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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Cybersecurity and Privacy Aspects of Smart Contracts in the Energy Domain

Smart contracts (SCs) are a set of logical procedures that can run by individual peers participating within a Distributed Ledger Technology (DLT) network. By design, smart contracts inherit many of the benefits of DLT, including its immutability, scalability, and security properties. Nevertheless, they may introduce additional attack vectors, which can lead to cybersecurity explorations that could jeopardize the end-application ability to operate as intended or result in data leaks, and privacy violations. In this work, an exploration of known problems, and possible attack scenarios will be presented. This is followed by a set of proposed best practices and mitigation strategies that are intended to assist developers, researchers, and other relevant stakeholders to develop secure SC implementations.

Sebastian Cardenas, David J.↗
DOE OSTI2024

Commissioning Guidance for Energy Savings Performance Contracts (ESPCs)

This Commissioning Guidance for Energy Savings Performance Contracts (ESPCs) is DOE’s official guidance for ordering agencies under the current DOE ESPC IDIQ contract. This guidance document explains how commissioning of energy conservation measures (ECMs) and water conservation measures (WCMs) is incorporated into the ESPC process, roles and responsibilities in project commissioning, and key elements of commissioning. This document updates the previous version, released in 2015. This guidance can also be used as applicable in the development of ESPC ENABLE and UESC performance assurance plans.

Walker, Christine↗
DOE OSTI2025

Swing Contract-Based Valuation for Distributed Energy Resources in Transactive Energy Systems: A Reinforcement Learning Approach

With the proliferation of distributed energy resources (DERs) and power grids with high fractions of renewable energy, market constructs are evolving to allow DERs to participate in multiple possible markets, at different levels of grid hierarchy. The effective participation of DERs in market environments is aided by swing contract-based pricing mechanisms, whereby DERs have a two-part compensation structure – one for their reservation/commitment and another for performancedriven ex-post payment for their actual mobilization during dispatch. In this paper, we propose a reinforcement learningbased (Q-learning) approach that allows a rational DER agent to select the market it wants to participate in within a composite market environment where individual markets are coordinated by possibly different actors. The proposed Q-learning framework aids DERs in their self-valuation by implicitly maximizing their own payoff through market participation, assuming a swing contract-based compensation structure. We complement our work through simulation-based investigations where factors affecting the DER decision making process, such as parametric uncertainties in market (and grid) environments, are studied.

Naqvi, Syed Ahsan Raza↗
DOE OSTI2025

Utility Energy Service Contract Guide

This guide serves as a key resource for acquisition teams developing utility energy service contracts (UESC) with an emphasis on using a task order to acquire energy management services under a General Services Administration areawide contract. The guide features a compilation of templates to assist your efforts from acquisition planning through awarding a task order for design and installation.

Cali, Peter [National Renewable Energy Laboratory ↗
DOE OSTI2012

Empirical Performance Model-Driven Data Layout Optimization and Library Call Selection for Tensor Contraction Expressions

Empirical optimizers like ATLAS have been very effective in optimizing computational kernels in libraries. The best choice of parameters such as tile size and degree of loop unrolling is determined by executing different versions of the computation. In contrast, optimizing compilers use a model-driven approach to program transformation. While the model-driven approach of optimizing compilers is generally orders of magnitude faster than ATLAS-like library generators, its effectiveness can be limited by the accuracy of the performance models used. In this paper, we describe an approach where a class of computations is modeled in terms of constituent operations that are empirically measured, thereby allowing modeling of the overall execution time. The performance model with empirically determined cost components is used to perform data layout optimization together with the selection of library calls and layout transformations in the context of the Tensor Contraction Engine, a compiler for a high-level domain-specific language for expressing computational models in quantum chemistry. The effectiveness of the approach is demonstrated through experimental measurements on representative computations from quantum chemistry.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2011

Kirkendall Effect and Lattice Contraction in Nanocatalysts: A New Strategy to Enhance Sustainable Activity

Core-shell nanoparticles increasingly are found to be effective in enhancing catalytic performance through the favorable influence of the core materials on the active components at the surface. Yet, sustaining high activities under operating conditions often has proven challenging. Here we explain how differences in the components diffusivity affect the formation and stability of the core-shell and hollow nanostructures, which we ascribe to the Kirkendall effect. Using Ni nanoparticles as the templates, we fabricated compact and smooth Pt hollow nanocrystals that exhibit a sustained enhancement in Pt mass activity for oxygen reduction in acid fuel cells. This is achieved by the hollow-induced lattice contraction, high surface area per mass, and oxidation-resistant surface morphology - a new route for enhancing both the catalysts activity and durability. The results indicate challenges and opportunities brought by the nanoscale Kirkendall effect for designing, at the atomic level, nanostructures with a wide range of novel properties.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2013

Contractions of AdS brane algebra and superGalileon Lagrangians

We examine AdS Galileon Lagrangians using the method of nonlinear realization. By contractions (1) flat curvature limit, (2) non-relativistic brane algebra limit, and (3) (1) + (2) limits we obtain DBI, Newton-Hoock, and Galilean Galileons, respectively. We make clear how these Lagrangians appear as invariant 4-forms and/or pseudo-invariant Wess-Zumino (WZ) terms using Maurer-Cartan (MC) equations on the coset G/SO(3, 1). We show the equations of motion are written in terms of the MC forms only and explain why the inverse Higgs condition is obtained as the equation of motion for all cases. The supersymmetric extension is also examined using a supercoset SU(2, 2 Double-Vertical-Line 1)/(SO(3, 1) Multiplication-Sign U(1)) and five WZ forms are constructed. They are reduced to the corresponding five Galileon WZ forms in the bosonic limit and are candidates for supersymmetric Galileon action.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Simulation of dilute polymeric fluids in a three-dimensional contraction using a multiscale FENE model

The multiscale FENE model is applied to a 3D square-square contraction flow problem. For this purpose, the stochastic Brownian configuration field method (BCF) has been coupled with our fully parallelized three-dimensional Navier-Stokes solver NaSt3DGPF. The robustness of the BCF method enables the numerical simulation of high Deborah number flows for which most macroscopic methods suffer from stability issues. The results of our simulations are compared with that of experimental measurements from literature and show a very good agreement. In particular, flow phenomena such as a strong vortex enhancement, streamline divergence and a flow inversion for highly elastic flows are reproduced. Due to their computational complexity, our simulations require massively parallel computations. Using a domain decomposition approach with MPI, the implementation achieves excellent scale-up results for up to 128 processors.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2013

OHMIC HEATING SUSPENDS, NOT REVERSES, THE COOLING CONTRACTION OF HOT JUPITERS

We study the radius evolution of close-in extra-solar Jupiters under Ohmic heating, a mechanism that was recently proposed to explain the large observed sizes of many of these planets. Planets are born with high entropy and they subsequently cool and contract. We focus on two cases: first, that Ohmic heating commences when the planet is hot (high entropy); and second, that it commences after the planet has cooled. In the former case, we use analytical scaling and numerical experiments to confirm that Ohmic heating is capable of suspending the cooling as long as a few percent of the stellar irradiation is converted into Ohmic heating and the planet has a surface wind that extends to pressures of {approx}10 bar or deeper. For these parameters, the radii at which cooling is stalled are consistent with (or larger than) the observed radii of most planets. The only two exceptions are WASP-17b and HAT-P-32b. In contrast to the high entropy case, we show that Ohmic heating cannot significantly re-inflate planets after they have already cooled. This leads us to suggest that the diversity of radii observed in hot Jupiters may be partially explained by the different epochs at which they are migrated to their current locations.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2013

Galileon bounce after ekpyrotic contraction

We consider a simple cosmological model that includes a long ekpyrotic contraction stage and smooth bounce after it. Ekpyrotic behavior is due to a scalar field with a negative exponential potential, whereas the Galileon field produces bounce. We give an analytical picture of how the bounce occurs within the weak gravity regime, and then perform numerical analysis to extend our results to a non-perturbative regime.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2012

THE CHANGE IN JUPITER'S MOMENT OF INERTIA DUE TO CORE EROSION AND PLANETARY CONTRACTION

We explore the change in Jupiter's normalized axial moment of inertia (NMOI) assuming that Jupiter undergoes core erosion. It is found that Jupiter's contraction combined with an erosion of 20 M{sub Circled-Plus} from a primordial core of 30 M{sub Circled-Plus} can significantly change Jupiter's NMOI over time. It is shown that Jupiter's NMOI could have changed from {approx}0.235 to {approx}0.264 throughout its evolution. We find that an NMOI value of {approx}0.235 as suggested by dynamical models could, in principle, be consistent with Jupiter's primordial internal structure. Low NMOI values, however, persist only for the first {approx}10{sup 6} years of Jupiter's evolution. Re-evaluation of dynamical stability models as well as more sophisticated evolution models of Jupiter with core erosion seem to be required in order to provide more robust estimates for Jupiter's primordial NMOI.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

PV System 'Availability' as a Reliability Metric -- Improving Standards, Contract Language and Performance Models

The use of the term 'availability' to describe a photovoltaic (PV) system and power plant has been fraught with confusion for many years. A term that is meant to describe equipment operational status is often omitted, misapplied or inaccurately combined with PV performance metrics due to attempts to measure performance and reliability through the lens of traditional power plant language. This paper discusses three areas where current research in standards, contract language and performance modeling is improving the way availability is used with regards to photovoltaic systems and power plants.

14 SOLAR ENERGY↗
DOE OSTI2016

Federal Energy Savings Performance Contracts: Frequently Asked Questions on the Scope of 42 U.S.C. § 8287 et seq.

Document provides clarification and guidance on issues commonly raised regarding the scope of 42 U.S.C. § 8287 et seq. It is a supplement to the Federal Energy Management Program's extensive collection of materials that are available to assist federal agencies execute successful energy savings performance contract (ESPC) projects.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Performance Assurance Planning: Continuous Design-Level Performance of Each Energy Conservation Measure in a Utility Energy Service Contract is Fundamental to Achieving Projected Results

An energy savings performance contract energy sales agreement (ESPC ESA) is a project structure, similar to a power purchase agreement, that uses the multiyear ESPC authority to implement renewable energy projects (referred to as ESA energy conservation measures [ECMs]) on federal buildings or land. The ESA ECM is initially privately owned for tax-incentive purposes, and the federal agency purchases the electricity it produces. An ESPC ESA is one of the most cost-effective methods for implementing on-site distributed energy projects at civilian federal agency sites.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Energy Savings Performance Contracting for Small Projects

Energy Savings Performance Contracting (ESPC) is a budget-neutral approach to make building improvements that reduce energy and water use and increase operational efficiency. ESPC can help public-sector planners use tomorrow’s energy savings to fund today's facility and infrastructure upgrades. This resource highlights strategies and case studies for implementing ESPC in smaller towns, rural counties, and small school districts to complete energy upgrades and maximize energy and cost savings.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2020

Flexible Service Contracting for Risk Management within Integrated Transmission and Distribution Systems

The general objective of our project has been to investigate the ability of Independent Distribution System Operators (IDSOs), functioning as linkage agents for Integrated Transmission and Distribution (ITD) systems, to facilitate the flexible availability and usage of reserve in support of ITD system operations. This general objective is in accordance with Order 2222 of the U.S. Federal Energy Regulatory Commission (FERC), titled “Participation of Distributed Energy Resource Aggregations in Markets Operated by Regional Transmission Organizations and Independent System Operators”. The Final Rule for FERC Order 2222 was issued on September 17, 2020. The primary contribution of our project is that we have formulated an innovative energy management Transactive Energy Design (TES) approach for ITD systems that provides promising support for our project objective. Specifically, we have developed a new type of IDSO-managed TES design for distribution system operations, as well as new types of swing contracts permitting IDSOs to participate in transmission system operations as providers of reserve harnessed from distribution system resources in return for appropriate compensation. Together, these design elements constitute a scalable market-based approach facilitating efficient reserve procurement for ITD system operations from a fuller range of power resources. The efficacy of our approach has been demonstrated by means of detailed conceptual analyses as well as test case simulations. To implement the latter, we have developed the ITD TES Platform V2.0, a computational platform that permits the modeling and software implementation of ITD system operations over time. The Electric Reliability Council of Texas (ERCOT) energy region has been used as the empirical anchor for the development of this platform. Our conceptual and test-case work has been reported in a Wiley/IEEE Press book, two refereed book chapters, and seven refereed journal articles. The key components comprising the ITD TES Platform V2.0 have been released as documented open-source software at online GitHub repositories.

24 POWER TRANSMISSION AND DISTRIBUTION↗