Uncertainty and sensitivity analysis for photovoltaic system modeling. (open access)

Uncertainty and sensitivity analysis for photovoltaic system modeling.

We report an uncertainty and sensitivity analysis for modeling DC energy from photovoltaic systems. We consider two systems, each comprised of a single module using either crystalline silicon or CdTe cells, and located either at Albuquerque, NM, or Golden, CO. Output from a PV system is predicted by a sequence of models. Uncertainty in the output of each model is quantified by empirical distributions of each model's residuals. We sample these distributions to propagate uncertainty through the sequence of models to obtain an empirical distribution for each PV system's output. We considered models that: (1) translate measured global horizontal, direct and global diffuse irradiance to plane-of-array irradiance; (2) estimate effective irradiance from plane-of-array irradiance; (3) predict cell temperature; and (4) estimate DC voltage, current and power. We found that the uncertainty in PV system output to be relatively small, on the order of 1% for daily energy. Four alternative models were considered for the POA irradiance modeling step; we did not find the choice of one of these models to be of great significance. However, we observed that the POA irradiance model introduced a bias of upwards of 5% of daily energy which translates directly to a systematic difference in …
Date: December 1, 2013
Creator: Hansen, Clifford W.; Pohl, Andrew Phillip & Jordan, Dirk
Object Type: Report
System: The UNT Digital Library
Transformations, Inc. Net Zero Energy Communities, Devens, Easthampton, Townsend, Massachusetts (Fact Sheet) (open access)

Transformations, Inc. Net Zero Energy Communities, Devens, Easthampton, Townsend, Massachusetts (Fact Sheet)

In 2009, Transformations, Inc. partnered with U.S. Department of Energy (DOE) Building America team Building Science Corporation (BSC) to build new net zero energy houses in three developments in Massachusetts. The company has been developing strategies for cost-effective super-insulated homes in the New England market since 2006. After years of using various construction techniques, it has developed a specific set of assemblies and specifications that achieve a 44.9% reduction in energy use compared with a home built to the 2009 International Residential Code, qualifying the houses for the DOE's Challenge Home. The super-insulated houses provide data for several research topics in a cold climate. BSC studied the moisture risks in double stud walls insulated with open cell spray foam and cellulose. The mini-split air source heat pump (ASHP) research focused on the range of temperatures experienced in bedrooms as well as the homeowners' perceptions of equipment performance. BSC also examined the developer's financing options for the photovoltaic (PV) systems, which take advantage of Solar Renewable Energy Certificates, local incentives, and state and federal tax credits.
Date: November 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Discovery of GeV Emission tfrom the Circinus Galaxy with the Fermi-Lat (open access)

Discovery of GeV Emission tfrom the Circinus Galaxy with the Fermi-Lat

None
Date: November 14, 2013
Creator: Hayashida, Masaaki; Stawarz, Lukasz; Cheung, Chi C.; Bechtol, Keith; Madejski, Greg M.; Ajello, Marco et al.
Object Type: Article
System: The UNT Digital Library
Clean Cities 2012 Annual Metrics Report (open access)

Clean Cities 2012 Annual Metrics Report

The U.S. Department of Energy's (DOE) Clean Cities program advances the nation's economic, environmental, and energy security by supporting local actions to cut petroleum use in transportation. A national network of nearly 100 Clean Cities coalitions brings together stakeholders in the public and private sectors to deploy alternative and renewable fuels, idle-reduction measures, fuel economy improvements, and new transportation technologies, as they emerge. Each year DOE asks Clean Cities coordinators to submit annual reports of their activities and accomplishments for the previous calendar year. Data and information are submitted via an online database that is maintained as part of the Alternative Fuels Data Center (AFDC) at the National Renewable Energy Laboratory (NREL). Coordinators submit a range of data that characterizes the membership, funding, projects, and activities of their coalitions. They also submit data about sales of alternative fuels, deployment of alternative fuel vehicles (AFVs) and hybrid electric vehicles (HEVs), idle-reduction initiatives, fuel economy activities, and programs to reduce vehicle miles traveled (VMT). NREL analyzes the data and translates them into petroleum-use reduction impacts, which are summarized in this report.
Date: December 1, 2013
Creator: Johnson, C.
Object Type: Report
System: The UNT Digital Library

Thriving Through Tough Times

None
Date: October 30, 2013
Creator: Huber, A M & Moyle, A R
Object Type: Presentation
System: The UNT Digital Library
Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: 2012 State of Technology and Projections to 2017 (open access)

Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: 2012 State of Technology and Projections to 2017

This report summarizes the economic impact of the work performed at PNNL during FY12 to improve fast pyrolysis oil upgrading via hydrotreating. A comparison is made between the projected economic outcome and the actual results based on experimental data. Sustainability metrics are also included.
Date: August 27, 2013
Creator: Jones, Susanne B. & Snowden-Swan, Lesley J.
Object Type: Report
System: The UNT Digital Library
Test Report for Permanganate and Cold Strontium Strike for Tank 241-AN-102 (open access)

Test Report for Permanganate and Cold Strontium Strike for Tank 241-AN-102

Tanks 241-AN-102 and 241-AN-107 supernatants contain soluble Sr-90 and transuranic elements that require removal prior to vitrification to comply with the Waste Treatment and Immobilization Plant immobilized low-activity waste specification (WTP Contract, DE-AC27-01RV 14136, Specification 2.2.2.8, "Radionuclide Concentration Limitations") and the U.S. Nuclear Regulatory Commission provisional agreement on waste incidental to reprocessing (letter, Paperiello, C. J., "Classification of Hanford Low-Activity Tank Waste Fraction"). These two tanks have high concentrations of organics and organic complexants and are referred to as complexant concentrate tanks. A precipitation process using sodium permanganate (NaMnO{sub 4}) and strontium nitrate (Sr(NO{sub 3}){sub 2}) was developed and tested with tank waste samples to precipitate Sr-90 and transuranic elements from the supernate (PNWD-3141, Optimization of Sr/TRU Removal Conditions with Samples of AN-102 Tank Waste). Testing documented in this report was conducted to further evaluate the use of the strontium nitrate/sodium permanganate process in tank farms with a retention time of up to 12 months. Previous testing was focused on developing a process for deployment in the ultrafiltration vessels in the Waste Treatment and Immobilization Plant. This environment is different from tank farms in two important ways: the waste is diluted in the Waste Treatment and Immobilization Plant to ~5.5 …
Date: November 27, 2013
Creator: Duncan, James B.; Huber, Heinz J. & Smalley, Colleen S.
Object Type: Report
System: The UNT Digital Library
Development of Alternative Technetium Waste Forms (open access)

Development of Alternative Technetium Waste Forms

The UREX+1 process is under consideration for the separation of transuranic elements from spent nuclear fuel. The first steps of this process extract the fission product technicium-99 ({sup 99}Tc) into an organic phase containing tributylphosphate together with uranium. Treatment of this stream requires the separation of Tc from U and placement into a suitable waste storage form. A potential candidate waste form involves immobilizing the Tc as an alloy with either excess metallic zirconium or stainless steel. Although Tc-Zr alloys seem to be promising waste forms, alternative materials must be investigated. Innovative studies related to the synthesis and behavior of a different class of Tc materials will increase the scientific knowledge related to development of Tc waste forms. These studies will also provide a better understanding of the behavior of {sup 99}Tc in repository conditions. A literature survey has selected promising alternative waste forms for further study: technetium metallic alloys, nitrides, oxides, sulfides, and pertechnetate salts. The goals of this project are to 1) synthesize and structurally characterize relevant technetium materials that may be considered as waste forms, 2) investigate material behavior in solution under different conditions of temperature, electrochemical potential, and radiation, and 3) predict the long-term behavior of …
Date: September 13, 2013
Creator: Czerwinski, Kenneth
Object Type: Report
System: The UNT Digital Library
Thermal Pretreatment of Wood for Cogasification/cofiring of Biomass and Coal (open access)

Thermal Pretreatment of Wood for Cogasification/cofiring of Biomass and Coal

Utilization of biomass as a co-feed in coal and biomass co-firing and co-gasification requires size reduction of the biomass. Reducing biomass to below 0.2 mm without pretreatment is difficult and costly because biomass is fibrous and compressible. Torrefaction is a promising thermal pretreatment process and has the advantages of increasing energy density, improving grindability, producing fuels with more homogenous compositions and hydrophobic behavior. Temperature is the most important factor for the torrefaction process. Biomass grindability is related to cell wall structure, thickness and composition. Thermal treatment such as torrefaction can cause chemical changes that significantly affect the strength of biomass. The objectives of this study are to understand the mechanism by which torrefaction improves the grindability of biomass and discuss suitable temperatures for thermal pretreatment for co-gasification/cofiring of biomass and coal. Wild cherry wood was selected as the model for this study. Samples were prepared by sawing a single tangential section from the heartwood and cutting it into eleven pieces. The samples were consecutively heated at 220, 260, 300, 350, 450 and 550oC for 0.5 hr under flowing nitrogen in a tube furnace. Untreated and treated samples were characterized for physical properties (color, dimensions and weight), microstructural changes by SEM, …
Date: October 29, 2013
Creator: Wang, Ping; Howard, Bret; Hedges, Sheila; Morreale, Bryan; Van Essendelft, Dirk & Berry, David
Object Type: Report
System: The UNT Digital Library
Reed-Solomon error-correction as a software patch mechanism. (open access)

Reed-Solomon error-correction as a software patch mechanism.

This report explores how error-correction data generated by a Reed-Solomon code may be used as a mechanism to apply changes to an existing installed codebase. Using the Reed-Solomon code to generate error-correction data for a changed or updated codebase will allow the error-correction data to be applied to an existing codebase to both validate and introduce changes or updates from some upstream source to the existing installed codebase.
Date: November 1, 2013
Creator: Pendley, Kevin D.
Object Type: Report
System: The UNT Digital Library
JLIFE: THE JEFFERSON LAB INTERACTIVE FRONT END FOR THE OPTICAL PROPAGATION CODE (open access)

JLIFE: THE JEFFERSON LAB INTERACTIVE FRONT END FOR THE OPTICAL PROPAGATION CODE

We present details on a graphical interface for the open source software program Optical Propagation Code, or OPC. This interface, written in Java, allows a user with no knowledge of OPC to create an optical system, with lenses, mirrors, apertures, etc. and the appropriate drifts between them. The Java code creates the appropriate Perl script that serves as the input for OPC. The mode profile is then output at each optical element. The display can be either an intensity profile along the x axis, or as an isometric 3D plot which can be tilted and rotated. These profiles can be saved. Examples of the input and output will be presented.
Date: August 1, 2013
Creator: Watson, Anne M. & Shinn, Michelle D.
Object Type: Article
System: The UNT Digital Library
Test report : Raytheon / KTech RK30 energy storage system. (open access)

Test report : Raytheon / KTech RK30 energy storage system.

The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratories (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprising of lead acid, lithium-ion or zinc-bromide. Raytheon/KTech has developed an energy storage system that utilizes zinc-bromide flow batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the Raytheon/KTech Zinc-Bromide Energy Storage System.
Date: October 1, 2013
Creator: Rose, David Martin; Schenkman, Benjamin L. & Borneo, Daniel R.
Object Type: Report
System: The UNT Digital Library
Statistical Methods and Tools for Hanford Staged Feed Tank Sampling (open access)

Statistical Methods and Tools for Hanford Staged Feed Tank Sampling

This report summarizes work conducted by Pacific Northwest National Laboratory to technically evaluate the current approach to staged feed sampling of high-level waste (HLW) sludge to meet waste acceptance criteria (WAC) for transfer from tank farms to the Hanford Waste Treatment and Immobilization Plant (WTP). The current sampling and analysis approach is detailed in the document titled Initial Data Quality Objectives for WTP Feed Acceptance Criteria, 24590-WTP-RPT-MGT-11-014, Revision 0 (Arakali et al. 2011). The goal of this current work is to evaluate and provide recommendations to support a defensible, technical and statistical basis for the staged feed sampling approach that meets WAC data quality objectives (DQOs).
Date: October 1, 2013
Creator: Fountain, Matthew S.; Brigantic, Robert T. & Peterson, Reid A.
Object Type: Report
System: The UNT Digital Library
Construction Cost Estimate Livermore Site Solar Generation Project (open access)

Construction Cost Estimate Livermore Site Solar Generation Project

None
Date: October 8, 2013
Creator: Quinly, C E
Object Type: Report
System: The UNT Digital Library
Geometry Effects on Multipole Components and Beam Optics in High-Velocity Multi-Spoke Cavities (open access)

Geometry Effects on Multipole Components and Beam Optics in High-Velocity Multi-Spoke Cavities

Velocity-of-light, multi-spoke cavities are being proposed to accelerate electrons in a compact light-source. There are strict requirements on the beam quality which require that the linac have only small non-uniformities in the accelerating field. Beam dynamics simulations have uncovered varying levels of focusing and defocusing in the proposed cavities, which is dependent on the geometry of the spoke in the vicinity of the beam path. Here we present results for the influence different spoke geometries have on the multipole components of the accelerating field and how these components, in turn, impact the simulated beam properties.
Date: December 1, 2013
Creator: Hopper, Christopher S.; Deitrick, Kirsten E. & Delayen, Jean R.
Object Type: Article
System: The UNT Digital Library
Nuclear Fuel Cycle Reasoner: PNNL FY12 Report (open access)

Nuclear Fuel Cycle Reasoner: PNNL FY12 Report

Building on previous internal investments and leveraging ongoing advancements in semantic technologies, PNNL implemented a formal reasoning framework and applied it to a specific challenge in nuclear nonproliferation. The Semantic Nonproliferation Analysis Platform (SNAP) was developed as a preliminary graphical user interface to demonstrate the potential power of the underlying semantic technologies to analyze and explore facts and relationships relating to the nuclear fuel cycle (NFC). In developing this proof of concept prototype, the utility and relevancy of semantic technologies to the Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D) has been better understood.
Date: May 3, 2013
Creator: Hohimer, Ryan E.; Pomiak, Yekaterina G.; Neorr, Peter A.; Gastelum, Zoe N. & Strasburg, Jana D.
Object Type: Report
System: The UNT Digital Library
Package Management Practices Essential for Interoperability: Lessons Learned and Strategies Developed for FASTMath (open access)

Package Management Practices Essential for Interoperability: Lessons Learned and Strategies Developed for FASTMath

None
Date: September 3, 2013
Creator: Miller, M C; Diachin, L; Balay, S; McInnes, L C & Smith, B
Object Type: Article
System: The UNT Digital Library
A parametric study of BCS RF surface impedance with magnetic field using the Xiao Code (open access)

A parametric study of BCS RF surface impedance with magnetic field using the Xiao Code

N/A
Date: September 23, 2013
Creator: E., Reece C. & B., Xiao
Object Type: Article
System: The UNT Digital Library
EMPIRE: A code for nuclear astrophysics (open access)

EMPIRE: A code for nuclear astrophysics

N/A
Date: December 11, 2013
Creator: Palumbo, A.
Object Type: Report
System: The UNT Digital Library
High Efficiency Integrated Package (open access)

High Efficiency Integrated Package

Solid-state lighting based on LEDs has emerged as a superior alternative to inefficient conventional lighting, particularly incandescent. LED lighting can lead to 80 percent energy savings; can last 50,000 hours – 2-50 times longer than most bulbs; and contains no toxic lead or mercury. However, to enable mass adoption, particularly at the consumer level, the cost of LED luminaires must be reduced by an order of magnitude while achieving superior efficiency, light quality and lifetime. To become viable, energy-efficient replacement solutions must deliver system efficacies of ≥ 100 lumens per watt (LPW) with excellent color rendering (CRI > 85) at a cost that enables payback cycles of two years or less for commercial applications. This development will enable significant site energy savings as it targets commercial and retail lighting applications that are most sensitive to the lifetime operating costs with their extended operating hours per day. If costs are reduced substantially, dramatic energy savings can be realized by replacing incandescent lighting in the residential market as well. In light of these challenges, Cree proposed to develop a multi-chip integrated LED package with an output of > 1000 lumens of warm white light operating at an efficacy of at least 128 …
Date: September 15, 2013
Creator: Ibbetson, James
Object Type: Report
System: The UNT Digital Library
Technical Letter Report: Evaluation and Analysis of a Few International Periodic Safety Review Summary Reports (open access)

Technical Letter Report: Evaluation and Analysis of a Few International Periodic Safety Review Summary Reports

At the request of the United States (U.S.) government, the International Atomic Energy Agency (IAEA) assembled a team of 20 senior safety experts to review the regulatory framework for the safety of operating nuclear power plants in the United States. This review focused on the effectiveness of the regulatory functions implemented by the NRC and on its commitment to nuclear safety and continuous improvement. One suggestion resulting from that review was that the U.S. Nuclear Regulatory Commission (NRC) incorporate lessons learned from periodic safety reviews (PSRs) performed in other countries as an input to the NRC’s assessment processes. In the U.S., commercial nuclear power plants (NPPs) are granted an initial 40-year operating license, which may be renewed for additional 20-year periods, subject to complying with regulatory requirements. The NRC has established a framework through its inspection, and operational experience processes to ensure the safe operation of licensed nuclear facilities on an ongoing basis. In contrast, most other countries do not impose a specific time limit on the operating licenses for NPPs, they instead require that the utility operating the plant perform PSRs, typically at approximately 10-year intervals, to assure continued safe operation until the next assessment. The staff contracted with …
Date: December 17, 2013
Creator: Chopra, Omesh K.; Diercks, Dwight R.; Ma, David Chia-Chiun & Garud, Yogendra S.
Object Type: Report
System: The UNT Digital Library
Efficient Regeneration of Physical and Chemical Solvents for CO{sub 2} Capture (open access)

Efficient Regeneration of Physical and Chemical Solvents for CO{sub 2} Capture

The objective of this project was to evaluate the use of composite polymer membranes and porous membrane contactors to regenerate physical and chemical solvents for capture of carbon dioxide (CO{sub 2}) from synthesis gas or flue gas, with the goal of improving the energy efficiency of carbon capture. Both a chemical solvent (typical for a post-combustion capture of CO{sub 2} from flue gas) and a physical solvent (typical for pre- combustion capture of CO{sub 2} from syngas) were evaluated using two bench-scale test systems constructed for this project. For chemical solvents, polytetrafluoroethylene and polypropylene membranes were found to be able to strip CO{sub 2} from a monoethanolamine (MEA) solution with high selectivity without significant degradation of the material. As expected, the regeneration temperature was the most significant parameter affecting the CO{sub 2} flux through the membrane. Pore size was also found to be important, as pores larger than 5 microns lead to excessive pore wetting. For physical solvents, polydimethyl-siloxane (PDMS)-based membranes were found to have a higher CO{sub 2} permeability than polyvinylalcohol (PVOH) based membranes, while also minimizing solvent loss. Overall, however, the recovery of CO{sub 2} in these systems is low – less than 2% for both chemical and …
Date: May 31, 2013
Creator: Tande, Brian; Seames, Wayne & Benson, Steve
Object Type: Report
System: The UNT Digital Library
Towards an optical potential for rare-earths through coupled channels (open access)

Towards an optical potential for rare-earths through coupled channels

N/A
Date: September 1, 2013
Creator: Nobre, G. P. A.; Dietrich, F. S.; Herman, M.; Hoblit, S. & Brown, D.
Object Type: Article
System: The UNT Digital Library
Halide, Chromate, and Phosphate Impacts on LAW Glass for Dynamic Flowsheet 24590-WTP-MCR-PET-09-0037, Rev. 1 (open access)

Halide, Chromate, and Phosphate Impacts on LAW Glass for Dynamic Flowsheet 24590-WTP-MCR-PET-09-0037, Rev. 1

Revision 1 of this Model Change Request changed Equation 6 in Attachment Al only. Melter studies have shown that halide, chromium, and phosphates can cause precipitation of solids that can interfer the melting process. Pilot melter data now shows what concentrations LAW glass can tolerate. These limits shall be incorporated into the existing LAW glass algorithm per Attachment Al.
Date: December 16, 2013
Creator: Gimpel, Rodney F. & Kruger, Albert A.
Object Type: Report
System: The UNT Digital Library