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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

Feature-Based PMU Event Classification under Variable PMU Participation and Overlapping Events

Danovo Energy Solution's presented its paper named: Feature-Based PMU Event Classification under Variable PMU Participation and Overlapping Events at the 2026 Georgia Tech Fault & Disturbance Analysis Conference. The full paper can be found at OSTI ID# 3169150 Paper Abstract—Phasor Measurement Units (PMUs) stream time synchronized, high-resolution measurements from the grid, enabling data-driven techniques for event detection and classification. Accurate event classification improves grid reliability and stability. Events can be detected by varying numbers of PMUs and exhibit different durations depending on the event type. This variability challenges standard classifiers that require uniform input sizes. Moreover, multiple events may coincide, which increases classification complexity. Standard classifiers assign each instance to the class with the highest predicted probability, whereas overlapping events may exhibit comparable probabilities across multiple classes. In this study, to handle data size variability, we extract a wide range of time–frequency domain features from all available PMUs for each event into a fixed-length vector, facilitating the application of standard machine learning classifiers, including Random Forest, XGBoost, LightGBM, Support Vector Machine, and Multilayer Perceptron. To account for overlapping events, a probabilistic post-processing step is applied. For a given data instance, if multiple predicted class probabilities exceed 30% and the differences between them are less than 10%, the event is assigned to multiple classes. Experiments using real-world PMU data demonstrate that the Random Forest and XGBoost models achieve the highest accuracy, while the proposed post-processing method yields perfect classification performance on external unseen test sets.

Nematirad, Reza [Danova Energy Solutions]↗

Spectrum and Stabilization in Hyperbolic Problems

We study the connection between the stabilization of solutions of a mixed hyperbolic problem and spectral properties of the corresponding elliptic boundary value problem. We consider the first mixed problem for the wave equation in bounded and unbounded domains in ℝ{sup n}, determine the class of its energy solutions, and represent the solutions in terms of the Bochner–Stieltjes integral. We study how the spectrum of the elliptic operator affects the behavior of local energy of a solution and describe a method which allows us to study the stabilization of solutions with the help of estimates in the spectral parameter for solutions of the stationary problem on the upper half-plane.

97 MATHEMATICS AND COMPUTING↗

Mechanical energy flow models of rods and beams

It has been proposed that the flow of mechanical energy through a structural/acoustic system may be modeled in a manner similar to that of flow of thermal energy/in a heat conduction problem. If this hypothesis is true, it would result in relatively efficient numerical models of structure-borne energy in large built-up structures. Fewer parameters are required to approximate the energy solution than are required to model the characteristic wave behavior of structural vibration by using traditional displacement formulations. The energy flow hypothesis is tested in this investigation for both longitudinal vibration in rods and transverse flexural vibrations of beams. The rod is shown to behave approximately according to the thermal energy flow analogy. However, the beam solutions behave significantly differently than predicted by the thermal analogy unless locally-space-averaged energy and power are considered. Several techniques for coupling dissimilar rods and beams are also discussed. Illustrations of the solution accuracy of the methods are included.

Wohlever, J. C.↗

Approximate Boltzmann distributions in quantum approximate optimization

Approaches to compute or estimate the output probability distributions from the quantum approximate optimization algorithm (QAOA) are needed to assess the likelihood it will obtain a quantum computational advantage. We analyze output from QAOA circuits solving 7200 random MaxCut instances, with $n$ = 14–23 qubits and depth parameter $p$ ≤ 12 and find that the average basis state probabilities follow approximate Boltzmann distributions: The average probabilities scale exponentially with their energy (cut value), with a peak at the optimal solution. Furthermore, we describe the rate of exponential scaling or effective temperature in terms of a series with a leading-order term $T$ ~ $C$ min /$n$ $\sqrt{p}$, with $C$ min the optimal solution energy. Using this scaling, we generate approximate output distributions with up to 38 qubits and find these give accurate accounts of important performance metrics in cases we can simulate exactly.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Supporting Clean Energy Development in Swaziland

Swaziland, a country largely dependent on regional fossil fuel imports to meet power needs, is vulnerable to supply changes and price shocks. To address this challenge, the country's National Energy Policy and Implementation Strategy prioritizes actions to enhance energy independence through scaling up renewable energy and energy efficiency. With approximately 70 percent of the country lacking electricity, Swaziland is also strongly committed to expanding energy access to support key economic and social development goals. Within this context, energy security and energy access are two foundational objectives for clean energy development in Swaziland. The partnership between the Swaziland Energy Regulatory Authority and the Clean Energy Solutions Center led to concrete outcomes to support clean energy development in Swaziland. Improving renewable energy project licensing processes will enable Swaziland to achieve key national objectives to expand clean energy access and transition to greater energy independence.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Kansas State University Center for Sustainable Energy

This project sought to develop next generation bioenergy/biorefining systems to reduce greenhouse gas impacts, stabilize rural economies, and establish US leadership in 21st century energy solutions. In the past several years the U.S. Department of Energy (DOE), USDA, and other partners have developed the “25 x 25” vision, with a goal of replacing 25% of our petroleum needs with renewables by 2025. To achieve this ambitious goal, more efficient conversion of biomass to fuels and chemicals must be realized. In most existing facilities based on fermenting the starches of the biomass feedstock to alcohols, only about 33% of the feedstock mass is converted to a fuel product. Here, research was conducted that advanced our ability to convert the majority of the biomass feedstock to fuels and chemicals using thermochemical processing. Additionally, educational training tools were developed and employed for training the next generation of scientists and engineers who will implement this technology.

09 BIOMASS FUELS↗

Increasing Resiliency Through Renewable Energy Microgrids

This paper describes a methodology to quantify the economic and resiliency benefit provided by renewable energy (RE) in a hybrid RE-storage-diesel microgrid. We present a case study to show how this methodology is applied to a multi-use/ multi-function telecommunications facility in southern California. In the case study, we first identify photovoltaic (PV) and battery energy storage system (BESS) technologies that minimize the lifecycle cost of energy at the site under normal, grid-connected operation. We then evaluate how those technologies could be incorporated alongside existing diesel generators in a microgrid to increase resiliency at the site, where resiliency is quantified in terms of the amount of time that the microgrid can sustain the critical load during a grid outage. We find that adding PV and BESS to the existing backup diesel generators with a fixed fuel supply extends the amount of time the site could survive an outage by 1.8 days, from 1.7 days for the existing diesel-only backup system to 3.5 days for the PV/diesel/BESS hybrid system. Furthermore, even after diesel fuel supplies are exhausted, the site can continue to operate critical loads during daytime hours using just the PV/BESS when there is sufficient solar resource. We find that the site can save approximately 100,000 dollars in energy costs over the 25-year lifecycle while doubling the amount of time they can survive an outage. Here, the methodology presented here provides a template for increasing resiliency at telecomm sites by implementing renewable energy solutions, which provide additional benefits of carbon emission reduction and energy cost savings.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Strengthening U.S. National Security Through Advanced Energy Innovation

NREL's work in strategic energy security is focused on keeping the United States secure and its citizens safe by applying expertise in advanced energy systems and technologies to prevent energy system disruptions from any source, natural or human. NREL pursues national security objectives by providing partners an accurate understanding of national and international security implications of global energy trends; novel installation, facility, and operational energy solutions; access to NREL R&D capabilities to incorporate advanced energy technologies and biomaterials into mission requirements; and the ability to test future technologies using large-scale grid modeling.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Development of Approaches to Model Excited State Charge and Energy Transfer in Solution

The development of next generation energy conversion and catalytic systems requires fundamental understanding of the interplay between photo-excitation and the resulting proton and electron transfer processes that occur in solution. To address these challenges requires accurate and efficient methods to compute ground and excited states, as well as the ability to treat the dynamics of energy transfer in the presence of solvent fluctuations. Our team is developing accurate and efficient theoretical models for solution phase reactions. These developments provide an improved understanding of photo-initiated excitations, electron transfer, and proton coupled electron transfer processes. Our research team brings together expertise in electron and nuclear dynamics (classical and quantum), electronic structure, and analysis of solvation networks. We are developing and validating techniques for modeling condensed phase charge and energy transfer and to simulate the methods to monitor them using optical and vibrational spectroscopy.

74 ATOMIC AND MOLECULAR PHYSICS↗

Catalyzing Gender Equality-Focused Clean Energy Development in West Africa

The Economic Community of West African States (ECOWAS) Regional Center for Renewable Energy and Energy Efficiency (ECREEE) partnered with the Clean Energy Solutions Center (Solutions Center), the African Development Bank and other institutions to develop a Situation Analysis of Energy and Gender Issues in ECOWAS Member States. Through a systematic approach to assess interlinked gender and energy issues in the region, the report puts forth a number of key findings. This brochure highlights ECREEE's partnership with the Solutions Center and key findings from the report.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Scaling whole-chip QAOA for higher-order ising spin glass models on heavy-hex graphs

Abstract We show that the quantum approximate optimization algorithm (QAOA) for higher-order, random coefficient, heavy-hex compatible spin glass Ising models has strong parameter concentration across problem sizes from 16 up to 127 qubits for p = 1 up to p = 5, which allows for computationally efficient parameter transfer of QAOA angles. Matrix product state (MPS) simulation is used to compute noise-free QAOA performance. Hardware-compatible short-depth QAOA circuits are executed on ensembles of 100 higher-order Ising models on noisy IBM quantum superconducting processors with 16, 27, and 127 qubits using QAOA angles learned from a single 16-qubit instance using the JuliQAOA tool. We show that the best quantum processors find lower energy solutions up to p = 2 or p = 3, and find mean energies that are about a factor of two off from the noise-free distribution. We show that p = 1 QAOA energy landscapes remain very similar as the problem size increases using NISQ hardware gridsearches with up to a 414 qubit processor.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Enhanced Geothermal Shot Analysis for the Geothermal Technologies Office

In 2021, the U.S. Department of Energy (DOE) began the Energy Earthshots initiatives to accelerate breakthroughs of reliable clean energy solutions within the next 10 years. In 2022, the National Renewable Energy Laboratory (NREL) was asked by the DOE Geothermal Technologies Office (GTO) to provide analysis for developing Energy Earthshot targets for Enhanced Geothermal Systems (EGS), human-made underground reservoirs that extract thermal energy from the earth for electricity generation and/or heating applications. The Enhanced Geothermal Shot analysis is based on the technology assumptions in the 2019 GTO report GeoVision: Harnessing the Heat Beneath Our Feet. For Earthshot, we updated some of the technology cost and performance assumptions based on recent technology advances and updated the EGS resource potential to include more detailed analysis. We used the updated EGS supply cost curves to forecast the amount of geothermal electricity generation that could be deployed in the US by 2050 using a capacity expansion model. The results were used to develop a cost target for EGS. On September 8th, 2022, the Enhanced Geothermal Shot was announced. Its target - reduce the cost of EGS by 90%, to $45 per megawatt hour by 2035. This paper summarizes the cost and resource assumptions used in the Enhanced Geothermal Shot. It describes the assumptions used in the Regional Energy Deployment System (ReEDS) capacity expansion model to forecast geothermal deployment and discusses the results.

15 GEOTHERMAL ENERGY↗

In-Conduit Hydropower for Public Water Supply Systems: Development Challenges and Costs

Conduit hydropower leverages existing water infrastructure to provide energy solutions, though deployment has been slow. A 2022 US Department of Energy (DOE)–funded report led by Oak Ridge National Laboratory (ORNL) summarizes a reconnaissance-level study of hydropower potential at national conduits (Kao et al., 2022). The report includes power and energy estimates across three major sectors of conduit hydropower potential: municipal, agricultural, and industrial. Water resources include public water supply systems (municipal and industrial), irrigation canal systems (agricultural), thermoelectric cooling systems (industrial), and wastewater systems (municipal and industrial). In total, 1.41 GW of power potential was estimated nationwide. Subsequently, DOE has funded ORNL through the Conduit Hydropower Engineering, Evaluation, and Technology Acceleration project (CHEETA) to improve deployment potential for conduit hydropower. Work thus far has focused on “in-conduit” hydropower (ICH)—or “in-pipe” hydropower—for public water supply systems, though the project is planning to cover conduit hydropower more broadly. The timeline of ORNL’s conduit hydropower related research and development (R&D) is shown in Figure 1. The results of CHEETA should benefit the hydropower industry by providing insights into costs, barriers, and other considerations that impact project development. The hydropower industry and municipal/industrial conduit stakeholders will use the output to inform development decisions and advance low-impact hydropower growth in the US.

13 HYDRO ENERGY↗

Micro-Hydropower and Aquatic Restoration on Lands of the Eastern Band of Cherokee Indians

Rural and Tribal communities in Southern Appalachia face persistent challenges in energy access owing to rugged terrain, dense forest cover, and limited infrastructure. The Eastern Band of Cherokee Indians (EBCI) is a federally recognized Tribe whose ancestral homelands include much of Southern Appalachia. The Tribe’s present-day homeland, termed the Qualla Boundary, lies in the heart of the region, where the extreme ruggedness of the Blue Ridge Mountains exacerbates challenges to energy access. For the EBCI, these challenges also intersect with a deep cultural commitment to stewardship of land and water. The Tribe has explored multiple energy solutions, with hydropower serving as an existing and realized source of energy for the region’s communities. However, the EBCI’s commitment to protecting aquatic systems has led not only to a historical lack of endorsement of new conventional hydropower on Tribal lands but also to ongoing efforts to remove the area’s only existing hydropower facility at Ela Dam.

13 HYDRO ENERGY↗

Enhanced Geothermal Shot Analysis for the Geothermal Technologies Office: Preprint

In 2021, the U.S. Department of Energy (DOE) began the Energy Earthshots initiatives to accelerate breakthroughs of reliable clean energy solutions within the next 10 years. In 2022, the National Renewable Energy Laboratory (NREL) was asked by the DOE Geothermal Technologies Office (GTO) to provide analysis for developing Energy Earthshot targets for Enhanced Geothermal Systems (EGS), human-made underground reservoirs that extract thermal energy from the earth for electricity generation and/or heating applications. The Enhanced Geothermal Shot analysis is based on the technology assumptions in the 2019 GTO report GeoVision: Harnessing the Heat Beneath Our Feet. For Earthshot, we updated some of the technology cost and performance assumptions based on recent technology advances and updated the EGS resource potential to include more detailed analysis. We used the updated EGS supply cost curves to forecast the amount of geothermal electricity generation that could be deployed in the US by 2050 using a capacity expansion model. The results were used to develop a cost target for EGS. On September 8th, 2022, the Enhanced Geothermal Shot was announced. Its target - reduce the cost of EGS by 90%, to $45 per megawatt hour by 2035. This paper summarizes the cost and resource assumptions used in the Enhanced Geothermal Shot. It describes the assumptions used in the Regional Energy Deployment System (ReEDS) capacity expansion model to forecast geothermal deployment and discusses the results.

analysis↗

High-Resolution Computed Tomography Dataset of Mount Simon Sandstone

The Illinois Basin is a critical structure for subsurface energy related activities and their implementation in the United States. The Mount Simon Sandstone has been identified as a storage target for permanent and transient storage of fluids in the basin. Known for its exceptional thickness, depth, porosity, and sealing properties of overlying formations, this saline reservoir is crucial for long-term subsurface energy efforts. We present an extensive Computed Tomography (CT) dataset on a high porosity and permeability zone in the lower Mount Simon Sandstone available on the Energy Data eXchange® (EDX). This publicly accessible database comprises over 500 GB of high-resolution CT scans of six core samples, with resolutions ranging from 14.8 µm to 0.7 µm per pixel. The scans include both dry sandstone samples and those saturated with multiple fluids, allowing for comparative analyses across different conditions and resolutions. Coarser scans capture the bedding structure of the sandstone, while finer resolutions reveal detailed pore infill and throat characteristics. Metadata on location, depth, and saturation state enhance usability, enabling quick identification and cross-sample comparisons. By providing a robust resource for research and collaboration, the database contributes to domestic energy advancement by supporting continued progress in the use of the subsurface for energy solutions.

characterization↗

Nuclear-Driven Integrated Energy Systems: A State-of-the-Art Review

Because of the growing concerns regarding climate change and energy sustainability, a transition toward a modern energy sector that reduces environmental effects while promoting social and economic growth has gained traction in recent years. Sustainable energy solutions, which include renewable and low-carbon sources such as nuclear energy and natural gas, could minimize emissions of greenhouse gases, enhance air and water quality, and encourage energy independence. Yet, the shift to a sustainable energy industry is fraught with difficulties, including governmental and regulatory obstacles, technological and economic limits, and societal acceptability hurdles. Addressing these issues would necessitate the development of long-term, durable, and cost-effective energy systems containing nuclear energy and associated with the generation of both electricity and other by-products required by industry. Integrated energy systems (IES) are a novel way to maximize the use of various energy resources and technologies in order to deliver dependable, efficient, and sustainable energy services. IES entail the integration of various energy systems, such as electricity, heating, cooling, and transportation, in respect to energy sustainability and a system’s resilience and flexibility. Their development and implementation require the cooperation of several parties, including energy providers and policymakers. This study provides a state-of-the-art literature review of the most creative nuclear-driven hybrid energy system applications and methodologies, from which the research challenges and prospects for effective IES implementation emerge.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗