SEARCH · Engineering Papers

Results for “high renewable”

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.

SourceResearch connectionFrom yearThrough year

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

At least 541 records · Page 30

All sources NASA NTRS DOE OSTI

DOE OSTI2021

Dual function materials (Ru+Na 2 O/Al 2 O 3 ) for direct air capture of CO 2 and in situ catalytic methanation: The impact of realistic ambient conditions

Here a dual function material (DFM) comprised of 1% Ru, 10% Na 2 O/γ–Al 2 O 3 was studied for combined direct air capture (DAC) of CO 2 and catalytic methanation in a temperature swing operation. In the newly proposed operation, the DFM captures CO 2 (400 ppm) from air at ambient conditions. The material is then heated in H 2 to a temperature sufficient for catalytic conversion of the captured CO 2 to renewable natural gas. In this study, we demonstrate high CO 2 adsorption capacity and rates at ambient conditions (25 °C); the adsorbed CO 2 is then successfully catalytically methanated upon heating in H 2 . Adsorption was also carried out in humid conditions, more closely simulating ambient air. Adsorption and methane production were greatly improved with stable initial performance. The rate of adsorption is shown to be flowrate-dependent, which is critical for future reactor design.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2026

Green pretreatment strategies for enhanced microbial lipid fermentation and synergistic high-quality lignin recovery for next-generation integrated biorefineries

Miscanthus × giganteus (Mxg) is a warm-season perennial grass being commercialized as a biomass feedstock for temperate farms. Three process strategies were compared for converting Mxg into single-cell oil and extracted lignin intermediates, as hydrothermal (HT) processing and two natural deep eutectic solvents (NADES), ChCl:LA (choline chloride:lactic acid) and ChCl:Gly (choline chloride:glycerol). Pretreatments were performed at 10% and 50% solids loading at 140 °C, 2 h; HT: 190 °C, 10 min. Enzymatic hydrolysates, generated at 10% solids using washed and unwashed biomass, were evaluated for microbial lipid production. Maximum glucose conversions from washed biomass reached 83.5% (ChCl:LA), 52.7% (ChCl:Gly), and 74.0% (HT). Remarkably, NADES-derived hydrolysates effectively replaced refined sugars for the cultivation of the oleaginous yeast Rhodotorula toruloides, achieving ∼51% higher biomass (OD 90.7) and lipid titers of 19.36 g/L within 45 h using a two-stage fermentation strategy. Lipid contents ranged from 34.5–44.5% dry weight, demonstrating reduced reliance on purified sugars. Beyond carbohydrate valorization, ChCl:LA pretreatment enabled high-purity lignin recovery (>89%) in a lignin-first strategy. Structural analyses (2D-HSQC and ³¹P NMR) showed syringyl (78.15%), guaiacyl (15.15%), and p-hydroxyphenyl (6.41%) units, with higher phenolic hydroxyl content (0.91 mmol/g) and a lower S/G ratio (0.19) than HT lignin (0.87 mmol/g, S/G 0.22). These attributes favor downstream lignin depolymerization into low-molecular-weight aromatics. Overall, NADES pretreatment simultaneously enhances microbial lipid yields and recovers high-quality lignin, advancing the economic feasibility of renewable diesel and sustainable aviation fuel (SAF) production from bioenergy crops within an integrated biorefinery framework.

2D HSQC↗

DOE OSTI2021

Performance and cost analysis of liquid fuel production from H 2 and CO 2 based on the Fischer-Tropsch process

Electro-fuels can be produced from concentrated sources of carbon dioxide and hydrogen using electricity generated from renewable sources; this process enables energy storage at high volumetric energy density. Among the electro-fuels options, FT (Fischer-Tropsch) fuel is attractive for heavy-duty trucks and non-road transportation applications. This study conducts a techno-economic analysis of FT liquid fuel production from H 2 and CO 2 using a detailed performance analysis. Minimum fuel selling price is estimated for a broad range of H 2 and CO 2 prices and for a range of potential CO 2 credits. The analysis indicates that H 2 price has the largest impact on the minimum selling price of FT fuel. FT fuel production with a CO 2 price of $17.3/metric ton requires an H 2 price of $0.8/kg to be cost-competitive with the pre-tax petroleum diesel price of $3.1/gal in 2050 (before the application of any CO 2 credits). When the H 2 price is $2.0/kg from central water electrolysis (2020 target), the minimum selling price of the FT fuel is $5.4–5.9/gal. A sensitivity analysis shows that future system optimization of FT fuel production could focus on improving the H 2 and CO 2 recycle contributions and FT fuel conversion ratio. The analysis results can be combined with various upstream systems for H 2 and CO 2 production.

08 HYDROGEN↗

DOE OSTI2023

Evaluation of distributed process-based hydrologic model performance using only a priori information to define model inputs

Fully distributed, integrated surface–subsurface hydrological models (ISSHMs) have seen renewed interest due to availability of better software, high performance computing facilities, and high-resolution, spatially extensive data products. ISSHMs are valuable as tools for advancing system understanding as they can resolve multiple processes defined on the plot scale including three-dimensional interaction of surface water and groundwater. Here, we evaluated the performance of an ISSHM, the Advanced Terrestrial Simulator (ATS), on seven diverse catchments across the continental US using widely available data products to define model inputs without calibration. We compare the ATS-simulated streamflow and evapotranspiration with gauge observations and MODIS-derived evapotranspiration, respectively. Using the Kling-Gupta Efficiency (KGE) as metric, ATS with default data products performed reasonably well at 6 of 7 catchments for streamflow. However, in one of those 6 catchments ATS had poor performance on baseflow and ATS’s overall performance was thus judged to be inadequate despite the acceptable KGE. ATS performance for evapotranspiration was good in all 7 catchments using default data products. In the two catchments where ATS streamflow performance using default data products was not acceptable, the performance was significantly improved by using local information on subsurface properties below the soil. We also compare the model-simulated streamflow and evapotranspiration with the Sacramento soil moisture accounting (SAC-SMA) model, a semi-distributed model that was calibrated on a catchment-by-catchment basis. Uncalibrated ATS performance is comparable to the calibrated SAC-SMA model in terms of streamflow while ATS performance is similar to or better (much better in certain catchments) in reproducing MODIS-derived evapotranspiration. Reasonably good performance of ATS without catchment-specific calibration provides new confidence in the ISSHM class of models and community data products as tools for advancing understanding of watershed function in a changing environment.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2020

Role of Silica Support in Phosphoric Acid Catalyzed Production of p -Xylene from 2,5-Dimethylfuran and Ethylene

p-Xylene is a commodity chemical of industrial importance for terephthalic acid production, for which renewable sourcing from naturally abundant lignocellulosic biomass is highly desired. Previous work demonstrated that phosphoric acid stabilized on siliceous zeolite supports (e.g., P-BEA, P-SPP) exhibits high selectivity toward p-xylene (>97%) from 2,5-dimethylfuran (DMF) and ethylene. However, the effect of the support and the contribution of heterogeneous versus homogeneous phosphoric acid on the observed catalytic behavior in the solvated reaction system have not been addressed. Here, we determine the phosphoric acid catalytic activity for DMF conversion and its selectivity to p-xylene when it is supported on a silica support as well as in the absence of a support. Specifically, phosphoric acid catalysis was studied in three different scenarios: (1) phosphoric acid was added in the liquid reaction mixture in the absence of any solid support, (2) phosphoric acid was added in the liquid reaction mixture along with inert silica support including siliceous zeolite (i.e., allowing for phosphoric acid–support assembly to proceed in the reaction mixture), and (3) phosphoric acid was first impregnated on the siliceous zeolite support and then the preassembled supported phosphoric acid catalyst was added in the liquid reaction mixture. We found that the reaction rate and selectivity to p-xylene are different in the above scenarios reflecting the effect of the solid support on the catalytic performance of phosphoric acid. In scenario 1, a low concentration of phosphoric acid (1.7 mM) in the absence of any solid support exhibited high selectivity to p-xylene (80% selectivity to p-xylene at 60% conversion of DMF), which decreased with increasing acid concentration. The selectivity to p-xylene and activity of phosphoric acid significantly increased by adding a silica support into the reaction system (scenario 2). Furthermore, this improvement was attributed to phosphoric acid partial association with the surface of the silica support under the reaction conditions (in situ catalyst assembly). Phosphoric acid predeposited on siliceous zeolite supports (e.g., P-BEA, P-SPP) synthesized via impregnation prior to the reaction (scenario 3) catalyzed the reaction heterogeneously without noticeable leaching and exhibited the highest activity and selectivity to p-xylene, suggesting an important role of the silica support and the need to ensure that phosphoric acid acts as a heterogeneous catalyst in order to accomplish selective conversion of DMF to p-xylene.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2025

Locally Confined Polysulfide-Reactive Electrolytes for Shuttle-Free Sodium–Sulfur Batteries

Sodium-sulfur batteries promise high-energy-density and sustainable electrochemical energy storage but suffer from uncontrolled polysulfides dissolution and high sodium reactivity. These challenges fundamentally originate from poor electrolyte-electrode compatibility. Current electrolyte research inadequately addresses the trade-off between minimal polysulfides solvation and stabilizing sodium interfaces. Here, we present a locally-confined polysulfide-reactive electrolyte strategy that mediates the polysulfide dissolution dynamics and sodium stability by leveraging an electrophilic solvating species with a localized high-concentration electrolyte. This design enables shuttle-free cell operation by synergistically restricting the global solvating power of the electrolyte through intermolecular interactions and locally scavenging sparingly dissolved polysulfides via electrolyte electrophilicity. The precisely confined surface reaction facilitates a protective cathode-electrolyte interface, realizing a quasi-solid-state sulfur conversion in our liquid ether-based electrolyte, which crucially avoids crossover-induced catastrophic sodium-metal degradation. The proposed electrolyte demonstrates long-term cycling of high-mass-loading sulfur cathodes (> 3 mg S cm −2 with commercial carbon host and 70 wt% sulfur content), which afford 710 mA h g −1 over 400 cycles in coin cells and steady pouch cell operation over 180 cycles. Furthermore, this work establishes a scalable electrolyte design protocol that regulates the reaction chemistry of highly reactive electrodes, offering a pathway toward sustainable renewable energy storage.

25 ENERGY STORAGE↗

DOE OSTI2023

Harmonized geospatial data to support infrastructure siting feasibility planning for energy system transitions

Climate change, energy system transitions, and socioeconomic change are compounding influences affecting the growth of electricity demand. While energy efficiency initiatives and distributed resources can address a significant amount of this demand, the United States will likely still need new utility-scale generation resources. The energy sector uses capacity expansion planning models to determine the aggregate need for new generation, but these models are typically at the state or regional scale and are not equipped to address the wide range of location- and technology-specific issues that are increasingly a factor in power plant siting. To help address these challenges, we have developed the Geospatial Raster Input Data for Capacity Expansion Regional Feasibility (GRIDCERF) data package, a high-resolution product to evaluate siting suitability for renewable and non-renewable power plants in the conterminous United States. GRIDCERF offers 264 suitability layers for use with 56 power plant technologies in a harmonized format that can be easily ingested by geospatially-enabled modeling software allowing for customization to robustly address science objectives when evaluating varying future conditions.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2021

Magnetic and f-electron effects in LaNiO2 and NdNiO2 nickelates with cuprate-like $$3{d}_{{x}^{2}-{y}^{2}}$$ band

Recent discovery of superconductivity in the doped infinite-layer nickelates has renewed interest in understanding the nature of high-temperature superconductivity more generally. The low-energy electronic structure of the parent compound NdNiO 2 , the role of electronic correlations in driving superconductivity, and the possible relationship between the cuprates and the nickelates are still open questions. Here, by comparing LaNiO 2 and NdNiO 2 systematically within a parameter-free, all-electron first-principles density-functional theory framework, we reveal the role of Nd 4 f electrons in shaping the ground state of pristine NdNiO 2 . Strong similarities are found between the electronic structures of LaNiO 2 and NdNiO 2 , except for the effects of the 4 f electrons. Hybridization between the Nd 4 f and Ni 3 d orbitals is shown to significantly modify the Fermi surfaces of various magnetic states. In contrast, the competition between the magnetically ordered phases depends mainly on the gaps in the Ni $3{d}_{{x}^{2}-{y}^{2}}$ band. Our estimated value of the on-site Hubbard U in the nickelates is similar to that in the cuprates, but the value of the Hund’s coupling J H is found to be sensitive to the Nd magnetic moment. In contrast with the cuprates, NdNiO 2 presents 3D magnetism with competing antiferromagnetic and (interlayer) ferromagnetic exchange, which may explain why the T c is lower in the nickelates.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Evaluating the Potential for Tidal Phase Diversity to Produce Smoother Power Profiles

Although tidal energy conversion technologies are not yet commercially available or cost-competitive with other renewable energy technologies like wind turbines and solar panels, tides are a highly predictable resource. Tidal energy’s predictability indicates that the resource could introduce less volatility into balancing the electric grid when compared to other renewables, a fundamentally desirable attribute for the electric system. More specifically, tidal energy resources are unique in that they have the potential to produce relatively smoother power profiles over time through aggregation. In order to generate smooth power profiles from tidal resources, sufficient complexity within the timing of tides is necessary within electrical proximity. This study evaluates the concept of aggregating diverse tides for the purpose of reducing periods of no and low energy production and creating smoother power profiles in regions around Alaska and Washington by calculating cross-correlations of tidal current velocity time series. Ultimately, study results show limited potential to exploit the resources for this purpose and describe the institutional mechanisms necessary to realize the benefits in practice.

16 TIDAL AND WAVE POWER↗

DOE OSTI2024

GRIDCERF - Geospatial Raster Input Data for Capacity Expansion Regional Feasibility

The Geospatial Raster Input Data for Capacity Expansion Regional Feasibility (GRIDCERF) data package is a high-resolution product to evaluate siting suitability for renewable and non-renewable power plants in the conterminous United States. GRIDCERF offers hundreds of individual suitability layers for use with both renewable and non-renewable power plant technology configurations in a harmonized format that can be easily ingested by geospatially-enabled modeling software. It also provides pre-compiled technology-specific suitability layers and allows for user customization to robustly address science objectives when evaluating varying future conditions. GRIDCERF data can be directly used with the CERF (Capacity Expansion Regional Feasibility) model to site power plants at a 1km resolution. GRIDCERF includes composite technology siting suitability raster layers for the following utility scale technology configurations. Note that, in addition to technology sub-types shown below, various cooling types are also included (recirculating, pond, once-through, recirculating-seawater, dry-hybrid, or dry) for various technologies. Biomass Conventional (with or without CCS) IGCC (with or without CCS) Coal Conventional (with or without CCS) IGCC (with or without CCS) Natural Gas Combined-cycle (CC) (with or without CCS) Turbine Geothermal Enhanced Geothermal Systems (EGS) - Class 1 through Class 5 resource potential Nuclear Gen 2 Light Water Reactor (LWR) Gen 3 Small Modular Reactor (SMR) Gen 3 AP1000 Refined Liquids Combined-cycle (CC) (with or without CCS) Turbine Solar Photovoltaic (PV) - for capacity factors in the range of 6-18% Utility-scale Concentrating Solar Power (CSP) - for capacity factors in the range of 24-46% Tower Wind (Onshore) - for capacity factors in the range of 5-50% 80m hub height 100m hub height 120m hub height 140m hub height Wind (Offshore) - for capacity factors in the range of 25-60% 100m hub height 140m hub height 160m hub height

capacity expansion↗

DOE OSTI2026

GRIDCERF - Geospatial Raster Input Data for Capacity Expansion Regional Feasibility

capacity expansion↗

DOE OSTI2020

Deep Retrofits for Multifamily: Experiences in Scaling to Zero Energy: Preprint

Zero net energy (ZNE) buildings are needed to reverse the growing trend of increasing energy consumption. But to make dramatic changes, existing buildings must be renovated at scale. In addition, the building stock must be electrified so that its energy needs could be met by renewable generation. Such aggressive goals often mean very high custom design and capital construction costs. Suitable options for comprehensive envelope retrofits can be too expensive to be practical, and electrification requires upgrades to building-level electrical infrastructure. This paper is a case study of eight projects—primarily multifamily residential—that strived for zero-energy, all-electric retrofits. The design teams were challenged to create solutions that could be replicated at scale, showing decreasing costs with broader adoption. Key technologies considered in designing cost-effective, scalable solutions include industrialized prefabricated retrofit components, modular HVAC solutions, and innovative domestic hot water systems. We trace the progress toward the goals set and examine the choices made by the teams as they encountered technical, logistical, and cost barriers. We also discuss financial challenges for multifamily retrofits, provide guidance for incentives, and examine procurement processes for design services and technologies.

ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION↗

DOE OSTI2021

Key Findings from LA100

This document describes high-level findings from the Los Angeles 100% Renewable Energy Study (LA100), a partnership between the Los Angeles Department of Water and Power (LADWP) and the National Renewable Energy Laboratory (NREL) to analyze potential pathways LA can take to achieve a 100% clean energy future. This is an excerpt of the LA100 Executive Summary (NREL/TP-6A20-79444-ES), which provides additional background and detail.

100% renewable energy↗

DOE OSTI2024

Recognizing Institutions that Prepare Students for 21st Century Building Careers

Buildings play a significant role in reaching the White House's goal of a net-zero emissions economy by 2050, so it is critical that building professionals are prepared to design and construct high-efficiency, low-carbon buildings powered by renewables. The U.S. Department of Energy's Zero Energy Design Designation recognizes post-secondary academic programs that prepare students for 21st century building careers. ZEDD is a three-year designation, and as of 2023 almost 40 programs of study from more than 25 institutions have been recognized and supported by DOE for their great work. The University of Cincinnati received the ZEDD designation for the Net Zero Energy Design Track in Architectural Engineering Program. Tracks, majors, minors, and certificates are all eligible for ZEDD. In recent interviews with faculty from the University of Cincinnati and Appalachian State University about their experiences with ZEDD, many common topics came up. Both faculty members mentioned their students who graduate with ZEDD on their resume are often the only people in their future design firms who understand and can create net zero energy designs.

buildings↗

DOE OSTI2023

Frequency Resilience Enhancement for Power Systems with High Penetration of Grid-Forming Inverters

Abstract—Grid following inverter-based renewable generation has replaced conventional generation in recent years, resulting in lower system inertia. The frequency resilience in such a lower inertia system is critical for emergency mitigation. In this paper, we propose a resilience metric based on frequency recovery to quantitatively represent system resilience in terms of the rate of change of frequency. Application of grid-forming converters provides a means to improve system resilience by providing virtual inertia. An under-frequency load shedding strategy is applied to further support frequency recovery in cases with high penetration of grid-forming inverters. Case studies are designed and performed in a modified IEEE 9-bus test system using the PSCAD/EMTDC platform. Simulation results demonstrate the validity of the proposed resilience metric and the effectiveness of the strategy for reducing frequency excursion in inverter-based power systems. citation: J. Gui, H. Lei, T. R. McJunkin and B. K. Johnson, "Frequency Resilience Enhancement for Power Systems with High Penetration of Grid-Forming Inverters," 2023 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT), Washington, DC, USA, 2023, pp. 1-5, doi: 10.1109/ISGT51731.2023.10066357.

14 SOLAR ENERGY↗

DOE OSTI2022

Renewable low viscosity polyester-polyols for biodegradable thermoplastic polyurethanes

In the transition to renewably sourced, biodegradable polymers, the preparation of low viscosity polyester-polyols has posed a challenge for renewable polyurethane (PU) development. Low viscosity polyols not only reduce the requirement for high process temperatures but also decrease manufacturing time. In our efforts to incorporate increasing ratios of bio-based monomers into renewable PUs, we mixed diacids such as even carbon sebacic acid and odd carbon azelaic acid along with a renewable diol. This provided library of 2000 g/mol molecular weight polyester-polyols, and structures were established by 1 H and 13 C NMR analysis. The prepared polyester-polyols offered lower viscosity and enable lower fabrication temperatures to make TPUs, and their structure and material metrics were evaluated. The formation of TPUs is ascertained from FTIR and NMR analysis. The final TPUs displayed good physical and mechanical properties. Further, these TPUs exhibited T g in the range of -56.5 to -39.7°C, corresponding to TPU soft block structure, and T m between 98.3 and 105.1°C originating from the hard segment. Prepared TPUs exhibit excellent biodegradation under compost environmental conditions. These TPUs showed up to 57% decrease in molecular weight by GPC analysis after 9 weeks of biodegradation, and respirometer analysis displayed up to 97% biodegradation over 120 days.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2025

Second-generation downscaled earth system model data using generative machine learning

The second-generation Sup3rCC dataset provides high-resolution meteorological data generated through the downscaling of multiple earth system models (ESMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6). This downscaling is performed through application of a generative machine learning approach called Super-Resolution for Renewable Resource Data (sup3r). This dataset builds on the first-generation Sup3rCC data by applying improved bias correction methods and adding downscaled precipitation to the output variables. As with the first Sup3rCC version, the data still include temperature, wind speed and direction at multiple heights, pressure, three components of downwelling solar radiation, and relative humidity—all at 4-kilometer (km) hourly resolution over the contiguous United States. This is a 25x spatial enhancement and 24x temporal enhancement of the source 100-km daily-average ESM data. This extension of the Sup3rCC dataset includes data from six ESMs from two shared socioeconomic pathways (SSPs) totaling 400 years of data with multiple future projections of changing meteorological conditions. The scenario selection was based on a structured evaluation of historical ESM skill and comprehensive representation of possible trajectories of future climate change in temperature, humidity, precipitation, solar irradiance, and near-surface wind speeds. The inclusion of multiple future projections is intended to enable users to assess key drivers of un 36 certainty and variability. All data are double-bias corrected, resulting in a product that can be used out-of-the-box for energy system analysis with minimal historical bias. The potential applications of Sup3rCC data extend to various topics in renewable energy resource assessment, energy systems modeling, and grid resilience studies. High-resolution future meteorological projections are critical for evaluating the effects of changing meteorological conditions on renewable energy generation, energy demand, and for optimizing energy storage and grid infrastructure. The 4-km hourly resolution of the downscaled data enables understanding of spatial and temporal variability at the scales necessary for energy system operational planning. In addition, the dataset can support risk assessments by providing detailed information on possible future extreme weather events and long-term meteorological variability at scales relevant to energy infrastructure. By offering an enhanced representation of possible future meteorological conditions, the second-generation Sup3rCC dataset enables more precise modeling of energy resilience and adaptation strategies in response to changing meteorological conditions.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2020

Effects of Peptide-Functionalized Surfaces on the Electrochemical Hydrogen Evolution Reaction

Abstract This review outlines the approaches and mechanisms through which peptides and amino acids functionalize electrocatalytically active surfaces to promote or inhibit the electrochemical hydrogen evolution reaction (HER). HER is important in many electrochemical systems. For example, HER is highly desired in water electrolysis, which if driven by renewable energy could serve as a green alternative to the fossil-fuel-driven steam methane-reforming process. However, HER is often an undesired side reaction and thus limits the selectivity of promising electrochemical technologies such as electrochemical nitrogen reduction or carbon dioxide reduction. In pursuing higher product selectivity and yield in emerging and existing electrochemical systems, amino acids and short-chain peptides are promising molecules for the modification of electrochemically active surfaces. Peptides are attractive because they are highly tunable, which allows for versatility in their applications. This short review article summarizes literature that illustrates the mechanisms through which electrode-bound peptides can affect HER including via modulating surface binding and adsorbate coverage, altering the surface composition, and controlling proton transfer rates. Our goal is to motivate additional studies utilizing electrode-bound peptides to modulate electrochemical hydrogen evolution reactions.

Electrochemistry↗