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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Development of ITM Oxygen Technology for Low-cost and Low-emission Gasification and Other Industrial Applications

Air Products carried out a scope of work under DOE Award No. DE-FE0012065 “Development of ITM Oxygen Technology for Low-cost and Low-emission Gasification and Other Industrial Applications” with subcontractors Ceramatec, Penn State, and WorleyParsons. The scope of work under this award was aimed at furthering the development of the Ion Transport Membrane (ITM) Oxygen production process toward a demonstration-scale facility known as the Oxygen Development Facility (ODF). Specific activities will help to enable design and construction of the ODF through advancement of a number of challenging technical elements that are required to manage risk in the initial deployment of ITM technology. Major objectives of the work included developing ITM Oxygen ceramic membrane materials with improved performance and reliability, optimizing ceramic module geometry and fabrication methods, testing module performance, trialing the improved fabrication process at commercial scale in the Ceramic Membrane Module Fabrication Facility (CerFab), and advancing engineering development of the ITM oxygen production process, including vessel design and contaminant control measures to prepare for deployment of the ODF. The comprehensive report that follows details the team’s work, which includes several notable accomplishments: 1) compressive creep, a likely limiter of ceramic module lifetime in service, was demonstrated to be retarded by an order of magnitude by changes in material formulation, module joining dimensions, and internal wafer geometry; 2) two promising new materials were shown to be superior to the incumbent ITM material in a key material parameter related to oxygen flux; 3) module degradation mechanisms were identified following operation in large pilot-scale equipment; 4) options for utilizing ITM in a coal-to-liquids (CTL) facility to enable liquids production with carbon capture were identified and studied; and 5) the benefits of potential improvements to the technology were assessed for their cost impact on ITM Oxygen applications to clean power, fuels, and other applications.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2015

Development of ITM Oxygen Technology for Low-cost and Low-emission Gasification and Other Industrial Applications

Air Products carried out a scope of work under DOE Award No. DE-FE0012065 “Development of ITM Oxygen Technology for Low-cost and Low-emission Gasification and Other Industrial Applications” with subcontractors Ceramatec, Penn State, and WorleyParsons. The scope of work under this award was aimed at furthering the development of the Ion Transport Membrane (ITM) Oxygen production process toward a demonstration-scale facility known as the Oxygen Development Facility (ODF). Specific activities will help to enable design and construction of the ODF through advancement of a number of challenging technical elements that are required to manage risk in the initial deployment of ITM technology. Major objectives of the work included developing ITM Oxygen ceramic membrane materials with improved performance and reliability, optimizing ceramic module geometry and fabrication methods, testing module performance, trialing the improved fabrication process at commercial scale in the Ceramic Membrane Module Fabrication Facility (CerFab), and advancing engineering development of the ITM oxygen production process, including vessel design and contaminant control measures to prepare for deployment of the ODF. The comprehensive report that follows details the team’s work, which includes several notable accomplishments: 1) compressive creep, a likely limiter of ceramic module lifetime in service, was demonstrated to be retarded by an order of magnitude by changes in material formulation, module joining dimensions, and internal wafer geometry; 2) two promising new materials were shown to be superior to the incumbent ITM material in a key material parameter related to oxygen flux; 3) module degradation mechanisms were identified following operation in large pilot-scale equipment; 4) options for utilizing ITM in a coal-to-liquids (CTL) facility to enable liquids production with carbon capture were identified and studied; and 5) the benefits of potential improvements to the technology were assessed for their cost impact on ITM Oxygen applications to clean power, fuels, and other applications.

42 ENGINEERING↗
DOE OSTI2019

Improvements to Bison Validation Base for LWR Fuel

The Bison fuel performance code is being developed by Idaho National Laboratory (INL) to analyze a wide range of fuel forms and operating conditions with the flexibility to conduct simulations in 1D through 3D geometries. Bison plays an important role in the development of advanced fuel with improved accident tolerance for existing light water reactors (LWRs), the improved understanding of mechanisms in fuel designs in a wider range of operating conditions, and the facilitation of future development of fuel for advanced reactor designs. Additionally, industry interest in advanced fuels has also driven Bison development for advanced fuels in the last few years. All of these factors combine to create a potential increase of new Bison users. These new users will potentially be interested in the Bison LWR validation base for examples of Bison's capabilities and how to use Bison. Current users also rely on the Bison validation base as a demonstration of the best practices settings and material behavioral models. Bison, both through direct updates to the Bison source code and to the nearly daily changes and improvements in the underlying MOOSE framework source code, undergoes nearly continuous changes. It is necessary that these source code changes are reflected with updated input files in the Bison validation base. Periodic updates of the validation case input files should also be accompanied by a review and revision of the validation case documentation on which our users rely. Therefore our efforts under this milestone were guided by two objectives: (1) Update the Bison LWR validation input files to use current Bison simulation settings, and (2) Enhance the ease-of-use for Bison through improved documentation These objectives build on the goals identified FY18 CASL milestone reports. During FY18 we addressed issues with the robustness of Bison and identified a need to migrate the assessment suite to the more reliable tensor mechanics module system and set a goal of standardizing the Bison input files. The FY18 CASL milestone report on updates to the Bison documentation system listed continued development of user-focused guides and examples along with revisions to the validation case documentation as future development goals. During FY19 we have separated these two objectives into four different focus areas for our work on this milestone. Our first two focus areas target the existing Bison validation suite: update the existing LWR validation cases and the accompanying documentation. The second two focus areas center on adding new capabilities: a new Bison LWR validation case and expansion of user support documentation. In the following report each of these four focus areas are discussed as a separate section. We conclude the report with a summary of potential future work to build on the efforts of this year.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2026

Optimizing Repowering and Lifecycle Decisions with PV ICE and SAM

Should you repower or extend the life of your PV system? Are high-efficiency modules, durable modules, or recyclable modules the best option for your site and goals? Evaluating the trade-offs in design and lifecycle strategies can be complex. The PV in Circular Economy (PV ICE) tool is an open-source model designed to help developers, modelers, and decision-makers assess material flows, energy return on investment (EROI), and financial viability of PV systems. Now integrated with the System Advisor Model (SAM), PV ICE enables site-specific comparisons of lifecycle strategies - such as repowering benefits, module selection for reliability and recyclability, among others. This interactive tutorial will provide hands-on experience with PV ICE using Google Collab, exploring scenario-based analyses on these topics.

36 MATERIALS SCIENCE↗
NASA NTRS1976

Feasibility study of the design of Bi Ra Systems, Incorporated model 5301, 5101, and 3222 CAMAC modules for space use

Cost estimates are determined for redesigned modules. Consideration is given to incorporation of NASA approved components, component screening and documentation, as well as reduced power consumption. Results show that r designed modules will function reliably in a space environment of 50 C and withstand greater than 15 G's of random vibration between 40 Hz and 400 Hz.

Biswell, L.↗
NASA NTRS1981

Photovoltaic module hot spot durability design and test methods

As part of the Jet Propulsion Laboratory's Low-Cost Solar Array Project, the susceptibility of fat-plate modules to hot-spot problems is investigated. Hot-spot problems arise in modules when the cells become back-biased and operate in the negative-voltage quadrant, as a result of short-circuit current mismatch, cell cracking or shadowing. The details of a qualification test for determining the capability of modules of surviving field hot-spot problems and typical results of this test are presented. In addition, recommended circuit-design techniques for improving the module and array reliability with respect to hot-spot problems are presented.

Arnett, J. C.↗
NASA NTRS1995

Equalization and detection for digital communication over nonlinear bandlimited satellite communication channels

This dissertation evaluates receiver-based methods for mitigating the effects due to nonlinear bandlimited signal distortion present in high data rate satellite channels. The effects of the nonlinear bandlimited distortion is illustrated for digitally modulated signals. A lucid development of the low-pass Volterra discrete time model for a nonlinear communication channel is presented. In addition, finite-state machine models are explicitly developed for a nonlinear bandlimited satellite channel. A nonlinear fixed equalizer based on Volterra series has previously been studied for compensation of noiseless signal distortion due to a nonlinear satellite channel. This dissertation studies adaptive Volterra equalizers on a downlink-limited nonlinear bandlimited satellite channel. We employ as figure of merits performance in the mean-square error and probability of error senses. In addition, a receiver consisting of a fractionally-spaced equalizer (FSE) followed by a Volterra equalizer (FSE-Volterra) is found to give improvement beyond that gained by the Volterra equalizer. Significant probability of error performance improvement is found for multilevel modulation schemes. Also, it is found that probability of error improvement is more significant for modulation schemes, constant amplitude and multilevel, which require higher signal to noise ratios (i.e., higher modulation orders) for reliable operation. The maximum likelihood sequence detection (MLSD) receiver for a nonlinear satellite channel, a bank of matched filters followed by a Viterbi detector, serves as a probability of error lower bound for the Volterra and FSE-Volterra equalizers. However, this receiver has not been evaluated for a specific satellite channel. In this work, an MLSD receiver is evaluated for a specific downlink-limited satellite channel. Because of the bank of matched filters, the MLSD receiver may be high in complexity. Consequently, the probability of error performance of a more practical suboptimal MLSD receiver, requiring only a single receive filter, is evaluated.

Gutierrez, Alberto, Jr.↗
NASA NTRS2007

Lightweight, Flexible Solar Cells on Stainless Steel Foil and Polymer for Space and Stratospheric Applications

The availability of low-cost, lightweight and reliable photovoltaic (PV) modules is an important component in reducing the cost of satellites and spacecraft. In addition, future high-power spacecraft will require lightweight PV arrays with reduced stowage volume. In terms of the requirements for low mass, reduced stowage volume, and the harsh space environment, thin film amorphous silicon (a-Si) alloy cells have several advantages over other material technologies (1). The deposition process is relatively simple, inexpensive, and applicable to large area, lightweight, flexible substrates. The temperature coefficient has been found to be between -0.2 and -0.3 %/degC for high-efficiency triple-junction a-Si alloy cells, which is superior for high temperature operation compared to crystalline Si and triple-junction GaAs/InGaP/Ge devices at 0.53 %/degC and 0.45 %/degC, respectively (2). As a result, the reduction in efficiency at high temperature typical in space conditions is less for a-Si alloy cells than for their crystalline counterparts. Additionally, the a-Si alloy cells are relatively insensitive to electron and proton bombardment. We have shown that defects that are created by electrons with energies between 0.2 to 2 MeV with fluence up to 1x10(exp 15) e/sq cm and by protons with energy in the range 0.3 MeV to 5 MeV with fluence up to 1x10(exp 13) p/sq cm can be annealed out at 70 C in less than 50 hours (1). Further, modules incorporating United Solar s a-Si alloy cells have been tested on the MIR space station for 19 months with only minimal degradation (3). For stratospheric applications, such as the high altitude airship, the required PV arrays are typically of considerably higher power than current space arrays. Airships typically have a large area available for the PV, but weight is of critical importance. As a result, low cost and high specific power (W/kg) are key factors for airship PV arrays. Again, thin-film a-Si alloy solar cell technology is well suited to such applications.

Beernink, Kevin↗
DOE OSTI2015

Round-Robin Verification and Final Development of the IEC 62788-1-5 Encapsulation Size Change Test; NREL (National Renewable Energy Laboratory)

Polymeric encapsulation materials may a change size when processed at typical module lamination temperatures. The relief of residual strain, trapped during the manufacture of encapsulation sheet, can affect module performance and reliability. For example, displaced cells and interconnects threaten: cell fracture; broken interconnects (open circuits and ground faults); delamination at interfaces; and void formation. A standardized test for the characterization of change in linear dimensions of encapsulation sheet has been developed and verified. The IEC 62788-1-5 standard quantifies the maximum change in linear dimensions that may occur to allow for process control of size change. Developments incorporated into the Committee Draft (CD) of the standard as well as the assessment of the repeatability and reproducibility of the test method are described here. No pass/fail criteria are given in the standard, rather a repeatable protocol to quantify the change in dimension is provided to aid those working with encapsulation. The round-robin experiment described here identified that the repeatability and reproducibility of measurements is on the order of 1%. Recent refinements to the test procedure to improve repeatability and reproducibility include: the use of a convection oven to improve the thermal equilibration time constant and its uniformity; well-defined measurement locations reduce the effects of sampling size -and location- relative to the specimen edges; a standardized sand substrate may be readily obtained to reduce friction that would otherwise complicate the results; specimen sampling is defined, so that material is examined at known sites across the width and length of rolls; and encapsulation should be examined at the manufacturer’s recommended processing temperature, except when a cross-linking reaction may limit the size change. EVA, for example, should be examined 100 °C, between its melt transition (occurring up to 80 °C) and the onset of cross-linking (often at 100 °C).

14 SOLAR ENERGY↗
DOE OSTI2018

Finite Element Simulation of Mixed-Mode PV Encapsulant Delamination Based on Cohesive Zone Model: Preprint

A finite element model (FEM) was developed to simulate the mixed-mode delamination failure at the encapsulant interface within PV modules under mixed-mode loading condi- tions. Parameters to characterize the bilinear traction-separation constitutive behavior of cohesive elements were determined by testing the pure mode I critical fracture energy of the photovotaic(PV) cell interface using the width-tapered beam and fitting the simulated load-displacement curve with the tested curve. This developed FEM can be used to predict the critical temperature changes, at which delamination would initiate, of PV modules with different sizes and provide guidance for the design of PV module with better reliability.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2024

Avancando na Transicao Energetica: Desafios e Estrategias para a Implantacao Sustentavel de FV

As the world embarks on an ambitious journey towards global decarbonization, the spotlight turns to photovoltaic (PV) technology as a cornerstone for sustainable energy solutions. This talk delves into the current status and projections of PV for the World, US and Brasil, and the necessary considerations to do this increase in manufacturing and deployment sustainably. With the projected scale of deployment, the industry faces significant challenges related to material demand and the management of PV modules at their end of life. The principles of the Circular Economy (CE) and its associated R-Actions - Reduce, Reuse, Recycle, among others - present a promising framework to address these challenges by mitigating end-of-life management and material sourcing concerns. However, traditional CE metrics, often focused solely on mass, fall short by excluding vital energy flow considerations. In this talk, we will highlight how various metrics are needed to understand sustainable PV solutions, how continuing the search for increased efficiency can significantly reduce material demands and enhance energy metrics, while strategies around material circularity and module lifetime and reliability improvements will offer substantial reductions in both material and energy demands.

Brasil↗
DOE OSTI2014

Moving to a Higher Level for PV Reliability through Comprehensive Standards Based on Solid Science (Presentation)

PV reliability is a challenging topic because of the desired long life of PV modules, the diversity of use environments and the pressure on companies to rapidly reduce their costs. This presentation describes the challenges, examples of failure mechanisms that we know or don't know how to test for, and how a scientific approach is being used to establish international standards.

14 SOLAR ENERGY↗
DOE OSTI2021

Characterization of front contact degradation in monocrystalline and multicrystalline silicon photovoltaic modules following damp heat exposure

Reliability and durability tests play a key role in the photovoltaic (PV) industry by minimizing potential failure risks for both existing and new cell and module technologies. In this work, a detailed study of contact degradation in monocrystalline and multicrystalline PV modules is performed. The modules are subjected to a sequence of damp heat (DH) exposures followed by electrical characterization after each step. Electroluminescence (EL) imaging shows different darkening patterns for monocrystalline modules compared to multicrystalline modules; the former shows darkening near the busbars and the latter shows it across virtually the entire cell surface. The primary loss mechanism is confirmed to be resistive after comparing the current-voltage (I–V) characteristics at each DH exposure step. Representative samples have been cored out from both the degraded modules and controls for materials characterization to gain further insights into the degradation mechanism. Top-down and cross-sectional scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and top-down high-resolution X-ray photoelectron spectroscopy (XPS) analysis performed on the cored samples confirm the degradation is due to metallization corrosion. Our study suggests that the difference in the darkening pattern can most likely be attributed to the different silver paste composition used for contacting each cell technology, particularly the composition of the glass frit.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Flexible Thin-Film Silicon Solar Cells

High fuel costs, environmental concerns and issues of national energy security have brought increasing attention to a distributed generation program for electricity based on solar technology. Rooftop photovoltaic (PV) systems provide distributed generation since the power is consumed at the point of production, thus eliminating the need for costly additional transmission lines. However, most current photovoltaic modules are heavy and require a significant amount of labor and accessory hardware such as mounting frames for installation on rooftops. This makes rooftop systems impractical or cost prohibitive in many instances. Under this project, Xunlight has advanced its manufacturing process for the production of lightweight, flexible thin-film silicon based photovoltaic modules, and has enhanced the reliability and performance of Xunlight’s products. These modules are easily unrolled and adhered directly to standard commercial roofs without mounting structures or integrated directly into roofing membrane materials for the lowest possible installation costs on the market. Importantly, Xunlight has now established strategic alliances with roofing material manufacturers and other OEMs for the development of building integrated photovoltaic roofing and other PV-enabled products, and has deployed its products in a number of commercial installations with these business partners.

14 SOLAR ENERGY↗
DOE OSTI2024

Contactless Production Testing of Silicon Solar Cells

Critical cost reductions in silicon solar cells are made by minimizing silver usage in their metal contacts. The reason why is both clear and unavoidable—silver is not only expensive, but also a potential limiting resource for scale-up (the PV industry alone used 10.3 % of the global silver supply in 2020 [1]). The result is solar cells with vanishing electrical contact area that are extremely difficult to test prior to module manufacture, when they must be sorted for quality to maximize power output and reliability of the subsequent modules. This project developed a new measurement instrument that enables the transition to solar cells with very low silver content, including cell designs with both minimal busbars and no busbars at all to electrically contact. The resulting instrument at project completion demonstrated the ability to sort cells with comparable—or better—results than existing technology. Compared to existing cell-test instruments, the new tool has minimal contacting requirements, which lowers the maintenance costs and use of consumable parts. We demonstrated innovative, yet pragmatic, solutions for reporting a comprehensive set of measurement results useful for both cell sorting (going forward in the line for module manufacture) and process control (looking backward in the line to identify cell manufacturing issues from wafer to cell-test). In addition to the traditional current-voltage characterization at cell test—short circuit current, open-circuit voltage, power, efficiency and fill factor—the new tool maintains all the advanced parameter characterization of our existing product line such as a substrate doping measurement, carrier recombination (lifetime) analysis, and surface recombination analysis.

14 SOLAR ENERGY↗
NASA NTRS1992

Least Reliable Bits Coding (LRBC) for high data rate satellite communications

An analysis and discussion of a bandwidth efficient multi-level/multi-stage block coded modulation technique called Least Reliable Bits Coding (LRBC) is presented. LRBC uses simple multi-level component codes that provide increased error protection on increasingly unreliable modulated bits in order to maintain an overall high code rate that increases spectral efficiency. Further, soft-decision multi-stage decoding is used to make decisions on unprotected bits through corrections made on more protected bits. Using analytical expressions and tight performance bounds it is shown that LRBC can achieve increased spectral efficiency and maintain equivalent or better power efficiency compared to that of Binary Phase Shift Keying (BPSK). Bit error rates (BER) vs. channel bit energy with Additive White Gaussian Noise (AWGN) are given for a set of LRB Reed-Solomon (RS) encoded 8PSK modulation formats with an ensemble rate of 8/9. All formats exhibit a spectral efficiency of 2.67 = (log2(8))(8/9) information bps/Hz. Bit by bit coded and uncoded error probabilities with soft-decision information are determined. These are traded with with code rate to determine parameters that achieve good performance. The relative simplicity of Galois field algebra vs. the Viterbi algorithm and the availability of high speed commercial Very Large Scale Integration (VLSI) for block codes indicates that LRBC using block codes is a desirable method for high data rate implementations.

Vanderaar, Mark↗
DOE OSTI2018

Reliable and Low Cost Monolayer Backsheet for cSi Solar Modules

The main purpose of this project was to develop a low cost single layer white and clear polymeric backsheet material for use in silicon PV modules. The cost savings to end users would be impactful, as the PV component market strives to reduce costs while continuing to meet increasingly stringent reliability requirements and disposal concerns.The importance of developing a white backsheet that is cost-effective, recyclable, and reliable is evident in the current market; moreover, the increased availability and use of bifacial cells is bound to increase the demand for transparent backsheets in future markets as well. Today, the cost of a clear backsheet is significantly higher than a white backsheet which provides additional motivation for research and development of new material options in the PV backsheet field.

14 SOLAR ENERGY↗