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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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

The effect of building retrofit measures on CO2 emission reduction – A case study with U.S. Medium office buildings

Building retrofit has great potential to reduce CO2 emissions since buildings are responsible for 36% of emissions in the United States. Several existing studies have examined the effect of building retrofit measures on CO2 emission reduction. However, these studies oversimplified emission factors of electricity by adopting constant annual emission factors. This study uses hourly emission factors of electricity to analyze the effect of building retrofit measures on emission reduction using U.S. medium office buildings as an example. We analyzed CO2 emission reduction effects of eight building retrofit measures that related to envelop and mechanical system in five locations: Tampa, San Diego, Denver, Great Falls, and International Falls. The main findings are: (1) estimating CO2 emission reduction with constant emission factors overestimates the emission reduction for most measures in San Diego, while it underestimates the emission reduction for most measures in Denver and International Falls; (2) The same retrofit measure may have different effects in CO2 emission reduction depending on the climates. For instance, improving lighting efficiency and improving equipment efficiency have less impacts in emission reduction in cold climates than hot climates; and (3) The most energy efficient measure may not be the most emission efficient measure. For example, in Great Falls, the most energy efficient measure is improving equipment efficiency, but the most emission efficient measure is improving heating efficiency.

Lou, Yingli↗
DOE OSTI2021

Long-term carbon emission reduction potential of building retrofits with dynamically changing electricity emission factors

Buildings account for approximately 36% of the United States' total carbon emissions and building retrofits have great potential to reduce carbon emissions. Current research adopts a constant electricity emission factor although it changes over time due to the increase of renewable energy generation. Here, to accurately predict emission reduction potential of building retrofits, this study develops a novel method by using dynamically changing electricity emission factors. Using medium office buildings as an example, we predicted emission reduction of eight building retrofit measures from 2020 to 2050 in five locations in the U.S. with distinct climates and renewable adoption rates. To evaluate emission reduction potential sensitivity to the compositions of electricity generation, five scenarios for renewable energy adoptions are investigated. The results reveal several new phenomena on emission reduction potential of building retrofits for medium offices in the U.S.: (1) it decreases from 2026 to 2050; (2) it has the same trend with coal usage; and (3) it reaches the maximum under the high renewable cost scenario. Based on the results, it is recommended that building retrofits should focus on 1) improving lighting and equipment efficiency; 2) locations with higher coal usage rate, and 3) buildings under the high renewable cost scenario. The new method can also be used for predicting emission reduction potential of the building sector in the U.S. by applying to other building types and regions.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Widespread Wildfires Over the Western United States in 2020 Linked to Emissions Reductions During COVID-19

Widespread wildfires struck western United States in 2020, directly damaging properties and threatening human lives. Meanwhile, the COVID-19 pandemic rapidly spread across the globe in 2020, which disrupted human activities and resulted in substantial reductions in anthropogenic emissions. Here, we investigate the effects of the emissions reductions of aerosols, precursors, and greenhouse gases during the pandemic on wildfire weather conditions in 2020 over western United States by using an earth system model together with observational data. We show that the COVID-19 emissions reductions in model experiments increased surface air temperature and decreased precipitation and relative humidity due to a weakened moisture transport, which explains 10-40% of the observed increase in the risk of wildfires over western United States in 2020. In conclusion, this study suggests that COVID-19-related abrupt emissions reductions have an unexpected influence on wildfires, highlighting a different but important role of human activities in affecting wildfire risks.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2016

Climate and Health Impacts of US Emissions Reductions Consistent with 2 C

An emissions trajectory for the US consistent with 2 C warming would require marked societal changes, making it crucial to understand the associated benefits. Previous studies have examined technological potentials and implementation costs and public health benefits have been quantified for less-aggressive potential emissions-reduction policies, but researchers have not yet fully explored the multiple benefits of reductions consistent with 2 C. We examine the impacts of such highly ambitious scenarios for clean energy and vehicles. US transportation emissions reductions avoid approx.0.03 C global warming in 2030 (0.15 C in 2100), whereas energy emissions reductions avoid approx.0.05-0.07 C 2030 warming (approx.0.25 C in 2100). Nationally, however, clean energy policies produce climate disbenefits including warmer summers (although these would be eliminated by the remote effects of similar policies if they were undertaken elsewhere). The policies also greatly reduce damaging ambient particulate matter and ozone. By 2030, clean energy policies could prevent approx.175,000 premature deaths, with approx.22,000 (11,000-96,000; 95% confidence) fewer annually thereafter, whereas clean transportation could prevent approx.120,000 premature deaths and approx.14,000 (9,000-52,000) annually thereafter. Near-term national benefits are valued at approx.US$250 billion (140 billion to 1,050billion) per year, which is likely to exceed implementation costs. Including longer-term, worldwide climate impacts, benefits roughly quintuple, becoming approx.5-10 times larger than estimated implementation costs. Achieving the benefits, however, would require both larger and broader emissions reductions than those in current legislation or regulations.

policies↗
DOE OSTI2022

Abrupt emissions reductions during COVID-19 contributed to record summer rainfall in China

Record rainfall and severe flooding struck eastern China in the summer of 2020. The extreme summer rainfall occurred during the COVID-19 pandemic, which started in China in early 2020 and spread rapidly across the globe. By disrupting human activities, substantial reductions in anthropogenic emissions of greenhouse gases and aerosols might have affected regional precipitation in many ways. Here, we investigate such connections and show that the abrupt emissions reductions during the pandemic strengthened the summer atmospheric convection over eastern China, resulting in a positive sea level pressure anomaly over northwestern Pacific Ocean. The latter enhanced moisture convergence to eastern China and further intensified rainfall in that region. Modeling experiments show that the reduction in aerosols had a stronger impact on precipitation than the decrease of greenhouse gases did. We conclude that through abrupt emissions reductions, the COVID-19 pandemic contributed importantly to the 2020 extreme summer rainfall in eastern China.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Realistic Estimation of CO2 Emission Reductions Due to Building Retrofit

Constant CO2 emission factors of electricity are often used to study the emissions of buildings. However, in the era of increased renewable energy for power generation, emission factors of electricity are dynamically changing. This study is to investigate the impact of dynamic CO2 emission factors, which are more realistic than constant ones, on the emission reductions due to building retrofits. The results reveal that if dynamic CO2 emission factors are used for U.S. medium office buildings, improving the efficiency of lighting or electric equipment will lead to more emission reductions in locations with high wind power penetration (e.g., 12% more reductions in Rochester) and fewer reductions in locations with high solar power penetration (e.g., 8% fewer reductions in San Diego). As for improving envelope insulation, dynamic CO2 emission factors have more impact on the emission reductions in hot climates than in cold climates.

Lou, Yingli↗
DOE OSTI2023

Framework for Greenhouse Gas Emissions Reduction Planning: Industrial Portfolios

The Framework for Greenhouse Gas Emissions Reduction Planning: Industrial Portfolios articulates a process to help industrial organizations develop a specific, actionable plan to achieve Scope 1 and Scope 2 greenhouse gas (GHG) emissions reduction – an Emissions Reduction Plan (ERP). An ERP covers an entire portfolio of facilities, yet contains enough detail to be practically useful at the facility level.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Framework for Greenhouse Gas Emissions Reduction Planning: Building Portfolios

The goal of this framework for greenhouse gas (GHG) emissions reduction planning (ERP) is to provide guidance to organizations seeking to reduce GHG emissions for their building portfolios and vehicle fleets. The process described in this framework helps organizations develop an actionable plan that prioritizes emissions reduction measures, identifies solutions, and lays out a phased pathway to achieve deep emissions reductions. The plan aims to result in the achievement of Scope 1 and 2 GHG emissions reduction targets, in alignment with goals set within the U.S. Department of Energy’s (DOE’s) Better Climate Challenge, as well as longer term emissions reduction goals.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

Framework for Greenhouse Gas Emissions Reduction Planning: Building Portfolios

The goal of this Framework for greenhouse gas (GHG) emissions reduction planning (ERP) is to provide guidance to organizations seeking to reduce GHG emissions for their building portfolios and vehicle fleets. The process described in this framework helps organizations develop an actionable plan that prioritizes emissions reduction measures, identifies solutions, and lays out a phased pathway to achieve deep emissions reductions The plan aims to result in the achievement of Scope 1 and 2 GHG emissions reduction targets, in alignment with goals set within the U.S. Department of Energy’s (DOE’s) Better Climate Challenge, as well as longer term emissions reduction goals.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2021

Novel technologies for emission reduction complement conservation agriculture to achieve negative emissions from row-crop production

Plants remove carbon dioxide from the atmosphere through photosynthesis. Because agriculture’s productivity is based on this process, a combination of technologies to reduce emissions and enhance soil carbon storage can allow this sector to achieve net negative emissions while maintaining high productivity. Unfortunately, current row-crop agricultural practice generates about 5% of greenhouse gas emissions in the United States and European Union. Here, to reduce these emissions, significant effort has been focused on changing farm management practices to maximize soil carbon. In contrast, the potential to reduce emissions has largely been neglected. Through a combination of innovations in digital agriculture, crop and microbial genetics, and electrification, we estimate that a 71% (1,744 kg CO 2 e/ha) reduction in greenhouse gas emissions from row crop agriculture is possible within the next 15 y. Importantly, emission reduction can lower the barrier to broad adoption by proceeding through multiple stages with meaningful improvements that gradually facilitate the transition to net negative practices. Emerging voluntary and regulatory ecosystems services markets will incentivize progress along this transition pathway and guide public and private investments toward technology development. In the difficult quest for net negative emissions, all tools, including emission reduction and soil carbon storage, must be developed to allow agriculture to maintain its critical societal function of provisioning society while, at the same time, generating environmental benefits.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Decarbonizing the grid: Utilizing demand-side flexibility for carbon emission reduction through locational marginal emissions in distribution networks

Decarbonization of the electric grid has become an important world-wide priority and is actively happening in many ways by introducing innovations and new technologies from the generation sectors to the demand sectors. In particular, one promising pathway toward such net-zero carbon emissions is to utilize the demand-side flexibility with the increasing number of flexible loads in distribution networks. In this paper, we explore a load shifting strategy with the emerging concept of location marginal emissions (LMEs) to reduce carbon emissions. LMEs measure the impact of carbon emissions including the locational aspect in more granular way and thus provide a novel mechanism for the system operator and load aggregators to design the LME-based load shifting strategy, which can efficiently guide consumers and thus adjust their consumption behaviors. Simulation case studies on the IEEE test networks are performed to validate the capability of the proposed load shifting method to reduce carbon emissions. We also compare this with other relevant strategies to discuss multiple scenarios and corresponding results. Finally, while each provides a different level of flexibility, all the explored strategies tested have led to solutions that have lower carbon emissions, indicating the great potential of demand-side flexibility in reducing carbon emissions for future distribution networks.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2025

The DREAM approach to demand-side emissions reductions in Indonesia, 2020–2060

Indonesia’s current energy system modeling is heavily focused on the supply side, but emissions reductions in the demand sector have a significant impact on advancing Indonesia’s ambitious emissions reductions goals. To address the gap, we develop a new modeling tool DREAM Indonesia based on a bottom-up, technology-rich demand side framework and formulate projections of demand-side emissions reductions in Indonesia in 2020–2060. We find that demand-side energy efficiency and electrification can halve the growth rate of final energy demand to 1.4% annually over 2020–2060 and reverse the growing trend of emissions. The feasibility of full electrification by 2060, coupled with rapid adoption of existing technologies, positions the building sector as a model for achievable decarbonization and a cornerstone of Indonesia’s emissions reductions ambitions. In the industrial sector, extensive emissions reductions of 87% by 2060 (compared to business-as-usual) are achievable through energy efficiency improvements, alongside enhanced material efficiency measures including optimized material usage, low-carbon substitutions, innovative technologies, and increased circularity. In the transportation sector, balancing final energy demand by incorporating energy efficiency improvements across all transport modes, along with electrification particularly in road transportation, could decrease the emissions by up to 82% in 2060 compared to business-as-usual. This study provides insights and modeling approaches for rapidly growing Asian economies as well as other developing countries facing combined development and decarbonization challenges.

DREAM Indonesia↗
DOE OSTI2023

Fast Response of East Asian Precipitation in June 2020 to Local and Remote Aerosol Emission Reductions during COVID-19

Here, in this study, the fast response of East Asian summer precipitation to COVID-19–induced aerosol emission reductions is examined using the Community Earth System Model, version 2.2 (CESM2.2). The emission reductions decreased aerosol optical depth and cloud cover over northern China in June 2020. The troposphere became warmer, strengthening the land–sea thermal contrast and anomalous southerly winds. The subtropical westerly jet accelerated and shifted southward, favoring low-level convergence, upward air motions, and subsequent condensational heating over the Yangtze River basin (YRB). The feedback of condensational heating in return strengthened the convergence and ascent. The western North Pacific subtropical high was intensified, which further enhanced the moisture advection and convergence over the YRB. Both the enhanced moisture convergence and ascent increased precipitation over the YRB during June 2020. Furthermore, local and remote emission reductions show different impacts on convection and moisture transport over the YRB. The emission reductions over China caused stronger convective precipitation (1.15 vs 0.63 mm day −1 ) but weaker larger-scale precipitation (1.17 vs 2.24 mm day −1 ) than the emission reductions outside China. In addition to the emission reductions, the sea surface temperature (SST) anomalies in 2020 also play an important role in increasing precipitation over the YRB, contributing about 42.8%. The relative contribution of SST anomalies also increases under the COVID-19–induced emission scenario.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Adoption of Plug-in Electric Vehicles: Local Fuel Use and Greenhouse Gas Emissions Reductions Across the U.S.

The dependence on gasoline-powered light-duty automobiles has made U.S. households vulnerable to the burden of fuel costs. Tailpipe emissions from these vehicles constitute 58% of greenhouse gas (GHG) emissions in the U.S., which are damaging to the environment (EPA, 2023). The adoption of plug-in electric vehicles (PEVs) has been shown to effectively reduce fuel costs and GHG emissions. However, local effects on these benefits are not well understood by American consumers, potentially limiting adoption and therefore the realization of PEV benefits at scale (MacInnis & Krosnick, 2020; EY Americas, 2023). To fill this research gap, this study estimates the fuel cost savings and GHG emission reductions at the state and ZIP code levels by considering local fuel prices, vehicle class preference, average vehicle model year, fuel efficiencies, and driving intensities. The study's findings reveal that the adoption of PEVs can yield substantial benefits in terms of fuel cost savings and GHG emission reductions nationwide. Specifically, driving a battery electric vehicle (BEV) is estimated to result in annual savings of up to $\$2,200$, while driving a plug-in hybrid electric vehicle (PHEV) can lead to savings up to $\$1,500$, when compared to an internal combustion engine vehicle (ICEV) of equivalent size. Moreover, using population-weighted averages by ZIP code, BEVs and PHEVs show the potential to save 400 and 200 grams of carbon dioxide equivalent per mile, respectively, compared to a representative ICEV of the same class. The magnitude of fuel cost savings and emissions reduction vary by region due to various factors. Generally, regions with high gasoline prices, low electricity prices, preferences for larger vehicles, and high driving intensities tend to see relatively large fuel savings. The emissions reductions are more pronounced in areas with clean grids where consumer preferences lie with large vehicles. This regional variability underscores the importance of considering local contextual factors when assessing the potential benefits of PEV adoption. In more than 99% of U.S. ZIP codes, PEVs result in overall savings in fuel use (and subsequent costs) and GHG emissions. While not a central focus of this analysis, reductions in GHG tailpipe emissions from PEV adoption would also come with reductions in criteria pollutant emissions, contributing to improved local air quality depending on the PEV penetration, population density, and electricity generation infrastructure in the locality.

33 ADVANCED PROPULSION SYSTEMS↗
NASA NTRS2018

Connecting Regional Aerosol Emissions Reductions to Local and Remote Precipitation Responses

The unintended climatic implications of aerosol and precursor emission reductions implemented to protect public health are poorly understood. We investigate the precipitation response to regional changes in aerosol emissions using three coupled chemistry-climate models: NOAA Geophysical Fluid Dynamics Laboratory Coupled Model 3 (GFDL-CM3), NCAR Community Earth System Model (CESM1), and NASA Goddard Institute for Space Studies ModelE2 (GISS-E2). Our approach contrasts a long present-day control simulation from each model (up to 400 years with perpetual year 2000 or 2005 emissions) with 14 individual aerosol emissions perturbation simulations (160-240 years each). We perturb emissions of sulfur dioxide and/or carbonaceous aerosol within six world regions and assess the significance of precipitation responses relative to internal variability determined by the control simulation and across the models. Global and regional precipitation mostly increases when we reduce regional aerosol emissions in the models, with the strongest responses occurring for sulfur dioxide emissions reductions from Europe and the United States. Precipitation responses to aerosol emissions reductions are largest in the tropics and project onto the El Nino Southern Oscillation (ENSO). Regressing precipitation onto an Indo-Pacific zonal sea level pressure gradient index (a proxy for ENSO) indicates that the ENSO component of the precipitation response to regional aerosol removal can be as large as 20% of the total simulated response. Precipitation increases in the Sahel in response to aerosol reductions in remote regions because an anomalous interhemispheric temperature gradient alters the position of the Intertropical Convergence Zone (ITCZ). This mechanism holds across multiple aerosol reduction simulations and models.

Westervelt, Daniel M.↗
NASA NTRS2012

A HTAP Multi-Model Assessment of the Influence of Regional Anthropogenic Emission Reductions on Aerosol Direct Radiative Forcing and the Role of Intercontinental Transport

In this study, we assess changes of aerosol optical depth (AOD) and direct radiative forcing (DRF) in response to the reduction of anthropogenic emissions in four major pollution regions in the northern hemisphere by using results from 10 global chemical transport models in the framework of the Hemispheric Transport of Air Pollution (HTAP). The multi-model results show that on average, a 20% reduction of anthropogenic emissions in North America, Europe, East Asia and South Asia lowers the global mean AOD and DRF by about 9%, 4%, and 10% for sulfate, organic matter, and black carbon aerosol, respectively. The impacts of the regional emission reductions on AOD and DRF extend well beyond the source regions because of intercontinental transport. On an annual basis, intercontinental transport accounts for 10-30% of the overall AOD and DRF in a receptor region, with domestic emissions accounting for the remainder, depending on regions and species. While South Asia is most influenced by import of sulfate aerosol from Europe, North America is most influenced by import of black carbon from East Asia. Results show a large spread among models, highlighting the need to improve aerosol processes in models and evaluate and constrain models with observations.

Yu, Hongbin↗
NASA NTRS2018

Quantified, Localized Health Benefits of Accelerated Carbon Dioxide Emissions Reductions

Societal risks increase as Earth warms, and increase further for emissions trajectories accepting relatively high levels of near-term emissions while assuming future negative emissions will compensate, even if they lead to identical warming as trajectories with reduced near-term emissions. Accelerating carbon dioxide (CO2) emissions reductions, including as a substitute for negative emissions, hence reduces long-term risks but requires dramatic near-term societal transformations. A major barrier to emissions reductions is the difficulty of reconciling immediate, localized costs with global, long-term benefits. However, 2 C trajectories not relying on negative emissions or 1.5 C trajectories require elimination of most fossil-fuel-related emissions. This generally reduces co-emissions that cause ambient air pollution, resulting in near-term, localized health benefits. We therefore examine the human health benefits of increasing 21st-century CO2 reductions by 180 GtC, an amount that would shift a 'standard' 2 C scenario to 1.5 C or could achieve 2 C without negative emissions. The decreased air pollution leads to 153 +/- 43 million fewer premature deaths worldwide, with approx.40% occurring during the next 40 years, and minimal climate disbenefits. More than a million premature deaths would be prevented in many metropolitan areas in Asia and Africa, and greater than 200,000 in individual urban areas on every inhabited continent except Australia.

Atmospheric science↗
NASA NTRS1977

Summary of emissions reduction technology programs

The NASA emissions reduction contract programs for EPA aircraft engine classes P2 (turboshaft engines), T1 (jet engines with thrust under 8000 lb), T4 (JT8D) engines), and T2 (jet engines with thrust over 8000 lb) are discussed. The most important aspects of these programs, the commonality of approaches used, the test results, and assessments regarding applications of the derived technology are summarized.

Niedzwiecki, R. W.↗