Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Energy Development”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46

Remining and Restoring Abandoned US Mining Sites: The Case for Materials Needed for Zero-Carbon Transition

The electricity generation sector is responsible for 25% of the world’s greenhouse gas (GHG) emissions and thus has been the focus of efforts to transition to clean energy and sustainable development in many nations. In the past 20 years, renewable energy sources have been the fastest-growing energy source in the world, comprising almost 29% of the world’s electricity generation in 2020. Renewable energy sources are expected to comprise nearly 95% of the world’s power capacity growth through 2026, with a share of planned capacity expansion of up to 46% in 2026. The rapid development of renewable energy sources and technologies will require an enormous amount of raw materials to replace coal and gas plants and increase in the capacity to handle growing electricity demand because renewable energy sources have a low-power density and intermittent behavior. Accounting for the expected scale of rapidly deploying renewable energy sources that require rare earth elements (REEs), cement, and steel, the mining industry may face a supply problem for the materials critical for clean energy. And, as the exploration and development of new mining sites can be expensive and risky, the mining industry may require economic stimuli to grow supply. The increasing demand for renewable energy resources makes mining a threat to the environment unless proper regulations are established and calls for remining, cleanup, and circular economic development are made. Mining also contributes to environmental injustices related to the exploitation and pollution of lands near communities that are dependent on biodiversity in the area, while not always benefiting from technological advancements provided by the use of renewable energy and technologies. This study explored the opportunity of remining abandoned mining waste to extract metals and minerals essential for the production of renewable energy sources. The authors analyzed materials used in the production of these technologies, materials readily available in the United States, and which materials can be extracted locally in the United States from abandoned mine waste. The authors also studied environmental injustices that populations near mining sites experience and ways to mitigate these injustices, such as providing more control over extraction and cleanup activities, providing more job opportunities in those areas, and offsetting costs associated with cleanup and land restoration projects.

42 ENGINEERING↗

Ultra-Capacitor Energy Storage in a Large Hybrid Electric Bus

The power requirements for inner city transit buses are characterized by power peaks about an order of magnitude larger than the average power usage of the vehicle. For these vehicles, hybrid power trains can offer significantly improved fuel economy and exhaust emissions. A critical design challenge, however, has been developing the energy storage and power management system to respond to these rapid power variations. Most hybrid vehicles today use chemical energy storage batteries to supplement the power from the fuel burning generator unit. Chemical storage batteries however, present several difficulties in power management and control. These difficulties include (1) inadequate life, (2) limited current delivery as well as absorption during regenerative braking, (3) inaccurate measurement of state of charge, and (4) stored energy safety issues. Recent advances in ultra-capacitor technology create an opportunity to address these concerns. The NASA Lewis Research Center, in cooperation with industry and academia, has developed an advanced hybrid electric transit bus using ultra-capacitors as the primary energy storage system. At over 15,000-kg gross weight, this is the largest vehicle of its kind ever built using this advanced energy storage technology. Results of analyses show that the vehicle will match the performance of an equivalent conventionally powered vehicle over typical inner city drive cycles. This paper describes the overall power system architecture, the evolution of the control strategy, and analysis of power flow and vehicle performance.

Viterna, L. A.↗

Hydropower representation in water and energy system models: a review of divergences and call for reconciliation

Abstract Reservoir-based hydropower systems represent key interactions between water and energy systems and are being transformed under policy initiatives driven by increasing water and energy demand, the desire to reduce environmental impacts, and interacting effects of climate change. Such policies are often guided by complex system models, whereby divergence in system representations can potentially translate to incompatible planning outcomes, thereby undermining any planning that may rely on them. We review different approaches and assumptions in hydropower representation in water and energy systems. While the models and issues are relevant globally, the review focuses on applications in California given its extensive development of energy and water models for policy planning, but discusses the extent to which these observations apply to other regions. Structurally, both water-driven and energy-driven management models are similar. However, in energy models, hydropower is often represented as a single-priority output. Water management models typically allocate water for competing priorities, which are generally uninformed by dynamic electricity load demand, and often result in a lower priority for hydropower. In water models, constraints are increasingly resolved for non-energy components (e.g. inflow hydrology and non-energy water demand); few analogues exist for energy models. These limitations may result in inadequate representations of each respective sector, and vastly different planning outcomes for the same facilities between the two different sectors. These divergent modeling approaches manifest themselves in California where poorly reconciled outcomes may affect decisions in hydropower licensing, electricity grid flexibility and decarbonization, and planning for environmental water. Fully integrated water-energy models are computationally intensive and specific to certain regions, but better representation of each domain in respective efforts would help reconcile divergences in planning and management efforts related to hydropower across energy and water systems.

Rheinheimer, David E. (ORCID:0000000315259069)↗

Fighting the climate crisis with caloric heat pumping: Innovations to enable widespread adoption

Caloric heat pumping is a cross-cutting thermal energy technology that can cover a wide range of applications and temperatures, from millikelvins to hundreds of kelvins, with a working medium that has zero global warming potential. The technology promises cost savings and high efficiency, having 60% Carnot efficiency demonstrated to date. The Energy Earthshots™ Initiative, launched by the U.S. Department of Energy, aims to fight the climate crisis and overcome technological barriers to a decarbonized economy. The initiative focuses on the development of energy solutions that increase efficiency, reduce greenhouse gas emissions, and ensure affordability. Three out of eight Energy Earthshots™ look for alternative thermal energy technologies for extensive temperature ranges, from hydrogen liquefaction to metal-treating temperatures. Caloric heat pumping can fulfill all these requirements; however, at the current stage, caloric systems have limited presence in real-world applications. Further, this perspective discusses key efforts to address barriers hindering the widespread adoption of caloric technology. We focus on essential breakthroughs in and effective approaches to material discovery and draw a path to high-power-density, grid-interactive caloric systems to support achieving the ambitious net-zero carbon economy goal.

42 ENGINEERING↗

Energy recovery from solid waste. Volume 1: Summary report

A systems analysis of energy recovery from solid waste which demonstrates the feasibility of several processes for converting solid waste to an energy form is presented. The social, legal, environmental, and political factors are considered and recommendations made in regard to legislation and policy. A technical and economic evaluation of available and developing energy-recovery processes is given with emphasis on thermal decomposition and biodegradation. A pyrolysis process is suggested. The use of prepared solid waste as a fuel supplemental to coal is considered to be the most economic process for recovery of energy from solid waste. Markets are discussed with suggestions for improving market conditions and for developing market stability. A decision procedure is given to aid a community in deciding on its options in dealing with solid waste.

Source record↗

Clouds and the earth's radiant energy system (CERES) - Instrument design and development

Measurements of the earth's reflected shortwave and emitted longwave energy and of the effect of clouds on these quantities are planned using a refined version of the Earth Radiation Budget Experiment (ERBE) scanning instrument. The CERES instruments are being designed to accumulate earth radiance measurements with a repeatability of better than 0.5 percent over their five year life. Beginning in 1996, flights are planned on both polar and low earth orbit satellites to obtain the required temporal and spatial coverage. The design and development of CERES are discussed.

Kopia, Leonard P.↗

Pilot Development Progress to Demonstrate Electric Thermal Energy Storage (ETES) Using Low-Cost Particles

The rapid growth of future energy demand increases the need to economically store electrical energy over durations up to several days in long-duration energy storage (LDES) applications. LDES can reduce the grid stress for improving the resilience of the grid. The integration of renewable power and storage has several significant and positive impacts including expanding the renewable energy portion of electricity generation, meeting peak-load demand, and coordinating supply and demand. Several energy storage approaches including mechanical, chemical and electrochemical methods are currently deployed or under development. However, LDES requirements pose unique challenges for scalability, energy capacity, and cost. Thermal energy storage (TES) has the ability to store a large capacity of energy with improved site flexibility compared to incumbent LDES technologies (i.e., pumped hydro) and has attracted significant interest. Our development in TES technology using solid particles as the storage medium has shown feasibility and potential in serving LDES purposes. Particle TES has various advantages over commercialized molten nitrate salt TES and has emerged as a promising storage technology originating from Generation 3 concentrating solar power (CSP) development. Stable, inexpensive silica sand produced in the Midwestern U.S. was identified as a suitable storage medium and has been validated through lab heating and cycling tests. We have successfully developed particle TES for bidirectional electric energy storage to broaden the applications for TES beyond CSP technologies and into standalone electric-thermal energy storage (ETES) systems. Key component designs and performance were verified with prototype testing and model simulations. The ETES system uses high-temperature, low-cost particle thermal energy storage coupled with a unique pressurized fluidized bed heat exchanger that supports a high-efficiency, air-Brayton combined power cycle. At times of low energy demand or high renewable production, an electric particle heater heats large quantities of solid particles to high temperatures in excess of 1100 degrees C. The particles are stored in internally insulated silos. At times of high electricity demand, the hot particles are gravity-fed through the heat exchanger where stored thermal energy is transferred to the power cycle working fluid to drive the gas turbine power generation system, thereby converting the thermal energy back into electricity for the grid. The cold particles leaving the heat exchanger are returned to the storage silos by a well-insulated particle conveyor. This ETES technology using particle TES can be sited anywhere and is predicted to be economic and efficient. Moreover, this ETES technology could be co-located with a retired coal or gas plant to leverage existing power generation and grid infrastructure. Our work has focused on the development of each of the key components (e.g., the electric particle heater, particle storage silos, and the particle-to-gas pressurized fluidized bed heat exchanger) through conceptual designs, prototype testing, and computational modeling. These developments demonstrate technological feasibility and are an important step towards the next phase of development of this promising LDES technology. This presentation will show the progress in developing a pilot demonstration of the ETES system on a commercially relevant scale.

25 ENERGY STORAGE↗

Understanding the Uncertainty in the Technical Performance Level Assessment for Wave Energy

In recent years, the design and development of wave energy converters (WECs) has been explored with intense interest, with highly varying design concepts emerging globally across both research enterprises and industry. The design space for WECs is vast - many concepts ranging in functionality, control systems, power development systems, materials, and scale have been ideated and prototyped, but WEC technology has yet to converge. One critical element of the technology trajectory that governs the speed of adoption is the performance of a WEC concept. In analogous but more-established industries (such as aerospace, and environmentally sustainable electronics design), performance assessment is a quantitative method, based on historical data, that is used as an iterative tool to improve the design of these systems early on in the design process. Though more nascent than these approaches, in wave energy R&D, WEC performance has been assessed using the Technology Performance Level (TPL) assessment, which provides designers with a quantitative score, situating a grid-scale WEC concept on a scale from 1-9 (1 being the lowest performance, and 9 being the highest, trending with the oft-used Technology Readiness Level, or TRL). The TPL assessment is designed to be used during design iteration, when a WEC concept is fully ideated, to enable designers to consider potential means of improving the downstream performance of the concept. One concern that may be slowing the adoption of TPL among WEC developers is the inherent uncertainty in the assessment, and how uncertainty in the individual questions asked as part of the assessment may contribute to perceived inaccuracies in the final score. In this work, we explore the uncertainty present in the assessment and quantify this uncertainty using both traditional mathematical operations and a Monte Carlo simulation. Results imply areas of improvement of the TPL assessment, where reducing uncertainty will be most helpful to end users, enabling both TPL practitioners and users to understand with more accuracy those design elements that can be improved to impact device performance most substantively.

techno-economic analysis↗

The U.S.-NSF/NASA

The five-year research and development plan of the NSF/NASA Wind Energy Conversion Systems (WECS) program is outlined. The program includes mission studies to determine energy use patterns and requirements and define specific applications for wind energy systems, wind energy resource assessment and development, and development of cost-effective components and subsystems. The program is also directed towards the development of energy storage systems to make wind powered systems firm power sources where appropriate. A 100 kW experimental wind generator (Model Zero) is being designed as a flexible test bed for a variety of system components. Designs will be developed for units in the 50 to 200 kW and 500 to 3000 kW size ranges.

Source record↗

High‐Energy‐Density Chelated Chromium Flow Battery Electrolyte at Neutral pH

Abstract High‐concentration operation of redox flow batteries (RFBs) is essential for increasing their energy‐storage capacity, but non‐acidic electrolytes struggle to achieve the high concentrations of metal ions dissolved in acid, limiting the development of energy‐dense neutral pH electrolytes. We report neutral pH RFB operation of chromium 1,3‐propylenediaminetetraacetate (CrPDTA) at concentrations of 1.2 M at room temperature and 1.6 M at 40 °C, demonstrating 60% higher negolyte capacity, up to 42.9 Ah L −1 , than previously reported for non‐additive‐utilizing solutions of this promising material. With extended full cell cycling, we demonstrate the importance of buffer selection and pH when using the Fumasep E‐620(K) membrane. Finally, we expand the pH operation range of CrPDTA to pH 7, which when cycled at 100 mA cm −2 against a ferrocyanide posolyte demonstrated excellent coulombic efficiencies >99.7% and energy efficiencies >87%, while operating at almost 700 mV more negative than the thermodynamic hydrogen evolution window.

Chemistry↗

As a Matter of Tension: Kinetic Energy Spectra in MHD Turbulence

While magnetized turbulence is ubiquitous in many astrophysical and terrestrial systems, our understanding of even the simplest physical description of this phenomena, ideal magnetohydrodynamic (MHD) turbulence, remains substantially incomplete. As such, in this work we highlight the shortcomings of existing theoretical and phenomenological descriptions of MHD turbulence that focus on the joint (kinetic and magnetic) energy fluxes and spectra by demonstrating that treating these quantities separately enables fundamental insights into the dynamics of MHD turbulence. This is accomplished through the analysis of the scale-wise energy transfer over time within an implicit large eddy simulation of subsonic, super-Alfvénic MHD turbulence. Our key finding is that the kinetic energy spectrum develops a scaling of approximately k –4/3 in the stationary regime as magnetic tension mediates large-scale kinetic to magnetic energy conversion and significantly suppresses the kinetic energy cascade. This motivates a reevaluation of existing MHD turbulence theories with respect to a more differentiated modeling of the energy fluxes.

79 ASTRONOMY AND ASTROPHYSICS↗

Thermal Remote Sensing: A Powerful Tool in the Characterization of Landscapes on a Functional Basis

Thermal remote sensing instruments can function as environmental measuring tools, with capabilities leading toward new directions in functional landscape ecology. Theoretical deduction and phenomenological observation leads us to believe that the second law of thermodynamics requires that all dynamically systems develop in a manner which dissipates gradients as rapidly as possible within the constraints of the system at hand. The ramification of this requirement is that dynamical systems will evolve dissipative structures which grow and complexify over time. This perspective has allowed us to develop a framework for discussing ecosystem development and integrity. In the context of this framework we have developed measures of development and integrity for ecosystems. One set of these measures is based on destruction of the exergy content of incoming solar energy. More developed ecosystems will be more effective at dissipating the solar gradient (destroying its exergy content). This can be measured by the effective surface temperature of the ecosystem on a landscape scale. These surface temperatures are measured using airborne thermal scanners such as the Thermal Infrared Multispectral Scanner (TIMS) and the Airborne Thermal/Visible Land Application Sensor(ATLAS) sensors. An analysis of agriculture and forest ecosystems will be used to illustrate the concept of ecological thermodynamics and the development of ecosystems.

Jeffrey, Luvall C.↗

Energy Systems Integration Facility Stewardship Summary: Fiscal Year 2024

A summary of NREL's good stewardship of the nationally unique Energy Systems Integration Facility (ESIF) highlighting performance metrics, infrastructure upgrades, and examples of R&D impact. In fiscal year 2024, we developed advanced energy security and resilience capabilities as we built a new test bed for power electronics and completed a 1-megawatt platform for studying energy systems with grid-forming inverters. Researchers collaborated with utilities, manufacturers, and communities to solve their pressing questions, such as a control architecture that heralds a new direction for distributed energy management systems. With support from the U.S Department of Energy (DOE), the work in the ESIF laboratories continues to advance national goals for resilient and affordable energy.

annual report↗

A view from the AIAA: Introduction of new energy storage technology into orbital programs

The development of new energy storage technology must be heavily weighted toward the application. The requirements for transitioning low risk technology into operational space vehicles must remain the central theme even at the preliminary development stages by the development of efforts to define operational issues and verify the reliability of the system. Failure to follow a complete plan that results in a flight qualified unit may lead to an orphan technology. Development efforts must be directed toward a stable development where changes in design are evolutionary and end items are equivalent to flight units so that life and qualification testing can be used as a vehicle to demonstrate the acceptability of the technology.

Badcock, Charles↗

Asymmetric Lattice Disorder Induced at Oxide Interfaces

Control of order-disorder phase transitions is a fundamental materials science challenge, underpinning the development of energy storage technologies such as solid oxide fuel cells and batteries, ultra-high temperature ceramics, and durable nuclear waste forms. At present, the development of promising complex oxides for these applications is hindered by a poor understanding of how interfaces affect lattice disordering processes and defect transport. Here we explore the evolution of local disorder in ion-irradiated La 2 Ti 2 O 7 /SrTiO 3 thin film heterostructures using a combination of high-resolution scanning transmission electron microscopy (STEM), position-averaged convergent beam electron diffraction (PACBED), electron energy loss spectroscopy (STEM-EELS), and ab initio theory calculations. We observe highly non-uniform lattice disordering driven by asymmetric oxygen vacancy formation across the interface. Our calculations indicate that this asymmetry results from differences in the polyhedral connectivity and vacancy formation energies of the two interface components, suggesting ways to manipulate lattice disorder in functional oxide heterostructures.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Strategic Energy Plan: Playa de Ponce, Ponce, Puerto Rico

Un Nuevo Amanecer Inc. (UNA), a community-based NGO (501C(3)), sought technical assistance through the U.S. Department of Energy's (DOE's) Energy Technology Innovation Partnership Project (ETIPP) to develop a strategic energy plan (SEP) for the community of Playa de Ponce on the south coast of Puerto Rico. A SEP helps communities identify energy goals and priority projects, and outline strategies and actions to build a shared path toward their energy vision. The primary goal of this SEP is to collaboratively explore pathways for the community's energy future. Researchers from the National Laboratory of the Rockies (NLR) engaged with the community for a period of seven months and facilitated a series of in-person community engagement workshops along with ETIPP regional partner Puerto Rico Hispanic Federation, UNA, and community leaders. The SEP workshops were held twice, March 18-20 and June 24-26, 2025. Through facilitated discussions, the community worked together to define and articulate a clear vision for its short-, medium-, and long-term energy goals. The workshops played a key role in identifying the specific strategies and priority projects that would best suit the needs of the community. The discussions outlined the community's energy aspirations, establishing a shared vision, setting goals, and outlining the priority actions needed to bring them to fruition. During the workshops, the community shared some of the most pressing energy challenges that they face on a regular basis, such as high energy costs that disproportionately impact an aging population and unreliable electricity during extreme weather events that result in frequent power outages. These issues have also exacerbated risks to public health and safety of the community. In response, UNA requested technical assistance through ETIPP to inform the development of a SEP tailored to Playa de Ponce to support its energy vision. This document explores four community-driven energy strategies aligned with that vision. Figure 1 shows the strategies outlined in this plan, which are categorized into three focus areas as identified by the community: energy reliability; safety and security; and stakeholder participation, education, and capacity building. This document serves as a shared roadmap for developing and implementing energy solutions that meet the needs of Playa de Ponce. It is intended to serve as a public resource for the community, UNA, and local authorities - providing tools, information and a shared foundation to inform future implementation efforts. This plan is intended to complement ongoing planning frameworks at the municipal, regional, and island-wide levels. As a living document, this SEP can evolve alongside Playa de Ponce's changing energy goals, while offering a framework to help them realize their energy vision.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Energy Storage Impacts in Resilience Hubs and Other Critical Infrastructure: An Assessment Guide for Developers and Practitioners

Battery energy storage systems (BESS) deployed behind the meter at resilience hubs and other critical infrastructure can provide economic and operational value during normal operations—such as lower and more predictable energy costs—as well as resilience and security benefits during power disruptions by maintaining essential services. However, existing evaluation approaches tend to focus narrowly on engineering performance or rely on broad socio-economic frameworks that are not well suited to behind-the-meter storage. As a result, developers, utilities, and funders often lack consistent methods for defining success, quantifying benefits, and comparing outcomes across projects. This report presents a practitioner-oriented impact assessment framework for evaluating behind-the-meter BESS at resilience hubs and critical infrastructure facilities. The framework is organized into five iterative components—developing an action plan, defining project goals, identifying metrics, collecting data and measuring outcomes, and reporting and using results—and includes a structured metric architecture spanning six impact categories. Designed for real-world constraints such as limited staffing and uneven data availability, the framework was developed, applied, and refined through real projects, and is illustrated with case studies across diverse deployment contexts.

Impact Assessment↗