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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Clean Energy Technologies for Economic and Environmental Transitions

Energy systems across the world are undergoing fundamental transformations. Electricity and heat production are becoming cleaner and more distributed, driven by declining energy prices and higher technology efficiencies, as well as a desire to reduce environmental impact. The technologies that produce clean energy, such as solar photovoltaic panels, wind turbines, and lithium ion batteries for vehicles and storage, depend less on fuel costs and more on technology costs and global manufacturing and trade. Therefore, innovations in technology manufacturing, systems integration, and deployment can reduce costs of materials, equipment, labor, operations, and transportation, across all the links in the energy supply chain. The clean energy trends are expected to continue and perhaps grow through expansion of clean energy technologies for industrial and transportation sectors, although there are many possible future scenarios due to the diversity of resources and societal objectives in different communities, countries, and regions. This presentation will summarize the status and potential futures of key clean energy technologies and their manufacturing, deployment, and integration with other energy systems and sectors.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2022

JISEA Annual Meeting: Clean Energy for Oil and Gas Topic Table

Presentation on clean energy for oil and gas topic discussion table at the 2022 JISEA annual meeting. Many refineries may have wind and solar resources and clean energy technology costs are declining. JISEA created an oil and gas consortium including Baker Hughes, Conoco Phillips, Extraction Oil & Gas, INGAA Foundation, and Kinder Morgan to explore potential pathways for integrating clean energy into oil and gas operations. This presentation goes over JISEA case studies that demonstrate reliable and affordable clean power for oil and gas operations. JISEA used the REopt Energy Planning Platform and evaluated several potential future scenarios.

clean energy↗
DOE OSTI2024

Trends in Cybersecurity Threats to Clean Energy

As deployments of clean energy generation and storage assets continue to grow, the increased attack surface creates a greater risk for cyber threats, but is clean energy truly a target for cyber adversaries? This poster will present research on the trends in cyber incidents that have affected clean energy companies and assets as well as the trends in disclosed and exploited vulnerabilities. From a series of ransomware attacks on European wind manufacturers, to vulnerabilities exploited in solar assets to turn controllers into botnets, to attacks on communication infrastructure that have resulted in extended outages of remote control and monitoring, we explore the techniques used and the impacts to the clean energy sector. Key takeaways include understanding of how OT-focused malware is becoming more flexible and more destructive, how known vulnerabilities are being exploited, the growing number of IT and OT attacks that use built in tools and functionalities. Additionally, we highlight the presumed motivations and targeted sectors for various identified cyber adversaries. Viewers will leave with an understanding of how recent headlines fit into the development of cyberattack trends and what preventions they may need to take to protect against increasingly popular tactics.

14 SOLAR ENERGY↗
DOE OSTI2014

Clean Cities Now, Vol. 18, No. 1

The Spring 2014 edition of the semi-annual newsletter for the U.S. Department of Energy's Clean Cities initiative. The newsletter includes feature stories on deployment of alternative fuels and advanced vehicles, and articles on Clean Cities coalition successes across the country.

advanced vehicles↗
DOE OSTI2022

Mechanisms of Interface Cleaning in Heterostructures Made from Polymer‐Contaminated Graphene

Abstract Heterostructures obtained from layered assembly of 2D materials such as graphene and hexagonal boron nitride have potential in the development of new electronic devices. Whereas various materials techniques can now produce macroscopic scale graphene, the construction of similar size heterostructures with atomically clean interfaces is still unrealized. A primary barrier has been the inability to remove polymeric residues from the interfaces that arise between layers when fabricating heterostructures. Here, the interface cleaning problem of polymer‐contaminated heterostructures is experimentally studied from an energy viewpoint. With this approach, it is established that the interface cleaning mechanism involves a combination of thermally activated polymer residue mobilization and their mechanical actuation. This framework allows a systematic approach for fabricating record large‐area clean heterostructures from polymer‐contaminated graphene. These heterostructures provide state‐of‐the‐art electronic performance. This study opens new strategies for the scalable production of layered materials heterostructures.

Huang, Zhujun↗
DOE OSTI2024

Comparison of effectiveness and energy use of airborne pathogen mitigation measures to meet clean air targets in a prototypical office building

Organizations such as ASHRAE and the Centers for Disease Control and Prevention (CDC) have proposed guidelines for controlling infectious aerosols in buildings, which can be met through measures such as modified operation of the heating, ventilation, and air-conditioning (HVAC) system or incorporating air-cleaning technologies. However, more research is needed to understand the trade-offs between health, energy, and comfort aspects when designing measures for these guidelines. To address this gap, this paper presents an analysis using new models for air-cleaning technologies, including in-duct and in-room germicidal ultraviolet (GUV) systems and portable air cleaners (PACs). These models are incorporated into an existing prototypical office building model and six measures are designed to meet ASHRAE Standard 241 and CDC clean air targets: MERV 13 HVAC filtration, maximum outdoor air supplied to the building, PACs, and in-duct, upper-room, and whole-room GUV. The measures are simulated for an office building in a cool and humid climate compared against a baseline simulation using MERV 8 filtration. The results show that all measures, except for the maximum outdoor air case, can meet the ASHRAE 241 standard without significant impacts on energy or comfort. The HVAC system measures were not able to meet the CDC target with the default system sizing and lead to significant energy increases, while the in-room measures were able to meet the CDC target with small impacts on energy consumption. Finally, this paper consolidates the simulation findings and provides practical guidance for building operators to meet clean air targets while limiting energy and comfort impacts.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2024

Aerosol‐Correlated Cloud Activation for Clean Conditions in the Tropical Atlantic Boundary Layer During LASIC

Abstract Aerosol measurements during the DOE ARM Layered Atlantic Smoke Interactions with Clouds (LASIC) campaign were used to quantify the differences between clean and smoky cloud condensation nuclei (CCN) budgets. Accumulation‐mode particles accounted for ∼70% of CCN at supersaturations <0.3% in clean and smoky conditions. Aitken‐mode particles contributed <20% and sea‐spray‐mode particles <10% at supersaturations <0.3%, but at supersaturations >0.3% Aitken particles contributions increased to 30%–40% of clean CCN. For clean conditions, the Hoppel minimum diameter was correlated to the accumulation‐mode number concentration, indicating aerosol‐correlated cloud activation was controlling the lower diameter cutoff for which particles serve as CCN. For smoky conditions, the contributions of Aitken particles increase and the correlation of cloud activation to accumulation‐mode particles is masked by the lower‐hygroscopicity smoke. These results provide the first multi‐month in situ quantitative constraints on the role of aerosol number size distributions in controlling cloud activation in the tropical Atlantic boundary layer.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Theory of optical responses in clean multi-band superconductors

Electromagnetic responses in superconductors provide valuable information on the pairing symmetry as well as physical quantities such as the superfluid density. However, at the superconducting gap energy scale, optical excitations of the Bogoliugov quasiparticles are forbidden in conventional Bardeen-Cooper-Schrieffer superconductors when momentum is conserved. Accordingly, far-infrared optical responses have been understood in the framework of a dirty-limit theory by Mattis and Bardeen for over 60 years. Here we show, by investigating the selection rules imposed by particle-hole symmetry and unitary symmetries, that intrinsic momentum-conserving optical excitations can occur in clean multi-band superconductors when one of the following three conditions is satisfied: (i) inversion symmetry breaking, (ii) symmetry protection of the Bogoliubov Fermi surfaces, or (iii) simply finite spin-orbit coupling with unbroken time reversal and inversion symmetries. This result indicates that clean-limit optical responses are common beyond the straightforward case of broken inversion symmetry. We apply our theory to optical responses in FeSe, a clean multi-band superconductor with inversion symmetry and significant spin-orbit coupling. This result paves the way for studying clean-limit superconductors through optical measurements.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Toward clean suspended CVD graphene

The application of suspended graphene as electron transparent supporting media in electron microscopy, vacuum electronics, and micromechanical devices requires the least destructive and maximally clean transfer from their original growth substrate to the target of interest. Here, we use thermally evaporated anthracene films as the sacrificial layer for graphene transfer onto an arbitrary substrate. We show that clean suspended graphene can be achieved via desorbing the anthracene layer at temperatures in the 100 °C to 150 °C range, followed by two sequential annealing steps for the final cleaning, using a Pt catalyst and activated carbon. The cleanliness of the suspended graphene membranes was analyzed employing the high surface sensitivity of low energy scanning electron microscopy and X-ray photoelectron spectroscopy. A quantitative comparison with two other commonly used transfer methods revealed the superiority of the anthracene approach to obtain a larger area of clean, suspended CVD graphene. Lastly, our graphene transfer method based on anthracene paves the way for integrating cleaner graphene in various types of complex devices, including the ones that are heat and humidity sensitive.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Plasma ignition and detection for in-situ cleaning of 1.3 GHz 9-cell cavities

Superconducting Radio Frequency (SRF) cavities performance preservation is crucial, from vertical test to accelerator operation. Field Emission (FE) is still one of the performance limiting factors to overcome and plasma cleaning has been proven successful by the Spallation Neutron Source (SNS), in cleaning field emitters and increasing the work function of Nb. A collaboration has been established between Fermi National Accelerator Laboratory (FNAL), SLAC National Accelerator Laboratory and Oak Ridge National Laboratory (ORNL) with the purpose of applying plasma processing to the Linac Coherent Light Source-II (LCLS-II) cavities, in order to minimize and overcome field emission without affecting the high Q of nitrogen-doped cavities. The cleaning for LCLS-II will follow the same plasma composition adopted at SNS, which allows in-situ processing of cavities installed in cryomodules from hydrocarbon contaminants. A novel method for plasma ignition has been developed at FNAL: a plasma glow discharge is ignited using high order modes to overcome limitations imposed by the fundamental power coupler, allowing in-situ cleaning for cavities in cryomodule. The plasma can be easily ignited and tuned in each of the cavity cells using low RF power. A method for plasma detection has been developed as well, which allows the detection of the plasma location in the cavity without the need of cameras at both cavity ends. The presented method can be applied to other multi-cell cavity designs, even for accelerators where the coupling for the fundamental modes at room temperature is very weak.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Improving the performance of high-laser-damage-threshold, multilayer dielectric pulse-compression gratings through low-temperature chemical cleaning

A low-temperature chemical cleaning approach has been developed to improve the performance of multilayer dielectric pulse-compressor gratings for use in the OMEGA EP laser system. X-ray photoelectron spectroscopy results guided the selection of targeted cleaning steps to strip specific families of manufacturing residues without damaging the grating's fragile 3D profile. Grating coupons that were cleaned using the optimized method consistently met OMEGA EP requirements on diffraction efficiency and 1054 nm laser-damage resistance at 10 ps. The disappearance of laser-conditioning effects for the highest-damage-threshold samples suggests a transition from a contamination-driven laser-damage mechanism to defect-driven damage for well-cleaned components.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2023

First Experience with Liquid Nitrogen Cleaning

Field emission caused by microscopic particulate contamination is a limiting factor for the performance of superconducting RF (SRF) cavities. In an SRF based accelerator, particulates may be transported over the surface of an operational SRF cavity, becoming field emitters and consequentially degrading the performance of the SRF cavity. The most commonly used method for removing particulates from cavity surfaces is high-pressure ultra-pure water rinsing. We are developing a novel high-pressure liquid nitrogen cleaning technique that may possibly enable superior cleaning power and particulate removal from cavities in a cryomodule without taking apart the cryomodule components. This technique provides cleaning mechanisms beyond what are accessible by its high-pressure water rinsing counterpart and leaves no residues on the cleaned surface.

Ruber, R.J.M.Y.↗
DOE OSTI2012

Clean Technology Evaluation & Workforce Development Program

The overall objective of the Clean Technology Evaluation portion of the award was to design a process to speed up the identification of new clean energy technologies and match organizations to testing and early adoption partners. The project was successful in identifying new technologies targeted to utilities and utility technology integrators, in developing a process to review and rank the new technologies, and in facilitating new partnerships for technology testing and adoption. The purpose of the Workforce Development portion of the award was to create an education outreach program for middle & high-school students focused on clean technology science and engineering. While originally targeting San Diego, California and Cambridge, Massachusetts, the scope of the program was expanded to include a major clean technology speaking series and expo as part of the USA Science & Engineering Festival on the National Mall in Washington, D.C.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2013

Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt% or 2 wt%) were used at 55°C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Exploring Engineering Control through Process Manipulation of Radioactive Liquid Waste Tank Chemical Cleaning

One method of remediating legacy liquid radioactive waste produced during the cold war, is aggressive in-tank chemical cleaning. Chemical cleaning has successfully reduced the curie content of residual waste heels in large underground storage tanks; however this process generates significant chemical hazards. Mercury is often the bounding hazard due to its extensive use in the separations process that produced the waste. This paper explores how variations in controllable process factors, tank level and temperature, may be manipulated to reduce the hazard potential related to mercury vapor generation. When compared using a multivariate regression analysis, findings indicated that there was a significant relationship between both tank level (p value of 1.65x10 -23 ) and temperature (p value of 6.39x10 -6 ) to the mercury vapor concentration in the tank ventilation system. Tank temperature showed the most promise as a controllable parameter for future tank cleaning endeavors. Despite statistically significant relationships, there may not be confidence in the ability to control accident scenarios to below mercury’s IDLH or PAC-III levels for future cleaning initiatives.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Test Results and Comparison of Triaxial Strength Testing of Waste Isolation Pilot Plant Clean Salt

This memorandum documents laboratory thermomechanical triaxial strength testing of Waste Isolation Pilot Plant (WIPP) clean salt. The limited study completed independent, adjunct laboratory tests in the United States to assist in validating similar testing results being provided by the German facilities. The testing protocol consisted of completing confined triaxial, constant strain rate strength tests of intact WIPP clean salt at temperatures of 25°C and 100°C and at multiple confining pressures. The stratigraphy at WIPP also includes salt that has been labeled “argillaceous.” The much larger test matrix conducted in Germany included both the so-called clean and argillaceous salts. When combined, the total database of laboratory results will be used to develop input parameters for models, assess adequacy of existing models, and predict material behavior. These laboratory studies are also consistent with the goals of the international salt repository research program. The goal of this study was to complete a subset of a test matrix on clean salt from the WIPP undertaken by German research groups. The work was performed at RESPEC in Rapid City, South Dakota. A rigorous Quality Assurance protocol was applied, such that corroboration provides the potential of qualifying all of the test data gathered by German research groups.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Southwest Regional Clean Energy Incubation Initiative (SRCEII)

The Austin Technology Incubator’s (ATI’s) Clean Energy Incubator at the University of Texas at Austin (ATI-CEI) utilized the National Incubator Initiative for Clean Energy (NIICE) funding to establish the Southwest Regional Clean Energy Incubation Initiative, composed of clean energy incubators from The University of Texas at Austin (UT-Austin), The University of Texas at El Paso (UTEP), The University of Texas at San Antonio (UTSA), and Texas A&M University (TAMU).

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2018

Commercial Property Assessed Clean Energy (CPACE) for Tax-Exempt and Public Entities (“CivicPACE”)

This report summarizes the work of the CivicPACE team to open the market for property assessed clean energy financing for the nonprofit, tax exempt sector. Property Assessed Clean Energy (PACE) finances property improvements that are paid back through a line item on the property owner’s tax bill. Most states restrict such improvements to renewable energy and energy efficiency, although they may include water conservation and disaster related improvements such as hurricane or earthquake preparedness. When such projects are developed for commercial properties, it is referred to as commercial PACE or CPACE. When CPACE applies to tax exempt or nonprofit organizations, we refer to it as CivicPACE. CivicPACE also represents the name of this program. The purpose of the CivicPACE project was to help nonprofit tax-exempt organizations such as affordable housing, faith-based institutions, and schools gain greater access to financing for solar energy deployment through PACE. As such, the lessons learned and best practices from the CivicPACE team work is intended for state and municipal program designers, PACE administrators, solar installers, and nonprofit organizations. CPACE is experiencing rapid growth. Cumulative CPACE financing grew from 8.2 million in 2010 to 111 million in 2014 to 588 million in 2017. Renewable energy, mostly solar, represents about a quarter of the financing; the nonprofit sector represents about 10% of total financing. The Project Team was formed in early 2015 when solar financing options were limited for nonprofits (NPOs). Traditional bank financing was difficult for nonprofit organizations to secure since they are often viewed as a credit risk. Despite the growth of CPACE, few tax-exempt organizations were using the financing mechanism at the start of 2015. Nonetheless, CPACE financing appeared to have tremendous potential for solar development for tax-exempt organizations such as schools, churches, and multifamily affordable housing, because it addresses many of the traditional nonprofit financing roadblocks, such as credit risk. Given the benefits and the rapid growth of CPACE, the opportunity to expand CPACE financing for solar development on tax-exempt buildings was timely. The Project team was comprised of The Solar Foundation (TSF), Urban Ingenuity (UI), and Clean Energy Solutions, Inc. (CESI). The Solar Foundation was the Principal Investigator and overall team lead. The Solar Foundation is an independent 501(c)(3) nonprofit organization whose mission is to accelerate adoption of the world’s most abundant energy source. PACE financing specialist Urban Ingenuity was the lead for the team for the pilot projects. Clean Energy Solutions (CESI) was the lead on the market analysis, financial modeling, and HUD regulatory issues for PACE financed solar development on affordable housing. The CivicPACE team focused on four key activities to help open the market for CPACE financing of solar development for nonprofit entities: research, pilot projects, technical assistance, and information dissemination.

14 SOLAR ENERGY↗