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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,801 records · Page 100
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Synchrotron Investigations of SOFC Cathode Degradation

The atomic variations occurring in cathode/electrolyte interface regions of La 1-x Sr x Co y Fe 1-y O 3-δ (LSCF) cathodes and other SOFC related materials have been investigated and characterized using soft X-ray Absorption Spectroscopy (XAS) and diffuse soft X-ray Resonant Scattering (XRS). X-ray Absorption Spectroscopy in the soft X-ray region (soft XAS) is shown to be a sensitive technique to quantify the disruption that occurs and can be used to suggest a concrete mechanism for the degradation. For LSC, LSF, and LSCF films, a significant degradation mechanism is shown to be Sr out-diffusion. By using the XAS spectra of hexavalent Cr in SrCrO 4 and trivalent Cr in Cr 2 O 3 , the driving factor for Sr segregation was identified to be the oxygen vacancy concentration at the anode and cathode side of of symmetric LSCF/GDC/LSCF heterostructures. This is direct evidence of vacancy induced cation diffusion and is shown to be a significant indicator of cathode/electrolyte interfacial degradation. X-ray absorption spectroscopy is used to identify the occupation of the A-sites and B-sites for LSC, LSF, and LSCF cathodes doped with other transition metals, including doping induced migration of Sr to the anti-site for Sr, a significant cathode degradation indicator. By using spatially resolved valence mapping of Co, a complete picture of the surface electrochemistry can be determined. This is especially important in identifying degradation phenomena where the degradation is spatially localized to the extremities of the electrochemistry and not the average. For samples that have electrochemical parameters that are measured to be spatially uniform, the Co valence modifications were correlated to the effects of current density, overpotential, and humidity.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2014

Blender Pump Fuel Survey: CRC Project E-95-2

With the increasing fuel diversity in the marketplace, the Coordinating Research Council and the U.S. Department of Energy's National Renewable Energy Laboratory conducted a survey of mid-level ethanol blends (MLEBs) in the market. A total of 73 fuel samples were collected from 20 retail stations. To target Class 4 volatility, the fuel samples were collected primarily in the midwestern United States in the month of February. Samples included the gasoline (E0), Flex Fuel, and every MLEB that was offered from each of the 20 stations. Photographs of each station were taken at the time of sample collection, detailing the pump labeling and configuration. The style and labeling of the pump, hose, and dispenser nozzle are all important features to prevent misfueling events. The physical location of the MLEB product relative to the gasoline product can also be important to prevent misfueling. In general, there were many differences in the style and labeling of the blender pumps surveyed in this study. All samples were analyzed for volatility and ethanol content. For the MLEB samples collected, the fuels tended to be lower in ethanol content than their indicated amount; however, the samples were all within 10 vol% of their indicated blend level. One of the 20 Flex Fuel samples was outside of the allowable limits for ethanol content. Four of the 20 Flex Fuel samples had volatility below the minimum requirement for Class 4.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2013

Performance Degradation of LSCF Cathodes

This final report summarizes the progress made during the October 1, 2008 - September 30, 2013 period under Cooperative Agreement DE-NT0004109 for the U. S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled “Performance Degradation of LSCF Cathodes”. The primary objective of this program is to develop a performance degradation mitigation path for high performing, cost-effective solid oxide fuel cells (SOFCs). Strategies to mitigate performance degradation are developed and implemented. In addition, thermal spray manufacturing of SOFCs is explored. Combined, this work establishes a basis for cost-effective SOFC cells.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2014

The Methanol Economy Project

The Methanol Economy Project is based on the concept of replacing fossil fuels with methanol generated either from renewable resources or abundant natural (shale) gas. The full methanol cycle was investigated in this project, from production of methanol through bromination of methane, bireforming of methane to syngas, CO 2 capture using supported amines, co-electrolysis of CO 2 and water to formate and syngas, decomposition of formate to CO 2 and H 2 , and use of formic acid in a direct formic acid fuel cell. Each of these projects achieved milestones and provided new insights into their respective fields.

03 NATURAL GAS↗
DOE OSTI2014

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results: Third Report

This report presents results of a demonstration of 12 fuel cell electric buses (FCEB) operating in Oakland, California. The 12 FCEBs operate as a part of the Zero Emission Bay Area (ZEBA) Demonstration, which also includes two new hydrogen fueling stations. This effort is the largest FCEB demonstration in the United States and involves five participating transit agencies. The ZEBA partners are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service. NREL has published two previous reports, in August 2011 and July 2012, describing operation of these buses. New results in this report provide an update covering eight months through October 2013.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2014

Early Fuel Cell Market Deployments: ARRA and Combined (IAA, DLA, ARRA): Quarter 4 2013 Composite Data Products [Slides]

This report includes the composite data products (CDPs) for early fuel cell market deployments in quarter 4 of 2013. Results are presented for ARRA (projects funded by the American Recovery and Reinvestment Act of 2009 [ARRA]) and Combined (projects funded by DOE Interagency Agreements [IAA], Department of Defense Defense Logistics Agency [DLA], and ARRA).

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2014

NREL Works to Increase Electric Vehicle Efficiency Through Enhanced Thermal Management [Fact Sheet]

Researchers at NREL are providing new insight into how heating and cooling systems affect the distance that electric vehicles can travel on a single charge. Electric vehicle range can be reduced by as much as 68% per charge because of climate-control demands. NREL engineers are investigating opportunities to change this dynamic and increase driving range by improving vehicle thermal management. NREL experts are collaborating with automotive industry partners to investigate promising thermal management technologies and strategies, including zone-based cabin temperature controls, advanced heating and air conditioning controls, seat-based climate controls, vehicle thermal preconditioning, and thermal load reduction technologies.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2014

Impact of Generator Flexibility on Electric System Costs and Integration of Renewable Energy

Flexibility of traditional generators plays an important role in accommodating the increased variability and uncertainty of wind and solar on the electric power system. Increased flexibility can be achieved with changes to operational practices or upgrades to existing generation. One challenge is in understanding the value of increasing flexibility, and how this value may change given higher levels of variable generation. This study uses a commercial production cost model to measure the impact of generator flexibility on the integration of wind and solar generators. We use a system that is based on two balancing areas in the Western United States with a range of wind and solar penetrations between 15% and 60%, where instantaneous penetration of wind and solar is limited to 80%.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2014

Renewable Hydrogen Potential from Biogas in the United States

This analysis updates and expands upon previous biogas studies to include total potential and net availability of methane in raw biogas with respect to competing demands and includes a resource assessment of four sources of biogas: (1) wastewater treatment plants, including domestic and a new assessment of industrial sources; (2) landfills; (3) animal manure; and (4) a new assessment of industrial, institutional, and commercial sources. The results of the biogas resource assessment are used to estimate the potential production of renewable hydrogen from biogas as well as the fuel cell electric vehicles that the produced hydrogen might support.

08 HYDROGEN↗
DOE OSTI2014

Healthcare Energy End-Use Monitoring

NREL partnered with two hospitals (MGH and SUNY UMU) to collect data on the energy used for multiple thermal and electrical end-use categories, including preheat, heating, and reheat; humidification; service water heating; cooling; fans; pumps; lighting; and select plug and process loads. Additional data from medical office buildings were provided for an analysis focused on plug loads. Facility managers, energy managers, and engineers in the healthcare sector will be able to use these results to more effectively prioritize and refine the scope of investments in new metering and energy audits.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2014

Membrane-Organized Chemical Photoredox Systems

This project has three interrelated goals relevant to solar water photolysis, which are to develop: (1) vesicle-organized assemblies for H 2 photoproduction that utilize pyrylium and structurally related compounds as combined photosensitizers and cyclic electroneutral transmembrane electron carriers; (2) transmembrane redox systems whose reaction rates can be modulated by light; and (3) homogeneous catalysts for water oxidation. In area (1), initial efforts to photogenerate H 2 from vectorially-organized vesicles containing occluded colloidal Pt and commonly available pyrylium ions as transmembrane redox mediators were unsuccessful. New pyrylium compounds with significantly lower reduction potentials have been synthesized to address this problem, their apparent redox potentials in functioning systems have been now evaluated by using a series of occluded viologens, and H 2 photoproduction has been demonstrated in continuous illumination experiments. In area (2), spirooxazine-quinone dyads have been synthesized and their capacity to function as redox mediators across bilayer membranes has been evaluated through continuous photolysis and transient spectrophotometric measurements. Photoisomerization of the spiro moiety to the ring-open mero form caused net quantum yields to decrease significantly, providing a basis for photoregulation of transmembrane redox. Research on water oxidation (area 3) has been directed at understanding mechanisms of catalysis by cis,cis-[(bpy) 2 Ru(OH 2 )] 2 O 4+ and related polyimine complexes. Using a variety of physical techniques, we have: (i) identified the redox state of the complex ion that is catalytically active; (ii) shown using 18 O isotopic labeling that there are two reaction pathways, both of which involve participation of solvent H 2 O; and (iii) detected and characterized by EPR and resonance Raman spectroscopies new species which may be key intermediates in the catalytic cycle.

14 SOLAR ENERGY↗
DOE OSTI2014

BC Transit Fuel Cell Bus Project Evaluation Results: Second Report

Second report evaluating a fuel cell electric bus (FCEB) demonstration led by British Columbia Transit (BC Transit) in Whistler, Canada. BC Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's National Renewable Energy Laboratory to evaluate the buses in revenue service. NREL published its first report on the demonstration in February 2014. This report is an update to the previous report; it covers 3 full years of revenue service data on the buses from April 2011 through March 2014 and focuses on the final experiences and lessons learned.

08 HYDROGEN↗

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