Oil, Gas, and Energy Commons^™

Use Of 2nd And 3rd Level Correlation Analysis For Studying Degradation In Polycrystalline Thin-Film Solar Cells, David S. Albin, Joseph A. Del Cueto, S. H. Demtsu, S. Bansal

Publications (E)

The correlation of stress-induced changes in the performance of laboratory-made CdTe solar cells with various 2^nd and 3^rd level metrics is discussed. The overall behavior of aggregated data showing how cell efficiency changes as a function of open-circuit voltage (V_oc), shortcircuit current density (J_sc), and fill factor (FF) is explained using a two-diode, PSpice model in which degradation is simulated by systematically changing model parameters. FF shows the highest correlation with performance during stress, and is subsequently shown to be most affected by shunt resistance, recombination and in some cases voltage-dependent collection. Large decreases …

Effect Of Hysteresis On Measurements Of Thin-Film Cell Performance, David S. Albin, Joseph A. Del Cueto

Publications (E)

Transient or hysteresis effects in polycrystalline thin film CdS/CdTe cells are a function of pre-measurement voltage bias and whether Cu is introduced as an intentional dopant during back contact fabrication. When Cu is added, the current-density (J) vs. voltage (V) measurements performed in a reverse-to-forward voltage direction will yield higher open-circuit voltage (V_oc), up to 10 mV, and smaller short-circuit current density (J_sc), by up to 2 mA/cm², relative to scanning voltage in a forward-to-reverse direction. The variation at the maximum power point, Pmax, is however small. The resulting variation in FF can be …

High Efficiency, Low Cost Solar Cells Manufactured Using ‘Silicon Ink’ On Thin Crystalline Silicon Wafers October 2009 - November 2010, Homer Antoniadis

Publications (E)

The objectives of Phase I (Feb – Oct 2009) include the development and demonstration of a 17% efficient 25mm x 25mm crystalline Silicon solar cell and a 16% efficient 125mm x 125mm crystalline Silicon solar cell, both produced by Ink-jet printing Silicon Ink on a thin crystalline Sil-icon wafer. To achieve these objectives, processing approaches were developed to print the Silicon Ink in a predetermined pattern to form a high efficiency selective emitter, remove the solvents in the Silicon Ink and fuse the deposited particle Silicon films. Additionally, standard solar cell manufacturing equipment with slightly modified processes were used to …

Hybrid Cooling Systems For Low-Temperature Geothermal Power Production, Andrea Ashwood, Desikan Bharathan

Publications (E)

The overall objective of this investigation is to identify and evaluate methods by which the net power output of an air-cooled geothermal power plant can be enhanced during hot ambient conditions using minimal amounts of water.

Geothermal power plants that use air-cooled heat rejection systems experience a decrease in power production during hot periods of the day. This decrease in power output typically coincides with the time when utilities need power to address high air conditioning loads. Hybrid cooling options, which use both air and water, have been studied for this report to assess how they might mitigate the net …

The Silver Spark For Nevada, Walt Borland, James A. Croce, Richard Seline

Publications (E)

The SILVER Spark for Nevada: Sustainable Innovation Leading a Vital Economic Renaissance

Nevada. A State of stark contrasts, with historic booms and devastating busts experienced throughout its modern history. A State frequently forced to reinvent itself as ever-evolving circumstances have demanded. A State that has been driven to the edge time after time and, yet again and again, has managed to discover another way to prosper. A State that now finds itself in a precarious position as the “Great Recession” hit it harder than any other and has left it struggling to recover.

As you will conclude by reading The …

Measuring Degradation Rates Without Irradiance Data, Steve Pulver, Daniel Cormode, Alex Cronin, Dirk C. Jordan, Ryan Smith, Sarah R. Kurtz

Publications (E)

A method to report PV system degradation rates without using irradiance data is demonstrated. First, a set of relative degradation rates are determined by comparing daily AC final yields from a group of PV systems relative to the average final yield of all the PV systems. Then, the difference between relative and absolute degradation rates is found from a statistical analysis. This approach is verified by comparing to methods that utilize irradiance data. This approach is significant because PV systems are often deployed without irradiance sensors, so the analysis method described here may enable measurements of degradation using data that …

Accelerated Stress Testing Of Hydrocarbon-Based Encapsulants For Medium-Concentration Cpv Applications, M. D. Kempe, T. J. Moricone, M. Kilkenny, J. Z. Zhang

Publications (E)

Concentrating photovoltaic (CPV) systems have great potential to reduce photovoltaic (PV) electricity costs because of the relatively low cost of optical components as compared to PV cells. A transparent polymeric material is used to optically couple the PV cell to optical components and is thus exposed to the concentrated light source at elevated temperatures. In this work polymeric encapsulant materials are positioned close to a Xenon arc lamp to expose them to ultraviolet radiation (UV) that is about 42 times as intense as sunlight. Furthermore, different glass types are used as filters to modify the spectral distribution of light in …

Creep In Photovoltaic Modules: Examining The Stability Of Polymeric Materials And Components, David C. Miller, Michael D. Kempe, Stephen H. Glick, Sarah R. Kurtz

Publications (E)

Interest in renewable energy has motivated the implementation of new polymeric materials in photovoltaic modules. Some of these are non-cross-linked thermoplastics, in which there is a potential for new behaviors to occur, including phase transformation and visco-elastic flow. Differential scanning calorimetry and rheometry data were obtained and then combined with existing site-specific time-temperature information in a theoretical analysis to estimate the displacement expected to occur during module service life. The analysis identified that, depending on the installation location, module configuration and/or mounting configuration, some of the thermoplastics are expected to undergo unacceptable physical displacement. While the examples here focus on …

Impacts Of Mid-Level Biofuel Content In Gasoline On Sidi Engine-Out And Tailpipe Particulate Matter Emissions, Xin He, John C. Ireland, Bradley T. Zigler, Matthew A. Ratcliff, Keith E. Knoll, Teresa L. Alleman, John T. Tester

Publications (E)

In this work, the influences of ethanol and iso-butanol blended with gasoline on engine-out and post three-way catalyst (TWC) particle size distribution and number concentration were studied using a General Motors (GM) 2.0L turbocharged spark ignition direct injection (SIDI) engine. The engine was operated using the production engine control unit (ECU) with a dynamometer controlling the engine speed and the accelerator pedal position controlling the engine load. A TSI Fast Mobility Particle Sizer (FMPS) spectrometer was used to measure the particle size distribution in the range from 5.6 to 560 nm with a sampling rate of 1 Hz. U.S. federal …

Considerations For How To Rate Cpv, Sarah R. Kurtz, Matthew Muller, Bill Marion, Keith Emery, Robert Mcconnell, Sandheep Surendran, Adrianne Kimber

Publications (E)

The concentrator photovoltaic (CPV) industry is introducing multiple products into the marketplace, but, as yet, the community has not embraced a unified method for assessing a nameplate rating. The choices of whether to use 850, 900, or 1000 W/m² for the direct-normal irradiance and whether to link the rating to ambient or cell temperature will affect how CPV modules are rated and compared with other technologies. This paper explores the qualitative and quantitative ramifications of these choices using data from two multi-junction CPV modules and two flat-plate modules.

"Buried-Anode" Technology Leads To Advanced Lithium Batteries, National Renewable Energy Laboratory

Publications (E)

A technology developed at the National Renewable Energy Laboratory has sparked a start-up company that has attracted funding from the Advanced Projects Research Agency-Energy (ARPA-E). Planar Energy, Inc. has licensed NREL's "buried-anode" technology and put it to work in solid-state lithium batteries. The company claims its large-format batteries can achieve triple the performance of today's lithium-ion batteries at half the cost, and if so, they could provide a significant boost to the emerging market for electric and plug-in hybrid vehicles.

Quantifying The Thermal Fatigue Of Cpv Modules, Nick Bosco, Sarah R. Kurtz

Publications (E)

A method is presented to quantify thermal fatigue in the CPV die-attach from meteorological data. A comparative study between cities demonstrates a significant difference in the accumulated damage. These differences are most sensitive to the number of larger (ΔT) thermal cycles experienced for a location. High frequency data (<1/min) may be required to most accurately employ this method.

Outdoor Pv Degradation Comparison, Dirk C. Jordan, R. M. Smith, C. R. Osterwald, E. Gelak, Sarah R. Kurtz

Publications (E)

As photovoltaic (PV) penetration of the power grid increases, it becomes vital to know how decreased power output may affect cost over time. In order to predict power delivery, the decline or degradation rates must be determined accurately. At the Performance and Energy Rating Testbed (PERT) at the Outdoor Test Facility (OTF) at the National Renewable Energy Laboratory (NREL) more than 40 modules from more than 10 different manufacturers were compared for their long-term outdoor stability. Because it can accommodate a large variety of modules in a limited footprint the PERT system is ideally suited to compare modules side-by-side under …

The Water-Energy Nexus In The American West, Douglas S. Kenney, Robert Wilkinson

Books, Reports, and Studies

This digital resource contains only an abstract, cover image and table of contents information from the published book.

Print copy of book is available in the University of Colorado’s Wise Law Library: http://lawpac.colorado.edu/record=b613233~S0

Contents: PART I : INTRODUCTION AND OVERVIEW: The water-energy nexus : methodologies, challenges and opportunities / Robert Wilkinson -- Energy, water and the natural environment / Melinda Kassen, Jack E. Williams -- PART IIA : WATER FOR ENERGY : FOSSIL FUELS: The coal conundrum / Kristen Averyt -- Oil shale and water / Bart Miller -- Managing produced water from coalbed methane production / Lawrence J. MacDonnell, …

Baselines Newsletter, No. 7, Winter/Spring 2011, University Of Colorado Boulder. Natural Resources Law Center

Baselines: The Natural Resources Law Center Newsletter (2007-2011)

No abstract provided.

Ua12/13 2011 Sustainability Report [Western Kentucky University], Wku Office Of Sustainability, Christian Ryan-Downing

Sustainability Publications and Resources

AASHE is an association of colleges and universities that are working to create a sustainable future. AASHE’s mission is to empower higher education to lead the sustainability transformation. The organization provides resources, professional development and a network of support to enable institutions of higher education to model and advance sustainability in everything they do, from governance and operations to education and research. For more information about AASHE, visit www.aashe.org.

In early 2010, Western Kentucky University became a charter member of the Association for the Advancement of Sustainability in Higher Education’s Sustainability Tracking, Assessment and Rating System (STARS). STARS® is a …

The Role Of Leadership In Safety Performance And Results, Halina E. Caravello

Walden Dissertations and Doctoral Studies

Employee injury rates in U.S. land-based operations in the energy industry are 2 to 3 times higher relative to other regions in the world. Although a rich literature exists on drivers of safety performance, no previous studies investigated factors influencing this elevated rate. Leadership has been identified as a key contributor to safety outcomes and this grounded theory study drew upon the full range leadership model, situational leadership, and leader-member exchange theories for the conceptual framework. Leadership aspects influencing safety performance were investigated through guided interviews of 27 study participants; data analyses included open and axial coding, and constant comparisons …

Wind Charged Plug-In Hybrid Electric Vehicle, John Patten, Nathan Christensen, Steven Srivastava, Gary Nola

Green Manufacturing Research Journal

With the emergence of electric vehicles (EVs), hybrid vehicles HVs) and plug-in hybrid electric vehicles (PHEVs) from a variety of automotive manufacturers, the electrical grid will need to meet new challenges in supplying the electricity required to charge these vehicles.  To help supply the electricity needed by these vehicles, we compared the electricity consumption of a modified Toyota Prius (PHEV) and the output of a small residential wind turbine over the course of one year.  Our research seeks to determine whether a small residential wind turbine can supply the necessary electricity demanded by the PHEV annually.

The Impact Of Driving Conditions On Phev Battery Performance, Nathan Christensen, John Patten, Steven Srivastava, Gary P. Nola

Green Manufacturing Research Journal

The battery performance of a modified Prius with a 5 kWh plug-in battery was documented for a year to determine the impact of environmental conditions and user attributes on vehicle performance.  Both fuel economy and pure electrical efficiency were compared to ambient temperature.  The fuel economy has a positive relationship with ambient temperature until approximately 70˚F where the efficiency begins to drop.  Electrical performance has a positive linear relationship with ambient temperature.  With the emergence of electric vehicles (EVs) and PHEVs from a variety of automotive manufacturers, information on EV and PHEV performance for consumers will become more important.

Simplified Methodology For Designing Parabolic Trough Solar Power Plants, Ricardo Vasquez Padilla

USF Tampa Graduate Theses and Dissertations

The performance of parabolic trough based solar power plants over the last 25 years has proven that this technology is an excellent alternative for the commercial power industry. Compared to conventional power plants, parabolic trough solar power plants produce significantly lower levels of carbon dioxide, although additional research is required to bring the cost of concentrator solar plants to a competitive level. The cost reduction is focused on three areas: thermodynamic efficiency improvements by research and development, scaling up of the unit size, and mass production of the equipment. The optimum design, performance simulation and cost analysis of the parabolic …