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Full-Text Articles in Power and Energy

Aerial Radiation Detection Identification And Measurement System Detector Material Comparison Study, Benjamin C. Troxell, Kacey D. Mcgee, Christina L. Dugan Apr 2022

Aerial Radiation Detection Identification And Measurement System Detector Material Comparison Study, Benjamin C. Troxell, Kacey D. Mcgee, Christina L. Dugan

Faculty Publications

The 20th Chemical Biological Radiological Nuclear and Explosives Command (CBRNE) currently utilizes an airborne sodium iodide gamma and beta detection system to map radiation fields over large areas of interest. The 20th CBRNE explored emergent detector technologies utilizing two detection materials; thallium-activated cesium iodide and high purity germanium (HPGe). These detectors were simulated at various altitudes and compared to background measurements. The sodium iodide detector failed to provide isotopic discrimination at distance. The thallium-activated cesium iodide CsI(Tl) detector provided sufficient absolute efficiency and energy resolution to identify isotopics at distance. The HPGe detector provided the best energy resolution. However, current …


Cost Analysis Of Optimized Islanded Energy Systems In A Dispersed Air Base Conflict, Jay F. Pearson, Torrey J. Wagner, Justin D. Delorit Sep 2020

Cost Analysis Of Optimized Islanded Energy Systems In A Dispersed Air Base Conflict, Jay F. Pearson, Torrey J. Wagner, Justin D. Delorit

Faculty Publications

The United States Air Force has implemented a dispersed air base strategy to enhance mission effectiveness for near-peer conflicts. Asset dispersal places many smaller bases across a wide geographic area, which increases resupply requirements and logistical complexity. Hybrid energy systems reduce resupply requirements through sustainable, off-grid energy production. This paper presents a novel hybrid energy renewable delivery system (HERDS) model capable of (1) selecting the optimal hybrid energy system design that meets demand at the lowest net present cost and (2) optimizing the delivery of the selected system using existing Air Force cargo aircraft. The novelty of the model’s capabilities …


Meeting Temporary Facility Energy Demand With Climate-Optimized Off-Grid Energy Systems, Jay F. Pearson, Torrey J. Wagner, Justin D. Delorit, Steven J. Schuldt Jun 2020

Meeting Temporary Facility Energy Demand With Climate-Optimized Off-Grid Energy Systems, Jay F. Pearson, Torrey J. Wagner, Justin D. Delorit, Steven J. Schuldt

Faculty Publications

Remote and contingency operations, including military and disaster-relief activities, often require the use of temporary facilities powered by inefficient diesel generators that are expensive to operate and maintain. Site planners can reduce operating costs by increasing shelter insulation and augmenting generators with photovoltaic-battery hybrid energy systems, but they must select the optimal design configuration based on the region’s climate to meet the power demand at the lowest cost. To assist planners, this paper proposes an innovative, climate-optimized, hybrid energy system selection model capable of selecting the facility insulation type, solar array size, and battery backup system to minimize the annual …


Machine Learning Modeling Of Horizontal Photovoltaics Using Weather And Location Data, Christil Pasion, Torrey J. Wagner, Clay Koschnick, Steven J. Schuldt, Jada B. Williams, Kevin Hallinan May 2020

Machine Learning Modeling Of Horizontal Photovoltaics Using Weather And Location Data, Christil Pasion, Torrey J. Wagner, Clay Koschnick, Steven J. Schuldt, Jada B. Williams, Kevin Hallinan

Faculty Publications

Solar energy is a key renewable energy source; however, its intermittent nature and potential for use in distributed systems make power prediction an important aspect of grid integration. This research analyzed a variety of machine learning techniques to predict power output for horizontal solar panels using 14 months of data collected from 12 northern-hemisphere locations. We performed our data collection and analysis in the absence of irradiation data—an approach not commonly found in prior literature. Using latitude, month, hour, ambient temperature, pressure, humidity, wind speed, and cloud ceiling as independent variables, a distributed random forest regression algorithm modeled the combined …


On-Site And External Energy Harvesting In Underground Wireless, Usman Raza, Abdul Salam Apr 2020

On-Site And External Energy Harvesting In Underground Wireless, Usman Raza, Abdul Salam

Faculty Publications

Energy efficiency is vital for uninterrupted long-term operation of wireless underground communication nodes in the field of decision agriculture. In this paper, energy harvesting and wireless power transfer techniques are discussed with applications in underground wireless communications (UWC). Various external wireless power transfer techniques are explored. Moreover, key energy harvesting technologies are presented that utilize available energy sources in the field such as vibration, solar, and wind. In this regard, the Electromagnetic(EM)- and Magnetic Induction(MI)-based approaches are explained. Furthermore, the vibration-based energy harvesting models are reviewed as well. These energy harvesting approaches lead to design of an efficient wireless underground …


E700xd Portable Doppler Radar Energy Systems Analysis, Brandon M. Bailey, Torrey J. Wagner, Jada Williams Dec 2019

E700xd Portable Doppler Radar Energy Systems Analysis, Brandon M. Bailey, Torrey J. Wagner, Jada Williams

Faculty Publications

Occurring in industrialized nations, inexpensive and abundantly available power is routinely taken for granted. However, energy resilience and to a lesser extent price are key concerns when considering potential solutions for disaster response, disaster relief, or military operations. The Department of Defense (DoD) currently uses a 5 kW generator to power the E700XD portable Doppler radar system when grid power is unavailable [1]. While the radar has an approximate power consumption of 2.5 kW, there is a potential for higher demand due to weather conditions [2]. This paper examines the cost of operating a currently installed generator, compared to the …


Analyzing The Efficiency Of Horizontal Photovoltaic Cells In Various Climate Regions, Parker A. Hines, Torrey J. Wagner, Clay M. Koschnick, Steven J. Schuldt Jun 2019

Analyzing The Efficiency Of Horizontal Photovoltaic Cells In Various Climate Regions, Parker A. Hines, Torrey J. Wagner, Clay M. Koschnick, Steven J. Schuldt

Faculty Publications

This research presents the development of linear regression models to predict horizontal photovoltaic power output. We collected a dataset from 14 global Department of Defense (DoD) installations over a timeframe of one year using an experimental apparatus, resulting in 24,179 usable data points. We developed a linear model to predict power output, which incorporated site-specific weather and geographical characteristics, along with Köppen-Geiger climate classifications in order to determine the effect of adding climate to the model. After performing a Wald test between the full model and a reduced model without Köppen-Geiger climate variables, it was determined that including Köppen-Geiger climate …


36% Reduction In Fuel Resupply Using A Hybrid Generator & Battery System For An Austere Location, David J. Chester, Torrey J. Wagner, Douglas S. Dudis Mar 2019

36% Reduction In Fuel Resupply Using A Hybrid Generator & Battery System For An Austere Location, David J. Chester, Torrey J. Wagner, Douglas S. Dudis

Faculty Publications

The DOD energy policy is to increase energy security resiliency, and mitigate costs in the use and management of energy[1] Forward operating bases (FOBs) are remote, austere base camps that support an operationally defined mission with a limited or no ability to draw from an energy grid and have historically relied on diesel-powered generators for the primary production of energy.[2] Generators are sized to meet a theoretical peak demand, but steady state loads are far below this peak, resulting in under-loaded generators.[3] Under-loaded diesel generators decrease efficiency and increase the need for maintenance, affecting the lifespan of …


A Sustainable Prototype For Renewable Energy: Optimized Prime-Power Generator Solar Array Replacement, Nathan Thomsen, Torrey J. Wagner, Andrew J. Hoisington, Steven J. Schuldt Jan 2019

A Sustainable Prototype For Renewable Energy: Optimized Prime-Power Generator Solar Array Replacement, Nathan Thomsen, Torrey J. Wagner, Andrew J. Hoisington, Steven J. Schuldt

Faculty Publications

Remote locations such as disaster relief camps, isolated arctic communities, and military forward operating bases are disconnected from traditional power grids forcing them to rely on diesel generators with a total installed capacity of 10,000 MW worldwide. The generators require a constant resupply of fuel, resulting in increased operating costs, negative environmental impacts, and challenging fuel logistics. To enhance remote site sustainability, planners can develop stand-alone photovoltaic-battery systems to replace existing prime power generators. This paper presents the development of a novel cost-performance model capable of optimizing solar array and Li-ion battery storage size by generating tradeoffs between minimizing initial …


Photovoltaic System Optimization For An Austere Location Using Time Series Data, Torrey J. Wagner, Eric Lang, Warren Assink, Douglas S. Dudis Jun 2018

Photovoltaic System Optimization For An Austere Location Using Time Series Data, Torrey J. Wagner, Eric Lang, Warren Assink, Douglas S. Dudis

Faculty Publications

In this work we test experimental photovoltaic, storage and generator technologies and investigate their potential to meet austere location energy needs. After defining the energy requirements and insolation of a 1,100-person base, we develop a microgrid model and simulation. Cost optimizations were then performed using hourly time-series data to explore the cost and performance trade-space of a PV-battery-generator system. The work highlights the cost of resiliency and the dependencies of optimum system component sizes on duration and the fully burdened cost of fuel.


Benchmarking Approach For Empirical Comparison Of Pricing Models In Drms, Seif Azghandi, Kenneth M. Hopkinson, Kennard R. Laviers Nov 2016

Benchmarking Approach For Empirical Comparison Of Pricing Models In Drms, Seif Azghandi, Kenneth M. Hopkinson, Kennard R. Laviers

Faculty Publications

emand response management systems often involve the use of pricing schemes to motivate the efficient use of electrical power. Achieving this efficiency requires the detection of electrical power patterns. The detection of these patterns normally involves use of non-linear, quasi-non-linear, and at times linear data pattern detection models. The behavioural disparities of these models and specifically when used for a specific set of data make it hard to select the most efficient model. The contribution of this study is devising an empirical benchmark (reference) ( perfect ) control pricing (PCP) model through which various models are compared in order to …


Con-Resistant Trust For Improved Reliability In A Smart Grid Special Protection System, Crystal M. Shipman, Kenneth M. Hopkinson, Juan L. Lopez Jr. Feb 2015

Con-Resistant Trust For Improved Reliability In A Smart Grid Special Protection System, Crystal M. Shipman, Kenneth M. Hopkinson, Juan L. Lopez Jr.

Faculty Publications

This paper applies a con-resistant trust mechanism to improve the performance of a communications-based special protection system to enhance its effectiveness and resiliency. Smart grids incorporate modern information technologies to increase reliability and efficiency through better situational awareness. However, with the benefits of this new technology come the added risks associated with threats and vulnerabilities to the technology and to the critical infrastructure it supports. The research in this paper uses con-resistant trust to quickly identify malicious or malfunctioning (untrustworthy) protection system nodes to mitigate instabilities. The con-resistant trust mechanism allows protection system nodes to make trust assessments based on …


Defect Levels In Cu₂Znsn(Sₓse₁₋ₓ)₄ Solar Cells Probed By Current-Mode Deep Level Transient Spectroscopy, S. Das, S. K. Chaudhuri, R. N. Bhattacharya, K. C. Mandal May 2014

Defect Levels In Cu₂Znsn(Sₓse₁₋ₓ)₄ Solar Cells Probed By Current-Mode Deep Level Transient Spectroscopy, S. Das, S. K. Chaudhuri, R. N. Bhattacharya, K. C. Mandal

Faculty Publications

No abstract provided.


A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue Jan 2014

A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue

Faculty Publications

We report the fabrication and evaluation of a platinum nanowire network as a highly efficient current collector for solid oxide fuel cells (SOFCs). The ink of carbon-black supported platinum nanoparticles was sprayed onto the cathode. After firing, the carbon black was oxidized and disappeared as carbon dioxide gas while the platinum nanoparticles connect with one another, forming a tree-branch-like nanowire network. The diameters of the nanowires range from 100 nm to 400 nm. Compared to a conventional platinum paste current collector, the polarization resistance of the PrBaCo2O5+δ (PBCO) cathode with a nanowire current collector was reduced …


Modeling Of Chemical-Mechanical Couplings In Anode-Supported Solid Oxide Fuel Cells And Reliability Analysis, Xinfang Jin, Xingjian Xue Jan 2014

Modeling Of Chemical-Mechanical Couplings In Anode-Supported Solid Oxide Fuel Cells And Reliability Analysis, Xinfang Jin, Xingjian Xue

Faculty Publications

Oxygen ionic transport in conducting ceramics is an important mechanism enabling solid oxide fuel cell (SOFC) technology. The multi-physicochemical processes lead to the fact that the distribution of oxygen vacancy site fraction is not uniform in a positive-electrode electrolyte negative-electrode (PEN) assembly. Different oxygen vacancy concentrations induce different volumetric expansion of ceramics, resulting in complicated chemical–mechanical coupling phenomena and chemical stress in SOFCs. In this research, a mathematical model is developed to study oxygen ionic transport induced chemical stress in an SOFC. The model is validated using experimental polarization curves. Comprehensive simulations are performed to investigate chemical stress distribution in …


Micro Modeling Study Of Cathode/Electrolyte Interfacial Stresses For Solid Oxide Fuel Cells, Xinfang Jin, Xingjian Xue May 2013

Micro Modeling Study Of Cathode/Electrolyte Interfacial Stresses For Solid Oxide Fuel Cells, Xinfang Jin, Xingjian Xue

Faculty Publications

Delamination of the cathode/electrolyte interface is an important degradation phenomenon in solid oxide fuel cells (SOFCs). While the thermal stress has been widely recognized as one of the major reasons for such delamination failures, the role of chemical stress does not receive too much attention. In this paper, a micro-model is developed to study the cathode/electrolyte interfacial stresses, coupling oxygen ion transport process with structural mechanics. Results indicate that the distributions of chemical stress are very complicated at the cathode/electrolyte interface and show different patterns from those of thermal stress. The maximum principal stresses take place at the cathode/electrolyte interface …


Biparametric Analyses Of Charge Trapping In Cd0.9Zn0.1Te Based Virtual Frisch Grid Detectors, S. K. Chaudhuri, K. J. Zavalla, R. M. Krishna, K. C. Mandal Feb 2013

Biparametric Analyses Of Charge Trapping In Cd0.9Zn0.1Te Based Virtual Frisch Grid Detectors, S. K. Chaudhuri, K. J. Zavalla, R. M. Krishna, K. C. Mandal

Faculty Publications

No abstract provided.


Experimental Determination Of Electron-Hole Pair Creation Energy In 4h-Sic Epitaxial Layer: An Absolute Calibration Approach, S. K. Chaudhuri, K. J. Zavalla, K. C. Mandal Jan 2013

Experimental Determination Of Electron-Hole Pair Creation Energy In 4h-Sic Epitaxial Layer: An Absolute Calibration Approach, S. K. Chaudhuri, K. J. Zavalla, K. C. Mandal

Faculty Publications

No abstract provided.


A Ceramic-Anode Supported Low Temperature Solid Oxide Fuel Cell, Hanping Ding, Junjie Ge, Xingjian Xue Mar 2012

A Ceramic-Anode Supported Low Temperature Solid Oxide Fuel Cell, Hanping Ding, Junjie Ge, Xingjian Xue

Faculty Publications

We report the fabrication and evaluation of a ceramic-anode supported button cell LSCM-SDC/SDC/PBSC (thickness 400 μm/20 μm/20 μm). The anode/electrolyte assembly LSCM-SDC/SDC was co-fired at low temperature of 1250°C, where a slight amount of CuO was mixed with LSCM. The CuO (20.3 wt%) were impregnated into the porous substrate to enhance current collecting effect. The cell exhibited power density of 596 mWcm−2 and 381 mWcm−2 at 700°C with wet hydrogen and methane as the fuel respectively, where the silver paste was used as current collectors, the highest performance up to date for the cells with metal oxide anodes at this …


Characterization Of Deep Levels In N-Type And Semi-Insulating 4h-Sic Epitaxial Layers By Thermally Stimulated Current Spectroscopy, P. G. Muzykov, Ramesh Madhu Krishna, K. C. Mandal Jan 2012

Characterization Of Deep Levels In N-Type And Semi-Insulating 4h-Sic Epitaxial Layers By Thermally Stimulated Current Spectroscopy, P. G. Muzykov, Ramesh Madhu Krishna, K. C. Mandal

Faculty Publications

No abstract provided.


Optimization Design Of Electrodes For Anode-Supported Solid Oxide Fuel Cells Via Genetic Algorithm, Junxiang Shi, Xingjian Xue Dec 2010

Optimization Design Of Electrodes For Anode-Supported Solid Oxide Fuel Cells Via Genetic Algorithm, Junxiang Shi, Xingjian Xue

Faculty Publications

Porous electrode is the critical component of solid-oxide fuel cells (SOFCs) and provides a functional material backbone for multi-physicochemical processes. Model based electrode designs could significantly improve SOFC performance. This task is usually performed via parameter studies for simple case and assumed property distributions for graded electrodes. When nonlinearly coupled multiparameters of electrodes are considered, it could be very difficult for the model based parameter study method to effectively and systematically search the design space. In this research, the optimization approach with a genetic algorithm is demonstrated for this purpose. An anode-supported proton conducting SOFC integrated with a fuel supply …


Time-Resolved Photoluminescence Of Quaternary Alingan-Based Multiple Quantum Wells, Mee-Yi Ryu, C. Q. Chen, E. Kuokstis, J. W. Yang, Grigory Simin, M. Asif Khan, G. G. Sim, P. W. Yu May 2002

Time-Resolved Photoluminescence Of Quaternary Alingan-Based Multiple Quantum Wells, Mee-Yi Ryu, C. Q. Chen, E. Kuokstis, J. W. Yang, Grigory Simin, M. Asif Khan, G. G. Sim, P. W. Yu

Faculty Publications

Time-resolvedphotoluminescence(PL)dynamics has been studied in AlInGaN/AlInGaN multiple quantum wells(MQWs) grown by a pulsed metalorganic chemical vapor deposition (PMOCVD) procedure. The PL decay kinetics was found to be sensitive to the emission energy and temperature. The PL decay time increases with decreasing emission energy, which is a characteristic of localized carrier/exciton recombination due to alloy fluctuations. Its temperature dependence shows radiative recombination to be the dominant process at low temperatures, indicating a high quality of PMOCVD grown quaternary AlInGaN MQWs and establishing them as promising structures for the active region of deep ultraviolet light emitting diodes.


Pulsed Atomic Layer Epitaxy Of Quaternary Alingan Layers, J. Zhang, E. Kuokstis, Q. Fareed, H. Wang, J. Yang, Grigory Simin, M. Asif Khan, R. Gaska, M. Shur Aug 2001

Pulsed Atomic Layer Epitaxy Of Quaternary Alingan Layers, J. Zhang, E. Kuokstis, Q. Fareed, H. Wang, J. Yang, Grigory Simin, M. Asif Khan, R. Gaska, M. Shur

Faculty Publications

In this letter, we report on a material deposition scheme for quaternary AlxInyGa1−x–yN layers using a pulsed atomic layer epitaxy (PALE) technique. The PALE approach allows accurate control of the quaternary layer composition and thickness by simply changing the number of aluminum,indium, and gallium pulses in a unit cell and the number of unit cell repeats. Using PALE, AlInGaN layers with Al mole fractions in excess of 40% and strong room-temperature photoluminescence peaks at 280 nm can easily be grown even at temperatures lower than 800 °C.


Low‐Cost Technique For Preparing N‐Sb2S3/P‐Si Heterojunction Solar Cells, O. Savadogo, K. C. Mandal Jul 1993

Low‐Cost Technique For Preparing N‐Sb2S3/P‐Si Heterojunction Solar Cells, O. Savadogo, K. C. Mandal

Faculty Publications

No abstract provided.