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Transportation Energy Futures: Project Overview and Findings

Description: The U.S. Department of Energy-sponsored Transportation Energy Futures (TEF) project examines how combining multiple strategies could reduce both GHG emissions and petroleum use by 80%. The project's primary objective was to help inform domestic decisions about transportation energy strategies, priorities, and investments, with an emphasis on previously underexplored opportunities related to energy efficiency and renewable energy in light-duty vehicles, non-light-duty vehicles, fuels, and transp… more
Date: March 1, 2013
Partner: UNT Libraries Government Documents Department

Results of First Outdoor Comparison Between Absolute Cavity Pyrgeometer (ACP) and Infrared Integrating Sphere (IRIS) Radiometer at PMOD

Description: The ACP and IRIS are developed to establish a world reference for calibrating pyrgeometers with traceability to SI units. The two radiometers are unwindowed with negligible spectral dependence, and traceable to SI units through the temperature scale (ITS-90). The first outdoor comparison between the two designs was held from January 28 to February 8, 2013 at the Physikalisch-Metorologisches Observatorium Davos (PMOD). The difference between the irradiance measured by ACP and that of IRIS was wi… more
Date: March 1, 2013
Creator: Reda, I.; Grobner, J.; Wacker, S. & Stoffel, T.
Partner: UNT Libraries Government Documents Department

Wind Plant Cost of Energy: Past and Future

Description: This presentation examines trends in wind plant cost of energy over the last several decades and discusses methods and examples of projections for future cost trends. First, the presentation explores cost trends for wind energy from the 1980s, where there had been an overall downward trend in wind plant energy costs. Underlying factors that influenced these trends, including turbine technology innovation for lower wind speed sites, are explored. Next, the presentation looks at projections for t… more
Date: March 1, 2013
Creator: Hand, M. Maureen
Partner: UNT Libraries Government Documents Department

Improvements in the Blackbody Calibration of Pyrgeometers

Description: Pyrgeometers are used to measure the atmospheric longwave irradiance throughout the ARM program sites. Previous calibrations of pyrgeometers using ARM/Eppley/NREL blackbody were consistent, but introduced a difference in the historical clear sky measured irradiance. This difference was believed to be in the order of 12 W/m2. In this poster we show the improvements to the blackbody and calibration methodology by comparing our results to the results of a group of pyrgeometers that were recently c… more
Date: March 1, 2008
Creator: Reda, I.; Grobner, J.; Stoffel, T.; Myers, D. & Forgan, B.
Partner: UNT Libraries Government Documents Department

Humidity, Temperature, and Voltage

Description: An update is given on the work of the PV Quality Assurance Task Force; Group 3: studying the effects of humidity, temperature, and voltage bias.
Date: March 1, 2012
Creator: Wohlgemuth, J.
Partner: UNT Libraries Government Documents Department

NREL Test-to-Failure Protocol [Presentation]

Description: The presentation describes the test-to-failure protocol that was developed and piloted at NREL, stressing PV modules with multiple applications of damp heat (with bias) and thermal cycling until they fail.
Date: March 1, 2012
Creator: Hacke, P.
Partner: UNT Libraries Government Documents Department

Renewable Energy 101 (Presentation)

Description: Presentation given at the 2012 Department of Homeland Security Renewable Energy Roundtable as an introduction to renewable technologies and applications.
Date: March 1, 2012
Creator: Walker, A.
Partner: UNT Libraries Government Documents Department

Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems

Description: Many concentrating photovoltaic (CPV) systems use a polymeric encapsulant to couple and optical component and/or coverglass to the cell. In that location, the encapsulation improves the transmission of concentrated optical flux through interface(s), while protecting the cell from the environment. The durability of encapsulation materials, however, is not well established relative to the desired service life of 30 years. Therefore, we have initiated a screen test to identify the field-induced fa… more
Date: March 1, 2012
Creator: Miller, D. C.; Muller, M.; Kempe, M. D.; Araki, K.; Kennedy, C. E. & Kurtz, S. R.
Partner: UNT Libraries Government Documents Department

Getting from Goals to Projects in the Ground (Presentation)

Description: Presentation given at the 2012 Department of Homeland Security Renewable Energy Roundtable on Energy Savings Performance Contracts (ESPCs) and Power Purchase Agreements (PPAs) for Renewable Energy (RE).
Date: March 1, 2012
Creator: Springer, B.
Partner: UNT Libraries Government Documents Department

Heat Pump Water Heater Modeling in EnergyPlus

Description: This presentation summarizes NREL's development of a HPWH model for use in hourly building energy simulation programs, such as BEopt; this presentation was given at the Building America Stakeholder meeting on March 1, 2012, in Austin, Texas.
Date: March 1, 2012
Creator: Wilson, E. & Christensen, C.
Partner: UNT Libraries Government Documents Department

Considerations for a Standardized Test for Potential-Induced Degradation of Crystalline Silicon PV Modules

Description: Over the past decade, there have been observations of module degradation and power loss because of the stress that system voltage bias exerts. This results in part from qualification tests and standards note adequately evaluating for the durability of modules to the long-term effects of high voltage bias that they experience in fielded arrays. This talk deals with factors for consideration, progress, and information still needed for a standardized test for degradation due to system voltage stre… more
Date: March 1, 2012
Creator: Hacke, P.
Partner: UNT Libraries Government Documents Department

Giant Leap Forward Toward Quality Assurance of PV Modules

Description: The presentation describes the composition of and motivation for the International PV QA Task Force, then describes the presentations and discussion that occurred at the workshop on Feb. 29th, 2012.
Date: March 1, 2012
Creator: Kurtz, S.; Wohlgemuth, J.; Sample, T. & Yamamichi, M.
Partner: UNT Libraries Government Documents Department

Comparison of Accelerated Testing with Modeling to Predict Lifetime of CPV Solder Layers

Description: Concentrating photovoltaic (CPV) cell assemblies can fail due to thermomechanical fatigue in the die-attach layer. In this presentation, we show the latest results from our computational model of thermomechanical fatigue. The model is used to estimate the relative lifetime of cell assemblies exposed to various temperature histories consistent with service and with accelerated testing. We also present early results from thermal cycling experiments designed to help validate the computational mode… more
Date: March 1, 2012
Creator: Silverman, T. J.; Bosco, N. & Kurtz, S.
Partner: UNT Libraries Government Documents Department

CIGS Material and Device Stability: A Processing Perspective

Description: This is a general overview of CIGS material and device fundamentals. In the first part, the basic features of high efficiency CIGS absorbers and devices are described. In the second part, some examples of previous collaboration with Shell Solar CIGSS graded absorbers and devices are shown to illustrate how process information was used to correct deviations and improve the performance and stability.
Date: March 1, 2012
Creator: Ramanathan, K.
Partner: UNT Libraries Government Documents Department

Status of U.S. FCEV and Infrastructure Learning Demonstration Project

Description: Presented at the Japan Hydrogen and Fuel Cell Demonstration Project (JHFC), 1 March 2011, Tokyo, Japan. This presentation summarizes the status of U.S. fuel cell electric vehicles and infrastructure learning demonstration project.
Date: March 1, 2011
Creator: Wipke, K.; Sprik, S.; Kurtz, J.; Ramsden, T.; Ainscough, C. & Saur, G.
Partner: UNT Libraries Government Documents Department

Experience with CPV Module Failures at NREL

Description: The failures and performance issues associated with three years of on-sun testing of CPV modules are discussed. Pictures of various failure mechanisms and performance issues are presented. A wide array of CPV module failures and performance issues have been experienced at NREL. Many of the modules are prototypes and have not been through qualification testing. It is assumed that the qualification test would have captured many of the problems. Internal lens soiling due to condensation is not cur… more
Date: March 1, 2012
Creator: Muller, M.
Partner: UNT Libraries Government Documents Department

Predicting the Performance of Edge Seal Materials for PV

Description: Edge seal materials were evaluated using a 100-nm film of Ca deposited on glass and laminated to another glass substrate. As moisture penetrates the package it converts the Ca metal to transparent CaOH2 giving a clear indication of the depth to which moisture has entered. Using this method, we have exposed test samples to a variety of temperature and humidity conditions ranging from 45C and 10% RH up to 85C and 85% RH, to ultraviolet radiation and to mechanical stress. We are able to show that … more
Date: March 1, 2012
Creator: Kempe, M.; Panchagade, D.; Dameron, A. & Reese, M.
Partner: UNT Libraries Government Documents Department

Cell Data Sheet Specification

Description: The presentation shows a brief status report on the development of a specification being considered by IEC TC82 WG7 for a concentrator cell data sheet and solicits suggestions from the community.
Date: March 1, 2012
Creator: Kurtz, S.
Partner: UNT Libraries Government Documents Department

Improving Air-Conditioner and Heat Pump Modeling

Description: A new approach to modeling residential air conditioners and heat pumps allows users to model systems by specifying only the more readily-available SEER/EER/HSPF-type metrics. Manufacturer data was used to generate full sets of model inputs for over 450 heat pumps and air conditioners. A sensitivity analysis identified which inputs can be safely defaulted 'behind-the-scenes' without negatively impacting the reliability of energy simulations.
Date: March 1, 2012
Creator: Winkler, J.
Partner: UNT Libraries Government Documents Department

ESPC Intro and ESPC/PPAs for RE (Presentation)

Description: Presentation given at the 2012 Department of Homeland Security Renewable Energy Roundtable on Energy Savings Performance Contracts (ESPCs) and Power Purchase Agreements (PPAs) for Renewable Energy (RE)
Date: March 1, 2012
Creator: Dahle, D.
Partner: UNT Libraries Government Documents Department
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