Engineering

Research Papers/Topics in Engineering

Carrier Transport and Recombination In A-SI: H PIN Solar Cells in Dark and Under Illumination

Abstract A study has been carried out on the forward bias dark current and the short circuit current-open circuit voltage characteristics of a-Si: H pin solar cells over wide range of illumination intensities. Results are presented with superposition of these characteristics over extended current voltage regimes. This and the observed separation between these characteristics are consistent with the arguments presented based on first principle arguments.

Numerical Simulation of the Direct Application of Compound Parabolic Concentrators to a Single Effect Basin Solar Still

As regional shortages of fresh water become more prevalent, solar distillation using a single-effect basin holds promise as a method to bring low-cost, clean, and ecologically-responsible water to remote area dwellers. Compound parabolic concentrators (CPCs) can be used to direct more light onto the still increasing the throughput and efficiency of these passive solar devices. A computer program has been developed that uses the properties of materials and the solar energy characteristics of t...

3D-mapping optimization of embodied energy of transportation

Resources Conservation and Recycling, Jan 1, 2007The recent development of Google Earth, an information service that provides imagery and three dimensional data depicting the entire Earth, provides an opportunity to use a new method of navigating information to save energy in the real world. Google Earth uses Keyhole Markup Language (KML) for modeling and storing geographic features and information for display in the Google Earth Client. This paper will analyze the potential of this novel and...

Reducing greenhouse gas emissions by inducing energy conservation and distributed generation from elimination of electric utility customer charges

This paper quantifies the increased green house gas emissions and negative effect on energy conservation (or “efficiency penalty”) due to electric rate structures that employ an unavoidable customer charge. First the extent of customer charges was determined from a nationwide survey of U.S. electric tariffs. To eliminate the customer charge nationally while maintaining a fixed sum for electric companies for a given amount of electricity, an increase of 7.12% in the residential electrical ...

Optimization of open circuit voltage in amorphous silicon solar cells with mixed-phase (amorphous+nanocrystalline) p-type contacts of low nanocrystalline content

Both the origins of the high open circuit voltages (VOC) in amorphous silicon solar cells having p layers prepared with very high hydrogen dilution and the physical structure of these optimum p layers remain poorly understood topics, with several studies offering conflicting views. This work attempts to overcome the limitations of previous studies by combining insights available from electronic measurements, real time spectroscopic ellipsometry, atomic force microscopy, and both high-resoluti...

Energy conservation from systematic tire pressure regulation

The majority of U.S. drivers do not consistently monitor the tire pressures in their vehicles. The 2000 TREAD Act, which requires automakers to gradually provide tire pressure monitoring systems for vehicles sold in the U.S. will correct this problem for new vehicles. This law does not impact the problem in previously deployed vehicles, which have a turnover time of 20 years. A solution is provided here to address under-inflated tires on the current 220 million vehicles and the concomitant wa...

Thermodynamic limitations to nuclear energy deployment as a greenhouse gas mitigation technology

To both replace fossil-fuel-energy use and meet the future energy demands, nuclear energy production would have to increase by 10.5% per year from 2010 to 2050. This large growth rate creates a cannibalistic effect, where nuclear energy must be used to supply the energy for future nuclear power plants. This study showed that the limit of ore grade to offset greenhouse gas emissions is significantly higher than the purely thermodynamic limit set by energy payback times found in the literature....

Industrial Symbiosis for Very Large Scale Photovoltaic Manufacturing

In order to stabilize the global climate the world’s governments must make significant commitments to drastically reduce global greenhouse gas (GHG) emissions. One of the most promising methods of curbing GHG emissions is a world transition from fossil fuels to renewable sources of energy. Solar photovoltaic (PV) cells offer a technically sustainable solution to the projected enormous future energy demands. This article explores utilizing industrial symbiosis to obtain economies of scale an...

Increasing PV Velocity by Reinvesting the Nuclear Energy Insurance Subsidy into Large Scale Solar Photovoltaic Production

As the debate over the future of energy grows, often nuclear energy production is pitted against solar photovoltaic energy conversion. There is a widespread belief that solar cannot compete with nuclear energy economically without government subsidies. The continued and widespread belief in the economic viability of nuclear energy, however, is predicated in part on government-mandated limitation on the liability of the nuclear industry. To demonstrate the magnitude of this nuclear energy insu...

Optimizing Design of Household Scale Hybrid Solar Photovoltaic + Combined Heat and Power Systems for Ontario

This paper investigates the feasibility of implementing a hybrid solar photovoltaic (PV) + combined heat and power (CHP) and battery bank system for a residential application to generate reliable base load power to the grid in Ontario. Deploying PV on a large-scale has a penetration level threshold due to the inherent power supply intermittency associated with the solar resource. By creating a hybrid PV+CHP system there is potential of increasing the PV penetration level. One year of one seco...

Expanding Photovoltaic Penetration with Residential Distributed Generation from Hybrid Solar Photovoltaic Combined Heat and Power Systems

The recent development of small scale combined heat and power (CHP) systems has provided the opportunity for in-house power backup of residential-scale photovoltaic (PV) arrays. This paper investigates the potential of deploying a distributed network of PV CHP hybrid systems in order increase the PV penetration level in the U.S. The temporal distribution of solar flux, electrical and heating requirements for representative U.S. single family residences were analyzed and the results clearly sh...

Cleaner production via industrial symbiosis in glass and largescale solar photovoltaic manufacturing

In order to alleviate production costs and increase the environmental performance of solar photovoltaic manufacturing, an eco-industrial park for GW-scale production of PV is proposed. This article quantifies the inputs and outputs for the glass manufacturing component of such a system using standard manufacturing techniques. Utilizing industrial symbiosis in this way, potential reductions for such a plant were found to be about 30,000 tons/year in raw materials and over 220,000 GJ/year in em...

Leveraging Photovoltaic Technology for Sustainable Development in Ontario's Aboriginal Communities

"The Ontario feed-in tariff (FIT) for solar photovoltaic (PV) technology has provided Ontario's Aboriginal communities with an opportunity to i) weaken the cycle of poverty; ii) directly counteract climate change by producing renewable energy; and iii) become more self-sufficient. This paper critically analyzes the technical, cultural, and economic viability of leveraging the FIT for PV to provide green electricity and revenue to assist First Nations communities in sustainable development. A ...

3-D Printing of Open Source Appropriate Technologies for Self-Directed Sustainable Development

The technological evolution of the 3-D printer, widespread internet access and inexpensive computing has made a new means of open design capable of accelerating self-directed sustainable development. This study critically examines how open source 3-D printers, such as the RepRap and Fab@home, enable the use of designs in the public domain to fabricate open source appropriate technology (OSAT), which are easily and economically made from readily available resources by local communities to meet...

Dispatch Strategy and Model for Hybrid Photovoltaic and Trigeneration Power Systems

The advent of small scale combined heat and power (CHP) systems has provided the opportunity for in-house power backup of residential-scale photovoltaic (PV) arrays. These hybrid systems enjoy a symbiotic relationship between components, but have large thermal energy wastes when operated to provide 100% of the electric load. In a novel hybrid system is proposed here of PV-trigeneration. In order to reduce waste from excess heat, an absorption chiller has been proposed to utilize the CHP-produ...


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