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Full-Text Articles in Physical Sciences and Mathematics

The Silver Spark For Nevada, Walt Borland, James A. Croce, Richard Seline Mar 2011

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 …


Accelerated Stress Testing Of Hydrocarbon-Based Encapsulants For Medium-Concentration Cpv Applications, M. D. Kempe, T. J. Moricone, M. Kilkenny, J. Z. Zhang Feb 2011

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 Feb 2011

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 Feb 2011

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 Feb 2011

"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 Feb 2011

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 Feb 2011

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 Feb 2011

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 Feb 2011

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 Jan 2011

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.


State Of The States 2010: The Role Of Policy In Clean Energy Market Transformation, Elizabeth Doris, Rachel Gelman Jan 2011

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 Jan 2011

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 Jan 2011

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 …


The Role Of Energy Storage With Renewable Electricity Generation, Paul Denholm, Erik Ela, Brendan Kirby, Michael Milligan Jan 2010

The Role Of Energy Storage With Renewable Electricity Generation, Paul Denholm, Erik Ela, Brendan Kirby, Michael Milligan

Publications (E)

Renewable energy sources, such as wind and solar, have vast potential to reduce dependence on fossil fuels and greenhouse gas emissions in the electric sector. Climate change concerns, state initiatives including renewable portfolio standards, and consumer efforts are resulting in increased deployments of both technologies. Both solar photovoltaics (PV) and wind energy have variable and uncertain (sometimes referred to as “intermittent”) output, which are unlike the dispatchable sources used for the majority of electricity generation in the United States. The variability of these sources has led to concerns regarding the reliability of an electric grid that derives a large fraction …


Nrel: A Year In Clean Energy Innovations: A Review Of Nrel's Feature Stories, National Renewable Energy Laboratory Jan 2010

Nrel: A Year In Clean Energy Innovations: A Review Of Nrel's Feature Stories, National Renewable Energy Laboratory

Publications (E)

The National Renewable Energy Laboratory (NREL) is the nation’s primary laboratory for renewable energy and energy efficiency research and development.

NREL’s mission and strategy are focused on advancing the U.S. Department of Energy’s and our nation’s energy goals. The laboratory’s scientists and researchers support critical market objectives to accelerate research from scientific innovations to market-viable alternative energy solutions. At the core of this strategic direction are NREL’s research and technology development competencies. These areas span from understanding renewable resources for energy, to the conversion of these resources to renewable electricity and fuels, and ultimately to the use of renewable electricity …


Green Initiatives, Paul Andricopulos, Ned Thomas Jan 2010

Green Initiatives, Paul Andricopulos, Ned Thomas

Publications (E)

City practices incorporating energy conservation methods.


Economic Investigation Of Community-Scale Versus Building Scale Net-Zero Energy, N. Fernandez, S. Katipamula, M. R. Brambley, T. A. Reddy Dec 2009

Economic Investigation Of Community-Scale Versus Building Scale Net-Zero Energy, N. Fernandez, S. Katipamula, M. R. Brambley, T. A. Reddy

Publications (E)

The study presented in this report examines issues concerning whether achieving net-zero energy performance at the community scale provides economic and potentially overall efficiency advantages over strategies focused on individual buildings.


Insights And Opportunities: Technologies, Policies, And Markets For Clean Energy Solutions, Douglas J. Arent Nov 2009

Insights And Opportunities: Technologies, Policies, And Markets For Clean Energy Solutions, Douglas J. Arent

Publications (E)

A presentation highlighting how strategic energy analysis can affect technologies, policies, and markets for clean energy solutions. This includes an overview of some of NREL's models and tools as well as results from laboratory analysis.


State Of The States 2009: Renewable Energy Development And The Role Of Policy, Elizabeth Doris, Joyce Mclaren, Victoria Healey, Stephen Hockett Oct 2009

State Of The States 2009: Renewable Energy Development And The Role Of Policy, Elizabeth Doris, Joyce Mclaren, Victoria Healey, Stephen Hockett

Publications (E)

As U.S. states increasingly focus on developing renewable energy resources, there is a need to track the progress of development, as well as the policies and support mechanisms being implemented to encourage this development. Beyond tracking, the evaluation of policy measures is necessary to determine their effectiveness, guide future efforts, and efficiently allocate resources. This report addresses each of these needs. It provides a detailed picture of the status of renewable energy development in each of the U.S. states using a variety of metrics and discusses the policies being used to encourage this development. The report then explores the context …


Rebuilding After Disaster: Going Green From The Ground Up, U.S. Department Of Energy Jan 2009

Rebuilding After Disaster: Going Green From The Ground Up, U.S. Department Of Energy

Publications (E)

If you’re a leader in a community that has met with disaster and must be rebuilt, this guide is for you. It’s intended to show how communities—big or small—can incorporate green principles and technologies like energy efficiency and renewable energy into their rebuilding plans. The information in this guide is based on the real-life experiences of two U.S. Department of Energy (DOE) teams. One team worked with city leaders in New Orleans, Louisiana, after hurricanes Katrina and Rita in 2005, and the other assisted community leaders in Greensburg, Kansas, after a devastating tornado in 2007. Although the two communities are …