Physical Sciences and Mathematics Commons^™

Wind For Schools: Fostering The Human Talent Supply Chain For A 20% Wind Energy Future, Ian Baring-Gould

Publications (E)

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America’s Wind for Schools project addresses these issues by:
• Developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses
• Installing small wind turbines at community “host” schools
• Implementing teacher training with interactive curricula at each host school.

Correlations Of Capacitance-Voltage Hysteresis With Thin-Film Cdte Solar Cell Performance During Accelerated Lifetime Testing, David S. Albin, Joseph A. Del Cueto

Publications (E)

In this paper we present the correlation of CdTe solar cell performance with capacitance-voltage hysteresis, defined presently as the difference in capacitance measured at zero-volt bias when collecting such data with different pre-measurement bias conditions. These correlations were obtained on CdTe cells stressed under conditions of 1-sun illumination, open-circuit bias, and an acceleration temperature of approximately 100 ºC.

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 …

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 …

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 …

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 …

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 …

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.

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 …

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 …

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.

U.S. Department Of Energy Commercial Reference Building Models Of The National Building Stock, Michael Deru, Kristin Field, Daniel Studer, Kyle Benne, Brent Griffith, Paul Torcellini, Bing Liu, Mark Halverson, Dave Winiarski, Michael Rosenberg, Mehry Yazdanian, Joe Huang, Drury Crawley

Publications (E)

The U.S. Department of Energy (DOE) Building Technologies Program has set the aggressive goal of producing marketable net-zero energy buildings by 2025. This goal will require collaboration between the DOE laboratories and the building industry. We developed standard or reference energy models for the most common commercial buildings to serve as starting points for energy efficiency research. These models represent fairly realistic buildings and typical construction practices. Fifteen commercial building types and one multifamily residential building were determined by consensus between DOE, the National Renewable Energy Laboratory, Pacific Northwest National Laboratory, and Lawrence Berkeley National Laboratory, and represent approximately two-thirds …

Wind Powering America Initiative: The Wind And Water Power Program (Wwpp), Energy Efficiency & Renewable Energy Information Center

Publications (E)

The U.S. Department of Energy's Wind Powering America initiative engages in technology market acceptance, barrier reduction, and technology deployment support activities. This fact sheet outlines ways in which the Wind Powering America team works to reduce barriers to appropriate wind energy deployment, primarily by focusing on six program areas: workforce development, communications and outreach, stakeholder analysis and resource assessment, wind technology technical support, wind power for Native Americans, and federal sector support and collaboration.

Solar Powering Your Community: A Guide For Local Governments, National Renewable Energy Laboratory

Publications (E)

The U.S. Department of Energy (DOE) designed this guide "Solar Powering Your Community: A Guide for Local Governments" to assist local government officials and stakeholders in designing and implementing strategic local solar plans. The 2011 edition contains the most recent lessons and successes from the 25 Solar America Cities and other communities promoting solar energy. Because DOE recognizes that there is no one path to solar market development, this guide introduces a range of policy and program options that can help a community build a local solar infrastructure.

State Of The States 2010: The Role Of Policy In Clean Energy Market Transformation, Elizabeth Doris, Rachel Gelman

Publications (E)

This report builds on the emerging body of literature seeking to identify quantitative connections between clean energy policy and renewable energy. The methods presented test the relationships between a broad set of policies and clean energy resources (energy efficiency, biomass, geothermal, solar, and wind). Energy efficiency findings are an initial foray into this type of analysis and indicate significant connections between reduced energy use and buildings codes, energy efficiency resource standards (in some cases), and electricity price. Renewable energy findings specify that there is most often a relationship between state policies and solar and wind development, indicating that while policies …

Guide To Community Solar: Utility, Private, And Non-Profit Project Development, Jason Coughlin, Jennifer Grove, Linda Irvine, Janet F. Jacobs, Sarah Johnson Phillips, Leslie Moynihan, Joseph Wiedman

Publications (E)

This guide is designed as a resource for those who want to develop community solar projects, from community organizers or solar energy advocates to government officials or utility managers.

Using Renewable Energy Purchases To Achieve Institutional Carbon Goals: A Review Of Current Practices And Considerations, Lori Bird, Jenny Sumner

Publications (E)

With organizations and individuals increasingly interested in accounting for their carbon emissions, greater attention is being placed on how to account for the benefits of various carbon mitigation actions available to consumers and businesses. Generally, organizations can address their own carbon emissions through energy efficiency, fuel switching, on-site renewable energy systems, renewable energy purchased from utilities or in the form of renewable energy certificates (RECs), and carbon offsets. This paper explores the role of green power and carbon offsets in carbon footprinting and the distinctions between the two products. It reviews how leading greenhouse gas (GHG) reporting programs treat green …