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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 1,621 records · Page 90
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Oregon Offshore Wind Site Feasibility and Cost Study

The work performed in this Oregon study assessed the present and future costs of floating offshore wind technology deployment in the state of Oregon at commercial scale. It is widely recognized that floating offshore wind energy technology will be needed if significant offshore wind deployment in the Pacific region is to occur. The study was performed by the National Renewable Energy Laboratory (NREL) and its subcontractors and funded by the Bureau of Ocean Energy Management (BOEM). It was based, in part, on assumptions and analysis from an NREL report titled 'A Spatial-Economic Cost-Reduction Pathway Analysis for U.S. Offshore Wind Energy Development from 2015-2030' (Beiter et al. 2016), which supported the 'National Offshore Wind Strategy' (Gilman et al. 2016). The strategy builds on the previous DOE Wind Vision Study Scenario of 86 gigawatts (GW) of offshore wind deployed by 2050 in the United States. Under the Wind Vision scenario, 20% (17.2 GW installed capacity) of the nation's total offshore wind in 2050 comes from the Pacific coastal states (DOE 2015), which will require the development of floating wind technologies. Although most offshore development to date has been in depths of 50 meters (m) or less, 97% of Oregon's offshore wind resource is in water depths greater than 60 m, where floating wind is assumed to be needed. Floating offshore wind technology is still in its nascent stage of development but is advancing toward commercialization in both Europe and Asia. In this report, we use available floating prototype costs, pilot-scale costs, and commercial-scale costs from fixed-bottom offshore wind projects to model and analyze the cost of floating wind for five hypothetical wind sites in Oregon using specific geographical and utility grid information.

17 WIND ENERGY↗
NASA NTRS1980

FAME, a microprocessor based front-end analysis and modeling environment

Higher order software (HOS) is a methodology for the specification and verification of large scale, complex, real time systems. The HOS methodology was implemented as FAME (front end analysis and modeling environment), a microprocessor based system for interactively developing, analyzing, and displaying system models in a low cost user-friendly environment. The nature of the model is such that when completed it can be the basis for projection to a variety of forms such as structured design diagrams, Petri-nets, data flow diagrams, and PSL/PSA source code. The user's interface with the analyzer is easily recognized by any current user of a structured modeling approach; therefore extensive training is unnecessary. Furthermore, when all the system capabilities are used one can check on proper usage of data types, functions, and control structures thereby adding a new dimension to the design process that will lead to better and more easily verified software designs.

Rosenbaum, J. D.↗
NASA NTRSDate not supplied

Observations of Keyhole Porosity and Comparisons to Analytical Models for Ti-6Al-4V Powder Bed Fusion

Keyhole porosity defects are a common concern in powder bed fusion (PBF) processing. Keyhole porosity prediction models have generally fallen into two categories – high fidelity computational fluid dynamics simulations and low fidelity analytical or empirical models based on keyhole vibration dynamics. The low computational cost of low fidelity models allows them to better approach part-scale predictions. However, studies on low fidelity modeling techniques are limited by the lack of experimental data to assess the validity of the calibration over a wide range of processing conditions. This work extracts and quantifies keyhole porosity across 14 laser velocities, two laser powers, and six+ repetitions for a total of 176 independent trials. The measured porosity data are compared to low fidelity keyhole models to assess their success in predictive porosity occurrence. This work impacts the field by providing independent validation of keyhole porosity models for PBF for use in part-scale defect prediction.

powder bed fusion↗
DOE OSTI2021

Modeling of a 1/20th Scaled-down Gas Reactor Using MOOSE-based Application Pronghorn

University of Idaho (UI) designed and built a 1/20th scaled-down HTGR system to examine the mixing and venting of helium and reactor cavity air after a loss-of-coolant, also known as LOCA, due to a break in the reactor pressure vessel. Computational fluid dynamics (CFD) models of the system were developed, but their computational cost is high for modeling long transient accident scenarios. The objective of the project is to develop a simulation of the scaled-down system using the MOOSE-based application Pronghorn. A numerical approach is needed to have a better understanding of the physics phenomena that takes place following a LOCA event, and it can guide plant designers to design parameters for the development of mitigation techniques. This scenario is applicable to all HTR designs including the pebble bed reactor concept.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2024

Herbaceous Feedstock 2022 State of Technology Report

The U.S. Department of Energy promotes production of advanced liquid transportation fuels from lignocellulosic biomass by funding fundamental and applied research that advances the state of technology (SOT). As part of its involvement in this mission, Idaho National Laboratory completes an annual SOT report for nth-plant and 1st-plant herbaceous biomass feedstock logistics. The purpose of the SOT is to provide the status of feedstock supply system technology development for herbaceous biomass to biofuels relative to technical targets and cost goals from specific design cases, based on data and experimental results. Although conventional feedstock supply systems form the backbone of the emerging biofuels industry, they have limitations that restrict widespread implementation on a national scale. To meet the demands of the future industry, the feedstock supply system must shift from the conventional system to what has been termed “advanced” supply systems. In advanced designs, a distributed network of aggregation and processing centers, termed “depots,” are employed near the points of biomass production (i.e., the field or forest) to reduce feedstock variability and produce feedstocks of a uniform format, moving toward biomass commoditization. The 2022 Herbaceous SOT is part of a vision of achieving an implemented advanced feedstock supply system, which produces a stable, tradable commodity at the decentralized distributed depot. It utilizes feedstock fractionation by incorporating technologies that can separate the biomass into its anatomical fractions (leaves, husks, stems and cobs) to reduce impurities and produce fractions that satisfy downstream quality considerations. By using a series of air classification steps, this strategy can reduce the extrinsic ash in corn stover and produce enriched tissue fractions that can be blended to a conversion specification or converted individually in optimized biochemical conversion campaigns. Additionally, a majority of the leaves (which do not meet the quality specification) are separated out early and can be supplied to alternate markets. The 2022 Herbaceous SOT incorporates an advanced biomass fractionation and processing system to produce pellets enriched tissues from three-pass corn stover. The resulting enriched pellets are delivered to the biorefinery individually where they can be blended to a specification or converted in campaigns where the conditions are optimized for each tissue. Unused fractions can be sent to a a midstream market or to a different conversion process that is better suited to their properties to offset the cost of the delivered feedstock. The main benefits from the proposed system can be summarized as: (1) $6.86/dry ton (2016$) lower cost for the air classification due to elimination of the requirement to discard the high ash lights fraction; (2) $1.56/dry ton lower delivered cost by selling the unsuitable leaf fraction into the feed market as a midstream co-product (assuming a selling price that is 11% higher than their cost of production); (3) 0.98% increase in carbohydrate content (from 60.16% to 61.14%); and (4) 0.97% decrease in ash content (from 6.00% to 5.03%) compared to the 2021 Herbaceous SOT. Overall, the 2022 nth-plant Herbaceous SOT predicts a modeled delivered feedstock cost of $78.64/dry ton (2016$) if it is assumed that the enriched leaf fraction is sold at its production cost; this is a slight increase of $0.43/dry ton increase from the 2021 Herbaceous SOT nth-Supply case cost. The increased cost derived from a $0.38/dry ton increase in transportation and handling cost to procure more biomass (to replace the enriched leaf fraction that was not delivered to the biorefinery. The total preprocessing cost was $0.27/dry ton higher than the 2021 result because of updates to energy consumption, purchasing price and dry matter loss data for the rotary shear ($3.00/dry ton increase) and the pelleting mill ($4.52/dry ton increase). The data utilized were generated in pilot-scale tests in the Biomass Feedstock National User Facility (BFNUF) at INL and at Forest Concepts, including tests for rotary shear and pelleting of the air classified fractions. A greenhouse gas emissions analysis was performed by Argonne National Laboratory using the most up to date version of the Greenhouse Gases, Regulated Emissions, and Energy use in Transportation model (GREET®). The analysis showed an increase of 17.34 kg CO2e/dry ton from the 2021 SOT (67.71 kg CO2e/ton in the 2021 Herbaceous SOT to 85.05 kg CO2e/ton in the 2022 Herbaceous SOT). The net increase is primarily attributed to increased energy consumption in pelleting mill.

09 BIOMASS FUELS↗
NASA NTRS1977

New model framework and structure and the commonality evaluation model

The development of a framework and structure for shuttle era unmanned spacecraft projects and the development of a commonality evaluation model is documented. The methodology developed for model utilization in performing cost trades and comparative evaluations for commonality studies is discussed. The model framework consists of categories of activities associated with the spacecraft system's development process. The model structure describes the physical elements to be treated as separate identifiable entities. Cost estimating relationships for subsystem and program-level components were calculated.

Source record↗
DOE OSTI2022

Cost Update: Commercial and Advanced Heliostat Collectors

The research team performed a detailed bottom-up manufacturing cost estimate for 2 heliostat designs: i) a commercially available design, the Stellio; and ii) an advanced heliostat design, the Drop-C. The Drop-C is designed and developed by Solar Dynamics (SD) of the United States, whilst the Stellio has been developed primarily by Schlaich Bergermann Und Partner, Sonne Gmbh (sbp) of Germany. The Stellio heliostat has been deployed at commercial scale and is being used at the Hami CSP 50-megawatt electric (MW e ) power tower plant in China. For each design, this includes all components for manufacturing and assembly in a manufacturing facility (e.g., struts and frame) using Design for Manufacturing and Assembly (DFMA), and the purchased parts (e.g., mirrors, control systems, and drives). The field-assembly and construction activities are also considered to determine the installed cost of the modelled solar fields.

14 SOLAR ENERGY↗
DOE OSTI2014

Modular Undersea Compressed Air Energy Storage (UCAES) System

This project has been devoted to the design, optimization, and cost analysis of a unique power plant with integral energy storage. The proposed facility combines a novel underwater compressed air energy storage (UCAES) system with a customized gas turbine generator, providing exceptional power management and overall efficiency. Unlike conventional CAES, opportunities for underwater storage are plentiful and proximal to the power grid. The UCAES system provides coastal and island communities a practical means for managing the volatility of large-scale wind and solar power resources. The result is higher renewable energy absorption and improved electrical reliability with reduced fossil fuel consumption. The UCAES power plant is composed of three major subsystems: The underwater air containment system (ACS), the air transport pipe (ATP), and the land-based power conversion system (PCS). The underwater ACS is made up of modular concrete shell units, structurally optimized for minimal material usage while employing conventional production methods and equipment. Each shell is designed to receive and control loose fill or gravel, serving as the ballast. The static nature of the final structures make them an asset to marine habitats and includes features intended to permit safe and cost-effective deployment. The ATP Connects the ACS modules to each other and to the on-land power conversion system and utilizes high density polyethylene (HDPE) pipe for low cost and long life. The PCS Houses the turbine-generator ‘expander modules’, with peak capacity of 12.3 MWe each, engineered from existing gas turbine equipment and includes electrically driven commercial 3-stage intercooled centrifugal compressors, each nominally drawing 6.6 MWe when matching the turbine flow requirements. The subsystems listed above are designed with the intent to serve as building-blocks to achieve a peak power output rating in the 40 to 120 MWe range, with 0.25 to 4 hours of energy storage capacity. The modular facility with integral energy storage provides some remarkable transient maneuvers and load-following features unachievable by competing technologies. The system can operate as a dispatchable power plant with a fuel-to-electric efficiency over 41%; substantially better that the average existing Hawaiian peak power generation assets. Optimal efficiency can be maintained while load-following due to modular PCS design and is operable with a range of liquid or gaseous fuels while meeting the most stringent California (CARB) emission standards. The system can operate as a peaking energy plant in discharge mode. Power ramp-up equivalent to 215% of continuous load rating within 1 second accomplished by simply turning off the electric compressor(s). Contrarily, the system can offer energy absorption during periods of grid surplus generation. The electric compressors may be sequenced on to absorb power within seconds. More moderate transitions are easily achieved with standard compressor control functions. The system offers unique features as compared to energy storage systems. ‘Round-trip efficiency’, as calculated by industry standard methods, is in the 90% range. The PCS equipment has a mean-time between overhauls of 80,000 hours, with maintenance costs of less than $0.005/kW-hr of electricity delivered. The underwater ACS structures and piping employ materials and designs specified to achieve a 75 year life. With the underwater containment modules qualified as a marine habitat, there would be no decommissioning costs. In conjunction with the engineering work invested in the design of the UCAES power plant, Brayton Energy has employed a team of manufacturing specialists, marine construction engineers, and power industry experts to create a comprehensive economic model that captures the many site-related variables and configuration options. The cost results and methodology have been validated by suppliers, engineers, and deployment specialists through a detailed case study on Hawaii. While creation of the parametric cost model was based on inputs specific to Hawaii, the proposed construction and deployment steps were chosen to be general enough to allow extrapolation across locations world-wide. Analysis of the proposed system shows it to be a viable option and addresses the principal challenges described by the Department of Energy by offering competitive costs, validated safety and reliability, consideration of the regulatory environment, and utilization of industry accepted practices and equipment. The UCAES system is recommended for immediate consideration in Hawaii. Estimation of time to complete planning, design, and construction of the facility is anticipated to take 3 to 5 years. Other coastal and island communities world-wide should realize similar benefits; as the results presented in this report are considered generally transferable to other locations.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2024

Quantification of Hydrogen Isotopes Utilizing Raman Spectroscopy Paired with Chemometric Analysis for Application across Multiple Systems

On-line and real-time analysis of a chemical process is a major analytical challenge that can drastically change the way the chemical industry or chemical research operates. With in situ analyses, new and powerful understanding of chemistry can be gained; however, building robust tools for long-term monitoring faces many challenges that include compensating for instrument drift, instrument replacement, and sensor or probe replacement. Accounting for these changes by recollecting calibration data and rebuilding quantification models can be costly and time consuming. Here, in this study, methods to overcome these challenges are demonstrated with an application of Raman spectroscopy to monitoring hydrogen isotopes with varied speciation within dynamic gas streams. Specifically, chemical data science tools such as chemometric modeling are leveraged along with several examples of calibration transfer approaches. Furthermore, the optimization of instrument and sensors cell parameters for targeted gas phase analyses is discussed. While the particular focus on hydrogen is highly beneficial within the nuclear energy sector, mechanisms built and demonstrated here are widely applicable to optical spectroscopy monitoring in numerous other chemical systems that can be leveraged in other hazardous processes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Aquantis 2.5 MW Ocean Current Generation Device - Scaled Tank Test Design and Results

Aquantis 2.5 MW Ocean Current Generation Device, Tow Tank Dynamic Rig Structural Analysis Results. This is the detailed documentation for scaled device testing in a tow tank, including models, drawings, presentations, cost of energy analysis, and structural analysis. This dataset also includes specific information on drivetrain, roller bearing, blade fabrication, mooring, and rotor characteristics.

16 TIDAL AND WAVE POWER↗
DOE OSTI2016

Carbon cost of plant nitrogen acquisition: global carbon cycle impact from an improved plant nitrogen cycle in the Community Land Model

Abstract Plants typically expend a significant portion of their available carbon ( C ) on nutrient acquisition – C that could otherwise support growth. However, given that most global terrestrial biosphere models ( TBM s) do not include the C cost of nutrient acquisition, these models fail to represent current and future constraints to the land C sink. Here, we integrated a plant productivity‐optimized nutrient acquisition model – the Fixation and Uptake of Nitrogen Model – into one of the most widely used TBM s, the Community Land Model. Global plant nitrogen ( N ) uptake is dynamically simulated in the coupled model based on the C costs of N acquisition from mycorrhizal roots, nonmycorrhizal roots, N‐fixing microbes, and retranslocation (from senescing leaves). We find that at the global scale, plants spend 2.4 Pg C yr −1 to acquire 1.0 Pg N yr −1 , and that the C cost of N acquisition leads to a downregulation of global net primary production ( NPP ) by 13%. Mycorrhizal uptake represented the dominant pathway by which N is acquired, accounting for ~66% of the N uptake by plants. Notably, roots associating with arbuscular mycorrhizal ( AM ) fungi – generally considered for their role in phosphorus (P) acquisition – are estimated to be the primary source of global plant N uptake owing to the dominance of AM ‐associated plants in mid‐ and low‐latitude biomes. Overall, our coupled model improves the representations of NPP downregulation globally and generates spatially explicit patterns of belowground C allocation, soil N uptake, and N retranslocation at the global scale. Such model improvements are critical for predicting how plant responses to altered N availability (owing to N deposition, rising atmospheric CO 2 , and warming temperatures) may impact the land C sink.

Shi, Mingjie↗
DOE OSTI2025

Zigzag flow reactor for weekly thermochemical energy storage

This paper describes theoretical models and experimental performance of a novel Zigzag Flow Reactor (ZFR) for weekly thermochemical energy storage. The ZFR reduces redox-active metal oxide (MO x ) particles at high temperature (up to ~1100 °C) under inert gas sweep. A physical model demonstrates the approach to process equilibrium by minimizing the associated exergy destruction in a finite number of reaction steps, establishing the thermodynamic requirements for a practical reactor. The model results show several cost-relevant parameter tradeoffs, and the tradeoff analysis implies a cost-optimized set of boundary conditions. Numerical models and prototypes show that the ZFR enables significant gas phase homogenization while simultaneously enabling a customizable MO x residence time in the reactor, both key requirements for approaching an equilibrium process. A scaling model demonstrates the simplicity and affordability of sizing the ZFR to grid-scale levels, with fabrication costs at least five times lower than previously proposed scalable reactor concepts. As a result, a laboratory ZFR prototype achieved an energy storage density of ~90 Wh/kg with CaAl 0.2 Mn 0.8 O 3-δ as the MO x , at temperatures of ~850 °C in >10 h of total runtime.

Thermochemical energy storage↗
DOE OSTI2016

Optimization under Uncertainty of Site-Specific Turbine Configurations: Preprint

Uncertainty affects many aspects of wind energy plant performance and cost. In this study, we explore opportunities for site-specific turbine configuration optimization that accounts for uncertainty in the wind resource. As a demonstration, a simple empirical model for wind plant cost of energy is used in an optimization under uncertainty to examine how different risk appetites affect the optimal selection of a turbine configuration for sites of different wind resource profiles. If there is unusually high uncertainty in the site wind resource, the optimal turbine configuration diverges from the deterministic case and a generally more conservative design is obtained with increasing risk aversion on the part of the designer.

17 WIND ENERGY↗
DOE OSTI2021

Dynamically Collected Local Density using Low-Cost Lidar and its Application to Traffic Models

This article demonstrates the use of traffic density observations collected dynamically in the vicinity of probe vehicles. Fixed position sensors cannot capture the longitudinal evolution of local traffic density in the corridor. In this research, dynamic traffic density observations were collected in a naturalistic driving setting that was free of any controlled experiment biases. Speed from global positioning system and space headway from a light detection and ranging module was collected on one arterial and one freeway segment, 2 and 4mi long, respectively. The combined data frequency was approximately 3Hz. Space headway was used to estimate the local density and consequently to identify the density of a specific location in a corridor. Besides, driver behavior was characterized using the relationship between instantaneous speed and local density under different regimes of the Wiedemann car-following model. Macroscopic traffic stream models were used to investigate the relationship between dynamically collected instantaneous speed and local density. Using the longitudinal evolution of density, precise local density across the corridor can be obtained along with the leader and follower trajectories. A method to identify driver behavior across density ranges was developed for different facility types using a microscopic relationship between instantaneous speed and local density. Overall driving behavior on the freeway segment can be represented by translating the instantaneous speed and local density relationship to macroscopic stream models.

Engineering↗
DOE OSTI2013

Defect Engineering, Cell Processing, and Modeling for High-Performance, Low-Cost Crystalline Silicon Photovoltaics

The objective of this project is to close the efficiency gap between industrial multicrystalline silicon (mc-Si) and monocrystalline silicon solar cells, while preserving the economic advantage of low-cost, high-volume substrates inherent to mc-Si. Over the course of this project, we made significant progress toward this goal, as evidenced by the evolution in solar-cell efficiencies. While most of the benefits of university projects are diffuse in nature, several unique contributions can be traced to this project, including the development of novel characterization methods, defect-simulation tools, and novel solar-cell processing approaches mitigate the effects of iron impurities ("Impurities to Efficiency" simulator) and dislocations. In collaboration with our industrial partners, this project contributed to the development of cell processing recipes, specialty materials, and equipment that increased cell efficiencies overall (not just multicrystalline silicon). Additionally, several students and postdocs who were either partially or fully engaged in this project (as evidenced by the publication record) are currently in the PV industry, with others to follow.

14 SOLAR ENERGY↗
NASA NTRS1975

Shuttle user analysis (study 2.2). Volume 3: Business risk and value of operations in space (BRAVO). Part 5: Analysis of GSFC Earth Observation Satellite (EOS) system mission model using BRAVO techniques

Cost comparisons were made between three modes of operation (expend, ground refurbish, and space resupply) for the Earth Observation System (EOS-B) to furnish data to NASA on alternative ways to use the shuttle/EOS. Results of the analysis are presented in tabular form.

Source record↗
NASA NTRS1978

Structural design of a 64-meter low-cost antenna

The computer model of a 64 m ground antenna was generated by 1108 software. The reflector and alidade model was iteratively designed and analyzed by the JPL/IDEAS program, which minimized the distortion RMS with respect to the structural weight. Curves of values describing the optimizing processes are presented, functional aspects of the structural elements are defined, and detail descriptions of the design equations for stress calculations are included. Computed data used for calculating the RF boresight error and natural frequency answers are also included.

Katow, M. S.↗
NASA NTRS1978

The value of information as applied to the Landsat Follow-on benefit-cost analysis

An econometric model was run to compare the current forecasting system with a hypothetical (Landsat Follow-on) space-based system. The baseline current system was a hybrid of USDA SRS domestic forecasts and the best known foreign data. The space-based system improved upon the present Landsat by the higher spatial resolution capability of the thematic mapper. This satellite system is a major improvement for foreign forecasts but no better than SRS for domestic forecasts. The benefit analysis was concentrated on the use of Landsat Follow-on to forecast world wheat production. Results showed that it was possible to quantify the value of satellite information and that there are significant benefits in more timely and accurate crop condition information.

Wood, D. B.↗