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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 721 records · Page 40

Development and Validation of Low-Cost, High-Reflectance Composite CSP Facets: SIPS Final Report

This work investigates the various challenges associated with developing heliostat structural composite facets using 1 mm glass mirrors. Such facets are desirable for Concentrating Solar Power because 1 mm glass mirrors provide an absolute increase in reflectivity of 2-3 % over the industry standard of 4 mm glass mirrors. Prototypes of paraboloid composite facets with 1 mm glass mirrors were constructed that have a root mean square slope error on the order of 2 mrad while achieving greater than 96% reflectivity. These facets were constructed using a low-quality aluminum mold and a bill of materials that show potential to achieve cost parity with existing 4 mm glass mirrors supported by structural steel. The facets produced were able to survive up to 50 mm hail ball impacts and were robust against accelerated environmental cycling designed to expose durability concerns. Further work is needed to develop a scalable and cost-effective manufacturing process with a similar bill of materials.

14 SOLAR ENERGY↗

Tandem Photovoltaics Core Program Final Technical Report

The Tandem Photovoltaics Core Program was a multi-year initiative aimed at advancing hybrid tandem solar cell technologies to enhance solar module efficiency beyond the limits of single junction devices. This project focused on the development, testing, and scaling of prototype photovoltaic devices, with the goal of achieving commercial relevance and driving industry adoption. The work was divided into three tasks: 1) Comparative Analysis of Tandem Technologies: This task focused on quantifying energy yield under real-world conditions and assessing economic viability of tandems relative to silicon-based modules. The project's modeling framework incorporated performance data, cost of materials, and manufacturing process impacts to optimize tandem designs 2) Tandem Integration and Prototyping: In this task, we developed innovative tandem designs by combining metal halide perovskite (MHP) top cells and silicon (Si) bottom cells. The project focuses on both mechanical integration and direct deposition techniques to enable compatibility with commercially relevant Si technologies, such as passivated contact or PERC cells. 3) Scale-up and Reliability: This task addressed the challenges of large-area fabrication by developing scalable deposition methods and robust interconnection schemes for tandems. The project looked at different accelerated testing such as thermal cycling, damp heat exposure, and potential induced degradation, to ensure long-term stability of devices in field conditions. Tandem solar cells can greatly increase module efficiency beyond conventional single junction (SJ) devices, which are approaching their theoretical limit. There are many ways to fabricate a tandem cell or module in terms of materials used, configuration, and terminal connection. This SETO core project focused critical factors in enabling tandems to enter the market, including hardware integration, technoeconomic analysis (TEA), and energy yield analysis. We focused on MHP/Si hybrid tandem solar cells and modules as a model system for their versatility in module design comparisons, providing valuable insights for other tandem options. While champion cells with areas <1cm2 are regularly demonstrated by groups around the world, it is significantly more challenging to translate these advances into modules, and fewer institutions and companies are working at the module level. This project addressed questions about module fabrication, testing, and reliability that are hard to answer without actually fabricating prototypes. We also performed analysis and road-mapping activities to understand the potential for a wider variety of tandems, including all-perovskite tandems fabricated in collaboration with the Perovskite PV core program. Detailed technical results from this project are described for each task in Section 7.

14 SOLAR ENERGY↗

Heat treatment to anneal residual stresses during additive manufacturing

An additive manufacturing system having a heat source for melting powder particles in a desired shape and pattern to produce a product. A secondary heat source is used for heat treating the product to achieve heat treatment. The secondary heat source is used to peen or anneal residual stresses caused by the additive manufacturing process.

36 MATERIALS SCIENCE↗

Grain boundary engineering for additive manufacturing

In one embodiment, a method of manufacturing a metal part using a laser or electron beam during a powder bed additive manufacturing process includes melting each of a number of layers of metal powder of the metal part with an effective amount of energy using the laser or electron beam to form the metal part such that at least one or more portions of the metal part have a critical amount of residual strain. The method also includes performing a heat treatment on the metal part that transforms the residual strain into substantially distributed coincidence site lattice (CSL) grain boundaries, low angle grain boundaries, or both in the metal part.

36 MATERIALS SCIENCE↗

System and method for forming material substrate printer

A method is disclosed for manufacturing a part via an additive manufacturing process. A solution is used which has a volatile component within which is suspended particles of a powdered material. The solution is heated until it at least one of begins boiling or is about to begin boiling. The heated solution is then deposited at least at one location on a substrate to help form a layer of the part. The volatile component then evaporates, leaving only the particles of powdered material. The particles are then heated to the melting point. The deposition and heating operations are repeated to successively form a plurality of layers for the part. The evaporation of the volatile component helps to cool the part.

36 MATERIALS SCIENCE↗

Methods and apparatus for embedding heating circuits into articles made by additive manufacturing and articles made therefrom

Methods of embedding a heating circuit in an article fabricated by additive manufacturing. The methods describe techniques such as co-extruding a wire, capable of being heated, along with print material in additive manufacturing of the article, and placing a pre-shaped wire capable of being heated between adjacent layers of the article. A third method includes dispensing a wire, capable of being heated, during the additive manufacturing of the article, and compacting the wire into the printed material. An apparatus for embedding a heating circuit in an article fabricated by additive manufacturing. The apparatus contains a wire dispenser, a cutter to control the length of the wire dispensed, and a compactor capable of embedding the wire capable of being heated into the printed material. An article made by additive manufacturing is disclosed. The article contains at least one heating element embedded in the article during the additive manufacturing process.

Barocio, Eduardo↗

Accomplishments and Year-End Performance Report; Wind Energy Program: Fiscal Year 2021

The National Wind Technology Center (NWTC), located at the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL) Flatirons Campus, has been a driving force in advancing wind energy technology research worldwide since its designation as a DOE national research center in 1992. Enabled by the Flatirons Campus's world-class facilities, scientists, engineers, analysts, and researchers are pushing the frontiers of science to pursue wind energy innovation. In Fiscal Year (FY) 2021, NREL continued to provide the technical expertise, research capabilities, and industry understanding to support DOE's ambitious climate action and research goals by advancing technology, addressing market and deployment barriers, and driving down costs with more efficient, reliable, and predictable wind energy systems. One of several highlights, NREL received an R&D 100 Special Recognition Award for its Thermoplastic Resin System for Wind Turbine Blades. This breakthrough in the wind turbine manufacturing process will enable the production of recyclable blades that are stronger, longer, and less expensive, while increasing energy capture, decreasing energy and transportation costs, and increasing blade reliability. In a year when the entire U.S. economy struggled to address workforce gaps, an NREL study compared wind industry needs, training programs, and hiring practices with perspectives from students and recent college graduates. Researchers hope that, by pinpointing areas of disconnect, the expectations of employers who have difficulty filling entry-level jobs can better align with the preparation of the potential applicants who find it hard to break into the field. The lab also made numerous new data and modeling resources available in FY 2021. Recent NREL releases include a modeling tool for predicting the power performance and structural loads of wind turbines within a wind farm (FAST.Farm), a computational framework for modeling golden eagle behavior near wind farms, and 20 years of offshore wind data. Updates were also made to the widely used Wind Plant Integrated Systems Design and Engineering Model (WISDEM), which couples engineering and cost models to examine system-level trade-offs. Now, bolstered by a renewed national commitment to tackle climate change and revitalize the U.S. economy through increased investment in clean energy - particularly in offshore wind energy - NREL stands poised to lead the way to a sustainable future that powers the United States with significant levels of reliable, low-cost, accessible wind energy. This report provides an overview of the achievements NREL made on behalf of DOE's Wind Energy Technologies Office (WETO) and other partners during FY 2021 (between Oct. 1, 2020, and Sept. 30, 2021).

Flatirons Campus↗

Fully integrated multi-phase buck converter with coupled air core inductors

A multi-phase buck switching converter having grouped pairs of phases, each phase using two magnetically coupled air-core inductors. For each group, a first driver circuit controlling switching of a first power transistor switching circuit coupled to a first air-core inductor output for driving an output load at the first phase. A second driver circuit controlling switching of a second power transistor switching circuit coupled to a second air-core inductor output for driving said output load at the second phase. The first and second phases are spaced 180° apart. The coupled air-core inductors per group of such orientation, separation distance and mutual inductance polarity relative to each other such that magnetic coupling between the two or more inductors at each phase results in a net increase in effective inductance per unit volume. Each air-core inductor is a metal slab of defined length, height and thickness formed using back-end-of-line semiconductor manufacturing process.

Zhang, Xin↗

Piston with insulating air gap formed by additive manufacturing

The present disclosure provides a piston, comprising: a skirt having an upper body portion; and a crown formed on the upper body portion by an additive manufacturing process, the crown including at least one air gap formed and positioned to reduce heat transfer from combustion to at least one cooling gallery formed in the piston.

Kelleher, Jordan E.↗

GANISP: A GAN-Assisted Importance Splitting Probability Estimator

Designing manufacturing processes with high yield and strong reliability relies on effective methods for rare event estimation. Genealogical importance splitting reduces the variance of rare event probability estimators by iteratively selecting and replicating realizations that are headed towards a rare event. The replication step is difficult when applied to deterministic systems where the initial conditions of the offspring realizations need to be modified. Typically, a random perturbation is applied to the offspring to differentiate their trajectory from the parent realization. However, this random perturbation strategy may be effective for some systems while failing for others, preventing variance reduction in the probability estimate. This work seeks to address this limitation using a generative model such as a Generative Adversarial Network (GAN) to generate perturbations that are consistent with the attractor of the dynamical system. The proposed GAN-assisted Importance SPlitting method (GANISP) improves the variance reduction for the system targeted. An implementation of the method is available in a companion repository (https://github.com/NREL/GANISP).

generative adversarial network↗

2021 Prototype Installation and Testing Awardee: XFlow Energy Company

XFlow Energy Company (XFlow Energy) aims to reduce the cost of wind energy by designing vertical-axis wind turbines (VAWTs), which have a cheaper blade manufacturing process and a mechanically simpler design than traditional wind turbines, among other cost-saving advantages. However, a lack of modeling or simulation tools that can predict the coupling between aerodynamic and structural forces poses a significant challenge to developers of VAWTs. Known as aeroelastic models, these are not just important design tools - they're critical for certifying VAWTs of 25 kilowatts (kW), which is the size of XFlow Energy's prototype wind turbine. Without certification, XFlow Energy will not be able to deliver an independently validated product to its customers, and those customers will not be eligible for state and federal incentives. An accurate aeroelastic model could provide less-conservative structural optimization tactics than are currently used, resulting in a wind turbine with lower capital costs.

CIP↗

Optical Transmission Characterization of Fused Silica Materials Irradiated at the CERN Large Hadron Collider

The Target Absorbers for Neutrals (TANs) represent one of the most radioactive regions in the Large Hadron Collider (LHC). Seven 40 cm long fused silica rods with different dopant specifications, manufactured by Heraeus, were irradiated in one of the TANs located around the ATLAS experiment by the Beam RAte of Neutrals (BRAN) detector group. This campaign took place during the Run 2 p+p data taking, which occurred between 2016 and 2018. This paper reports a complete characterization of optical transmission per unit length of irradiated fused silica materials as a function of wavelength (240 nm - 1500 nm), dose (up to 18 MGy), and level of OH and H$_2$ dopants introduced in the manufacturing process. The dose delivered to the rods was estimated using Monte Carlo simulations performed by the CERN FLUKA team.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Impact of Nozzle Condition on Powder Catchment Efficiency for Coaxial Powder Direct Energy Deposition

Blown powder directed energy deposition is well-designed for fine resolution additive manufacturing processing. Coaxial powder deposition heads use an outer layer of shielding gas directed by an outer nozzle to prevent oxidation occurring during the powder melting process. Powder blown feedstock catchment efficiency can be as low as 50-80% whereas wire deposition systems are closer to 98% efficient. The present study evaluates the impact of directed energy deposition nozzle condition on catchment efficiency. Changes in the overall outer shielding gas nozzle length has been found to increase material usage efficiency by 10% through convergence of the powder flow. The results of this experiment show that for coaxial powder deposition head design, if the standoff distance can safely be decreased, powder catchment efficiency can be increased as the outer shielding gas nozzle is increased in length, or the standoff distance is decreased.

Heinrich, Lauren↗

System and method for forming material substrate printer

A method is disclosed for manufacturing a part via an additive manufacturing process. A solution is used which has a volatile component within which is suspended particles of a powdered material. The solution is heated until it at least one of begins boiling or is about to begin boiling. The heated solution is then deposited at least at one location on a substrate to help form a layer of the part. The volatile component then evaporates, leaving only the particles of powdered material. The particles are then heated to the melting point. The deposition and heating operations are repeated to successively form a plurality of layers for the part. The evaporation of the volatile component helps to cool the part.

Demuth, James A.↗

3D-printed electrode, gas diffusion electrode (GDE) and gas diffusion layer (GDL) for fuel cell applications

An electrocatalytically active ink composition is used with an additive manufacturing process, such as 3D printing, to produce electrodes having consistent, adaptable, and high surface area structures. The electrocatalytically active ink composition includes a mixed powdered precursor and a polymer matrix. The mixed powdered precursor includes a carbon source, a dopant source, and/or a metal-containing catalyst. The material and electrochemical properties of the ink composition may facilitate 3D printing of electrochemically active electrodes for energy conversion and storage devices, and may allow fine-tuning of macro- and microstructures to develop electrodes having improved activity and efficiency.

Lee, Kwan-Soo↗

North American Lithium-Ion Battery Supply Chain Database Development - Phase II

Lithium-ion batteries (LIBs) are used in a wide range of applications, including cell phones, laptops, power tools, electric vehicles, and grid storage, and are essential for economic growth and addressing climate change. However, the significant demand for LIBs has led to supply chain issues for the United States, as China dominates the processing of battery materials and battery production. To address this concern, NAATBatt International, a trade association of North American battery companies, supported the National Renewable Energy Laboratory in developing a database of companies that mine, process, manufacture, reuse, and recycle batteries in North America. The purpose of this database was to identify strengths and gaps in the supply chain, so that private-government partnerships could develop strategies to create a competitive LIB supply chain in the US. NREL published the first version of this database in 2021 and the second version in 2022. The database includes companies that have a manufacturing facility in North America and are engaged in materials, cells, packs, end-of-life management, as well as those involved in LIB battery modeling, distribution, service and repair, and R&D. In this presentation, we will discuss our approach to collecting data and categorizing various segments and products. We will also provide a summary of the data and present various maps to illustrate the distribution of companies in the database.

ADVANCED PROPULSION SYSTEMS,ENERGY STORAGE↗

Morphology Control of Growth by Hydride Vapor Phase Epitaxy on Faceted GaAs Substrates Produced by Controlled Spalling for Low Cost III-V Devices

In this work, we apply the morphology control of hydride vapor phase epitaxial (HVPE) growth to planarize faceted, non-planar substrates. Controlled spalling is a promising high-throughput substrate reuse technology that could reduce substrate costs for III-V devices; however, the spalling fracture for (100)-oriented GaAs substrates produces a regularly corrugated surface of facets that are 5-20 um in height. We discuss how to planarize these surfaces using only a few minutes of HVPE growth and how to minimize the impact on throughput when integrating faceted wafers into a potential manufacturing process at scale.

epitaxy↗

Piston with insulating air gap formed by additive manufacturing

The present disclosure provides a piston, comprising: a skirt having an upper body portion; and a crown formed on the upper body portion by an additive manufacturing process, the crown including at least one air gap formed and positioned to reduce heat transfer from combustion to at least one cooling gallery formed in the piston.

Kelleher, Jordan E.↗