systems

Correct modelling of solar photovoltaic (PV) system yields is necessary to optimize system design, improve reliability of projected outputs to ensure favourable project financing and to facilitate proper operations and maintenance. An improved methodology for fine resolution modelling of PV systems is presented using module short-circuit current (Isc) at 5-min time-scales, and clearly identifies pertinent error mechanisms that arise when working at this high resolution. This work used a modif...

Open-Source Development of Solar Photovoltaic Technology

The rise of solar photovoltaic (PV) technology as a driver of rural electrification in the developing world and a contributor to climate change mitigation suggests that innovations enhancing PV efficiency and scalability could make considerable strides in reducing both poverty and greenhouse gas emissions. The nearly global access to the solar resource coupled to innovation-driven decreases in the costs of PV provides a path for an renewable energy source to accelerate sustainable development...

Open-Source Colorimeter

The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A 3-D printable, open-source colorimeter utilizing only open-source hardware and software solutions and readily available discrete components is discussed and its performance compared to a commercial porta...

Optimizing limited solar roof access by exergy analysis of solar thermal, photovoltaic, and hybrid photovoltaic thermal systems

An exergy analysis was performed to compare a conventional (1) two panel photovoltaic solar thermal hybrid (PVT x2) system, (2) side by side photovoltaic and solar thermal (PV + T) system, (3) two module photovoltaic (PV) system and (4) a two panel solar thermal (T x2) system with identical absorber areas to determine the superior technical solar energy systems for applications with a limited roof area. Three locations, Detroit, Denver and Phoenix, were simulated due to their differences in a...

Effects of spectral albedo on solar photovoltaic devices

Although the spectral effects of direct and diffuse radiation on solar photovoltaic (PV) performance are relatively well understood, recent investigations have shown that there can be a spectral bias introduced due to albedo from common ground surfaces that can impact the optimal selection of PV materials for a known location. This paper extends analysis to the effects of spectral bias due to the specular reflectivity of 22 commonly occurring surface materials (both man-made and natural) and ...

Simulations of greenhouse gas emission reductions from low-cost hybrid solar photovoltaic and cogeneration systems for new communities

Recent work has shown that small-scale combined heat and power (CHP) and solar photovoltaic (PV) technologies have symbiotic relationships, which enable coverage of technical weaknesses while providing the potential of significant greenhouse gas emission reductions at the residential level. With the reductions in the cost of PV systems and the increasing maturity of CHP systems an opportunity exists for widespread commercialization of the technology, particularly for new construction. In orde...

Mobile Open-Source Solar-Powered 3-D Printers for Distributed Manufacturing in Off-Grid Communities

Manufacturing in areas of the developing world that lack electricity severely restricts the technical sophistication of what is produced. More than a billion people with no access to electricity still have access to some imported higher-technologies; however, these often lack customization and often appropriateness for their community. Open source appropriate technology (OSAT) can over­come this challenge, but one of the key impediments to the more rapid development and distri­bution of OSA...

DESIGN AND FABRICATION OF SINGLE PHASE INDUCTION MOTOR FOR NUMERICAL MACHINE COMPLEX

The energy sector plays a major role in driving Kenya’s economy. The need to conceive, develop and sustain energy generating sources cannot be underestimated.  Being a growing economy, Kenya therefore needs to redirect her effort in production of self-sustaining energy generating sources. It is in this line that the government through the ministry of industrialization, energy and vision 2030 sought to establish the Numerical Machine Complex, which serves as a hub for fabrication...

Evaluation of the dangers of corrosion in marine piping system using carbon steel c-1040.

The research was undertaken to ascertain the level and ingress of corrosion in carbon steel C-1040.

Optimization of annealing cycles for electric output in outdoor conditions for amorphous silicon photovoltaic–thermal systems

Previous studies with fixed operating temperatures have shown that hydrogenated amorphous silicon (a-Si:H) was a promising absorber layer for solar photovoltaic–thermal (PVT) systems because of (a) a low temperature coefficient and (b) the opportunity to reverse light induced degradation with thermal annealing. This study further refined the simulation of the optimal dispatch strategy for a-Si:H based PVT by studying annealing cycles and analysis of the degradation at other operating temper...

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. Therefor...

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...


76 - 90 Of 805 Results