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At least 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Policy implications of net-zero emissions: A multi-model analysis of United States emissions and energy system impacts

Many countries, subnational jurisdictions, and companies are setting net-zero emissions goals; however, questions remain about strategies to reach these targets, policy measures, technology gaps, and economic impacts. Here, we investigate the potential policy implications of reaching economy-wide net-zero CO 2 emissions across the United States by 2050 using results from a multi-model comparison with 14 energy-economic models. Model results suggest that achieving net-zero CO 2 targets depends on policies that accelerate deployment of zero- and low-emitting technologies that have seen rapid cost reductions in recent years (including wind, solar, battery storage, and electric vehicles) as well as relatively nascent options (including carbon capture and storage, advanced biofuels, low-carbon hydrogen, advanced nuclear, and long-duration energy storage). While net-zero policies are likely to lower fossil fuel consumption, including considerable coal and petroleum reductions, achieving net-zero emissions does not necessarily mean phasing out all fossil fuels. Model results indicate that the Inflation Reduction Act’s energy and climate provisions amplify near-term decarbonization but that net-zero policies have larger impacts on long-run outcomes. Stringent climate policy can have large fiscal impacts on tax revenue and government spending—revenues from carbon pricing and subsidies for carbon removal range from 0.1 % to 3.7 % of GDP in 2050 across models. Each dollar per metric ton carbon price leads to a 0.06 % to 0.31 % reduction in economy-wide CO 2 emissions relative to a reference scenario with current policies. Spending on energy across the economy decreases relative to today for many models under reference and net-zero policies, especially as a share of GDP, due primarily to end-use electrification and energy efficiency.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Regional Analysis of Building Distributed Energy Costs and CO2 Abatement: A U.S. - China Comparison

The following paper conducts a regional analysis of the U.S. and Chinese buildings? potential for adopting Distributed Energy Resources (DER). The expected economics of DER in 2020-2025 is modeled for a commercial and a multi-family residential building in different climate zones. The optimal building energy economic performance is calculated using the Distributed Energy Resources Customer Adoption Model (DER CAM) which minimizes building energy costs for a typical reference year of operation. Several DER such as combined heat and power (CHP) units, photovoltaics, and battery storage are considered. The results indicate DER have economic and environmental competitiveness potential, especially for commercial buildings in hot and cold climates of both countries. In the U.S., the average expected energy cost savings in commercial buildings from DER CAM?s suggested investments is 17percent, while in Chinese buildings is 12percent. The electricity tariffs structure and prices along with the cost of natural gas, represent important factors in determining adoption of DER, more so than climate. High energy pricing spark spreads lead to increased economic attractiveness of DER. The average emissions reduction in commercial buildings is 19percent in the U.S. as a result of significant investments in PV, whereas in China, it is 20percent and driven by investments in CHP. Keywords: Building Modeling and Simulation, Distributed Energy Resources (DER), Energy Efficiency, Combined Heat and Power (CHP), CO2 emissions 1. Introduction The transition from a centralized and fossil-based energy paradigm towards the decentralization of energy supply and distribution has been a major subject of research over the past two decades. Various concerns have brought the traditional model into question; namely its environmental footprint, its structural inflexibility and inefficiency, and more recently, its inability to maintain acceptable reliability of supply. Under such a troubled setting, distributed energy resources (DER) comprising of small, modular, electrical renewable or fossil-based electricity generation units placed at or near the point of energy consumption, has gained much attention as a viable alternative or addition to the current energy system. In 2010, China consumed about 30percent of its primary energy in the buildings sector, leading the country to pay great attention to DER development and its applications in buildings. During the 11th Five Year Plan (FYP), China has implemented 371 renewable energy building demonstration projects, and 210 photovoltaics (PV) building integration projects. At the end of the 12th FYP, China is targeting renewable energy to provide 10percent of total building energy, and to save 30 metric tons of CO2 equivalents (mtce) of energy with building integrated renewables. China is also planning to implement one thousand natural gas-based distributed cogeneration demonstration projects with energy utilization rates over 70percent in the 12th FYP. All these policy targets require significant DER systems development for building applications. China?s fast urbanization makes building energy efficiency a crucial economic issue; however, only limited studies have been done that examine how to design and select suitable building energy technologies in its different regions. In the U.S., buildings consumed 40percent of the total primary energy in 2010 [1] and it is estimated that about 14 billion m2 of floor space of the existing building stock will be remodeled over the next 30 years. Most building?s renovation work has been on building envelope, lighting and HVAC systems. Although interest has emerged, less attention is being paid to DER for buildings. This context has created opportunities for research, development and progressive deployment of DER, due to its potential to combine the production of power and heat (CHP) near the point of consumption and delivering multiple benefits to customers, such as cost

25 ENERGY STORAGE↗
DOE OSTI2022

Dynamic optimization with flexible heat integration of a solar parabolic trough collector plant with thermal energy storage used for industrial process heat

There is an increasing need to reduce fossil fuel consumption used for industrial process heat to slow the effects of climate change. Using solar thermal heat is a viable way to replace fossil fuel use, but solar industrial process heat plants have limited implementation due to large upfront costs and inefficiencies from the inherent variability from solar energy. Having more flexible and optimized control over these plants can enable them to be more efficient. Here in this work, a solar industrial process heat plant with thermal energy storage that can flexibly collect and deliver heat to two industrial processes (flexible heat integration) is dynamically modeled with control setpoints found by a dynamic optimization method. The optimized case can increase the solar efficiency of the plant by 7.5% on average relative to a base case. The results show that it is best to collect heat at lower temperatures for all but ideal solar conditions, only medium to high quality heat should be stored in large quantities, and exchanging heat with a lower temperature heat sink is generally more efficient. The optimized case is able to reduce the levelized cost of heat of the plant to $31.83/MWh th compared to a base case value of $34.10/MWh th . The optimized case can reduce emissions by 22.2% compared to a plant which uses only natural gas. This work shows that dynamic optimization with flexible heat integration can be a cost-effective way to increase efficiency so that more of these types of plants can be implemented.

14 SOLAR ENERGY↗
DOE OSTI2016

Emissions reduction scenarios in the Argentinean Energy Sector

Here in this paper the LEAP, TIAM-ECN, and GCAM models were applied to evaluate the impact of a variety of climate change control policies (including carbon pricing and emission constraints relative to a base year) on primary energy consumption, final energy consumption, electricity sector development, and CO 2 emission savings of the energy sector in Argentina over the 2010-2050 period. The LEAP model results indicate that if Argentina fully implements the most feasible mitigation measures currently under consideration by official bodies and key academic institutions on energy supply and demand, such as the ProBiomass program, a cumulative incremental economic cost of 22.8 billion US$(2005) to 2050 is expected, resulting in a 16% reduction in GHG emissions compared to a business-as-usual scenario. These measures also bring economic co-benefits, such as a reduction of energy imports improving the balance of trade. A Low CO 2 price scenario in LEAP results in the replacement of coal by nuclear and wind energy in electricity expansion. A High CO 2 price leverages additional investments in hydropower. An emission cap scenario (2050 emissions 20% lower than 2010 emissions) is feasible by including such measures as CCS and Bio CCS, but at a significant cost. By way of cross-model comparison with the TIAM-ECN and GCAM global integrated assessment models, significant variation in projected emissions reductions in the carbon price scenarios was observed, which illustrates the inherent uncertainties associated with such long-term projections. These models predict approximately 37% and 94% reductions under the High CO 2 price scenario, respectively. By comparison, the LEAP model, using an approach based on the assessment of a limited set of mitigation options, predicts a 11.3% reduction under the ‘high’ carbon tax. The main reasons for this difference are differences in assumptions about technology cost and availability, CO 2 storage capacity, and the ability to import bioenergy. In terms of technology pathways, the models agree that fossil fuels, in particular natural gas, will remain an important part of the electricity mix in the core baseline scenario. Finally, according to the models there is agreement that the introduction of a carbon price will lead to a decline in absolute and relative shares of aggregate fossil fuel generation. However, predictions vary as to the extent to which coal, nuclear and renewable energy play a role.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2016

A multi-model study of energy supply investments in Latin America under climate control policy

In this article we investigate energy supply investment requirements in Latin America until 2050 through a multi-model approach as jointly applied in the CLIMACAP-LAMP research project. We compare a business-as-usual scenario needed to satisfy anticipated future energy demand with a set of scenarios that aim to significantly reduce CO 2 emissions in the region. We find that more than a doubling of annual investments, in absolute terms, occurs in the business-as-usual scenario between 2010 and 2050, while investments may treble over the same time horizon when climate policies are introduced. However, investment costs as a share of GDP decline over time in the business-as-usual scenario, as well as the climate policy scenarios, due to the fast economic growth in that region. Business-as-usual cumulative investments of 1.4 trillion US$ are anticipated between 2010 and 2050 in energy supply, and increase when additional climate policies are introduced: under a carbon tax of 50 $/tCO 2 e in 2020 increasing with a rate of 4% per year, an additional 0.6 trillion US$ (+45%) investment is needed. Climate control measures lead to increased investment in low-carbon electricity technologies, primarily wind, solar, and CCS applied to fossil fuels and biomass. Our analysis suggests that compared to the business-as-usual case an average additional 21 billion US$ per year of electricity supply investments is required in Latin America until 2050 under a climate policy aiming at 2°C climate stabilization. Conversely, there is a disinvestment in fossil fuels. For oil production, a growth from 58 billion US$ to 130 billion US$ annual investment by 2050 is anticipated in a business-as-usual scenario: ambitious climate policy reduces this to 28 billion US$. Finally, mobilizing necessary additional investment capital, in particular for low-carbon technologies, will be a challenge, and suitable frameworks and enabling environments for a scale-up in public and private investment will be critical to help reach required levels. The economic case for such a transition still remains to be articulated.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Comparing projections of industrial energy demand and greenhouse gas emissions in long-term energy models

The industry sector consumes more energy and emits more greenhouse gas (GHG) emissions than any other end-use sector. Integrated assessment models (IAMs) and energy system models have been widely used to evaluate climate policy at a global level, and include a representation of industrial energy use. In this study, the projected industrial energy use and accompanying GHG emissions, as well as the model structure of multiple long-term energy models are compared. The models show varying degrees to which energy consumption is decoupled from GDP growth in the future. In all models, the sector remains mostly (>50%) reliant on fossil energy through 2100 in a reference scenario (i.e., absent emissions mitigation policies), though there is significant divergence in the projected ability to switch to alternative fuels to mitigate GHG emissions. Among the set analyzed here, the more technologically detailed models tend to have less capacity for switching from fossil fuels to electricity. This highlights the importance of understanding of economy-wide mitigation responses and costs as an area for future improvement. Analyzing industry subsector material and energy use details can improve the ability to interpret results, and provide insight in feasibility of how emissions reduction can be achieved.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2013

Implications of uncertainty on regional CO2 mitigation policies for the U.S. onroad sector based on a high-resolution emissions estimate

In this study we present onroad fossil fuel CO2 emissions estimated by the Vulcan Project, an effort quantifying fossil fuel CO2 emissions for the U.S. in high spatial and temporal resolution. This high-resolution data, aggregated at the state-level and classified in broad road and vehicle type categories, is compared to a commonly used national-average approach. We find that the use of national averages incurs state-level biases for road groupings that are almost twice as large as for vehicle groupings. The uncertainty for all groups exceeds the bias, and both quantities are positively correlated with total state emissions. States with the largest emissions totals are typically similar to one another in terms of emissions fraction distribution across road and vehicle groups, while smaller-emitting states have a wider range of variation in all groups. Errors in reduction estimates as large as ±60% corresponding to ±0.2 MtC are found for a national-average emissions mitigation strategy focused on a 10% emissions reduction from a single vehicle class, such as passenger gas vehicles or heavy diesel trucks. Recommendations are made for reducing CO2 emissions uncertainty by addressing its main drivers: VMT and fuel efficiency uncertainty.

Mendoza, D↗
DOE OSTI2013

A Dynamic Simulation of the Indirect Land Use Implications of Recent Biofuel Production and Use in the United States.

The global indirect land use change (ILUC) implications of biofuel use in the United States of America (USA) from 2001 to 2010 are evaluated with a dynamic general equilibrium model. The effects of biofuels production on agricultural land area vary by year; from a net expansion of 0.17 ha per 1000 gallons produced (2002) to a net contraction of -0.13 ha per 1000 gallons (2018) in Case 1 of our simulation. In accordance with the general narrative about the implications of biofuel policy, agricultural land area increased in many regions of the world. However, oil-export dependent economies experienced agricultural land contraction because of reductions in their revenues. Reducing crude oil imports is a major goal of biofuel policy, but the land use change implications have received little attention in the literature. Simulations evaluating the effects of doubling supply elasticities for land and fossil resources show that these parameters can significantly influence the land use change estimates. Therefore, research that provides empirically-based and spatially-detailed agricultural land-supply curves and capability to project future fossil energy prices is critical for improving estimates of the effects of biofuel policy on land use.

Oladosu, Gbadebo A.↗
DOE OSTI2018

Soil carbon inventory to quantify the impact of land use change to mitigate greenhouse gas emissions and ecosystem services

We report that currently the land use and land use change (LULUC) emits 1.3 ± 0.5 Pg carbon (C) year -1 , equivalent to 8% of the global annual emissions. The objectives of this study were to quantify (1) the impact of LULUC on greenhouse gas (GHG) emissions in a subtropical region and (2) the role of conservation agriculture to mitigate GHG emissions promoting ecosystem services. We developed a detailed IPCC Tier 2 GHG inventory for the Campos Gerais region of southern Brazil that has large cropland area under long-term conservation agriculture with high crop yields. The inventory accounted for historical and current emissions from fossil fuel combustion, LULUC and other minor sources. We used Century model to simulate the adoption of conservation best management practices, to all croplands in the region from 2017 to 2117. Our results showed historical (1930 – 2017) GHG emissions of 412 Tg C, in which LULUC contributes 91% (376±130 Tg C), the uncertainties ranged between 13 and 36%. Between 1930 and 1985 LULUC was a major source of GHG emission, however from 1985 to 2015 fossil fuel combustion became the primary source of GHG emission. Forestry sequestered 52 ± 24 Tg C in 0.6 Mha in a period of 47 years (1.8 Tg C Mha -1 year -1 ) and no-till sequestered 30.4 ± 24 Tg C in 2 Mha in a period of 32 years (0.5 Tg C Mha -1 year -1 ) being the principal GHG mitigating activities in the study area. Lastly, the model predictions showed that best management practices have the potential to mitigate 13 years of regional emissions (330 Tg C in 100 years) or 105 years of agriculture, forestry and livestock emissions (40 Tg C in 100 years) making the agriculture sector a net carbon (C) sink and promoting ecosystem services.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Comparison of well-to-wheels energy use and emissions of a hydrogen fuel cell electric vehicle relative to a conventional gasoline-powered internal combustion engine vehicle

The operation of hydrogen fuel cell electric vehicles (HFCEVs) is more efficient than that of gasoline conventional internal combustion engine vehicles (ICEVs), and produces zero tailpipe pollutant emissions. However, the production, transportation, and refueling of hydrogen are more energy- and emissions-intensive compared to gasoline. In this research, a well-to-wheels (WTW) energy use and emissions analysis was conducted to compare a HFCEV (Toyota Mirai) with a gasoline conventional ICEV (Mazda 3). Two sets of specific fuel consumption data were used for each vehicle: (1) fuel consumption derived from the U.S. Environmental Protection Agency's (EPA's) window-sticker fuel economy figure, and (2) weight-averaged fuel consumption based on physical vehicle testing with a chassis dynamometer on EPA's five standard driving cycles. The WTW results show that a HFCEV, even fueled by hydrogen from a fossil-based production pathway (via steam methane reforming of natural gas), uses 5%–33% less WTW fossil energy and has 15%–45% lower WTW greenhouse gas emissions compared to a gasoline conventional ICEV. The WTW results are sensitive to the source of electricity used for hydrogen compression or liquefaction.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2021

Life Cycle Analysis of Renewable Natural Gas and Lactic Acid Production from Waste Feedstocks

Producing fuels and chemicals from waste is considered economically favorable, due to low feedstock cost, and environmentally favorable, due to avoided emissions from conventional waste management practices. In this study, we evaluate the life cycle greenhouse gas (GHG) emission reduction benefits of renewable natural gas (RNG) and lactic acid (LA) production from four types of wet waste feedstocks (wastewater sludge, food waste, swine manure, and fats, oil, and grease [FOG]) via anaerobic digestion (AD) and LA fermentation, respectively. RNG can be used as an alternative to fossil natural gas, while LA from waste feedstocks can displace conventional LA production pathways (mainly from corn via fermentation). Providing comprehensive life cycle GHG emissions of the combinations of waste feedstocks and products through different routes helps identify the GHG hotspots and show where emissions savings come from. The results show that the carbon intensities (CIs) of waste-derived RNG and LA are much lower than those of their counterparts. We estimated the life cycle GHG emissions for RNG to be between -146 and 27 g carbon dioxide equivalent (CO2e)/MJ, much lower than the CI of fossil fuels. Waste-derived LA pathways also show substantially lower CIs, ranging from -4.2 to -1.4 kgCO2e/kg LA, compared to the CIs of LA from corn and corn stover (1.2 and 0.3 kgCO2e/kg LA, respectively). We will also discuss that the low CIs of waste-derived products can come from low yields leading to high emission credits. Thus, life cycle analysis results presented per weight of treated waste can be used to support decisions about which waste feedstocks and products are to be used for sustainable waste valorization. In addition, we found that monetary emission reduction credits can play an important role in driving waste valorization.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2022

Life cycle analysis of gasification and Fischer-Tropsch conversion of municipal solid waste for transportation fuel production

Non-recyclable municipal solid waste (MSW) can be used as feedstock for liquid fuel production via gasification followed by Fischer-Tropsch (FT) processes. Given the heterogeneity of MSW material composition and variation in material properties, its convertibility to liquid hydrocarbon fuels could vary widely, affecting the sustainability of utilizing non-recyclable MSW for fuel production. This study evaluates the life cycle greenhouse gas (GHG) emissions (carbon intensities [CIs]) of FT fuels from non-recyclable MSW. Key issues that could greatly affect the CIs were examined, including fossil carbon content of the MSW, emission implications of diverting non-recyclable MSW from landfills to fuel production, and conversion efficiency. Results show that the CIs of fuels produced from various waste streams range 80–105 gCO2e/MJ, which may exceed the CI of petroleum fuels. Higher fossil carbon content in the MSW feedstock tends to incur higher GHG emissions as biogenic carbon emissions are considered carbon neutral. Meanwhile, diverting different fractions of non-recyclable MSW, such as food waste and low-quality paper, from landfills may result in GHG emissions that may include the potential avoidance of methane emissions and potential sequestration of biogenic carbon that is foregone. To reduce GHG emissions, a carbon capture and sequestration option in the fuel production stage is considered, which could reduce the CI by 53–64 gCO2e/MJ. Carbon fates of different non-recyclable MSW in landfills are further evaluated to determine how they vary and impact the CIs of MSW-derived fuels.

02 PETROLEUM↗
DOE OSTI2023

Life-cycle analysis of recycling of post-use plastic to plastic via pyrolysis

Advanced recycling enables the application of post-use plastics (PUP) to produce valuable industrial chemicals and develop markets for recycled feedstocks. Pyrolysis is one of the most common advanced recycling technologies undergoing industrial-scale implementation for converting PUP. This paper presents a life cycle analysis (LCA) to assess greenhouse gas (GHG) emissions, fossil energy, water consumption, and solid waste impacts of converting PUP into new plastics such as high-density and low-density polyethylene (HDPE and LDPE, respectively). Data was collected from eight plastic pyrolysis companies. This study addresses the impacts of pyrolysis plant size and maturity; two substitution rate (SR) cases of pyrolysis oil with fossil-derived feedstocks in steam crackers (5% and a 20% of pyrolysis oil SR); and potentially avoided emissions from traditional end-of-life (EOL) management. Because the conventional feedstock slate of steam crackers in the Unites States is comprised of 94% gases (a mix of ethane, propane, and butane) and 6% naphtha, the 5% SR case looked at polyethylene (PE) derived from 5% pyrolysis oil, 1% naphtha, and 94% gases; while the 20% SR looked at PE derived from 20% pyrolysis oil and 80% gases. Moreover, the results are presented from two perspectives: 1) steam crackers' and 2) plastic recyclers'. In the recyclers' perspective, the results for the 5% SR showed for each kg of PUP used there was a 23% and 18% decrease in GHG emissions for HDPE and LDPE respectively, while the 20% SR showed a 4% and 3% reduction in GHG emissions for HDPE and LDPE respectively compared to virgin plastic. The 20% SR has lower GHG emissions reductions because there is an added step of hydrotreating the pyrolysis oil to remove chlorine concentrations that is not included in the 5% SR scenario. Furthermore, the 5% SR removes most of the naphtha, a more carbon intense feedstock, and replaces it with PUP-based pyrolysis oil, a less carbon intense feedstock. GHG emissions for PUP pyrolysis could be further reduced by 50% and 131% in the United States and European Union respectively if the GHG emissions of current PUP incineration practices were considered as emission reductions credits.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2024

Comparative life cycle analysis on ethylene production from electrocatalytic reduction of carbon dioxide

Ethylene is one of the largest greenhouse gas emitters and the most diversly used commodity chemicals globally. Electrocatalytic reduction of CO 2 to ethylene received great attention from the research society to decarbonize the ethylene production. Here, in this study, a life-cycle analysis is conducted using the Greenhouse Gases, Regulated Emissions, and Energy use in Technologies (GREET) model on the three electrocatalytic CO 2 -reduction pathways (or “e-ethylene” pathways): i) cascade conversion via carbon monoxide intermediate; ii) single-step conversion in membrane electrode assembly (MEA); and iii) single-step conversion in alkaline flow cell. The results showed that the electricity consumption is the lowest for the cascade pathway (164 MJ/kg), thus resulting in the lowest cradle-to-gate carbon intensity [18 kgCO 2 e/kg with United States (US) average grid)] among the three pathways followed by the single-step MEA (32 kgCO 2 e/kg) and then by the single-step alkaline (56 kgCO 2 e/kg). However, all three e-ethylene pathways were significantly more carbon-intensive than their fossil-based counterpart (1.1 kgCO 2 e/kg) due to their excessive energy consumption with the current state of technology. With renewable electricity, all three pathways yielded negative carbon intensity: from -3.1 kgCO 2 e/kg to -1.6 kgCO 2 e/kg depending on the source of CO 2 . The threshold carbon intensity of electricity (TCIE), defined as the upper bound of the carbon intensity of electricity to achieve lower carbon intensity for e-ethylene compared to fossil-based ethylene, is calculated for both current and future state of e-ethylene technologies. The cascade pathway had the highest TCIE out of the three e-ethylene pathways for both current (92 gCO 2 e/kWh) and future (124 gCO 2 e/kWh) state of technologies. However, the carbon intensity of average US grid (i.e., 467 and 303 gCO 2 e/kWh for current and future projections) were higher than the TCIEs of the corresponding timeline. Thus, reducing electricity requirement for e-ethylene pathways and bringing low-carbon generation mix in the United States (US) grid faster than the current projection are both essential to decarbonize ethylene and its downstream chemicals/polymers.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2024

Toward sustainable electrochemically mediated separations driven by renewable energy

Environmental pollution, water scarcity, resource shortage, and fossil fuel reliance have all represented threats to a sustainable future. Separation processes play a pivotal role in improving sustainability in fields such as industrial processes, resource recycling, wastewater treatment, and water desalination, among others. Electrochemical systems have gained increased attention as effective separation platforms, not only in performance but also as a potentially energy-efficient approach. However, the reliance on non-renewable energy sources, such as fossil fuels, for electricity generation limits the advancement toward a fully sustainable separation process. Integration of separation processes with eco-friendly renewable energy sources can increase overall sustainability and decrease carbon footprint. Here, in this review, we provide an overview of electrochemical separations and recent efforts to integrate them with renewable energy sources such as heat and solar energy. We discuss electrochemical separations, including electrosorption and electrodialysis, and research to transition these processes to thermoelectrochemical (TEC) and photoelectrochemical (PEC) platforms. Finally, we discuss current challenges and future prospects in direct integration of renewable energy sources with separation processes.

electrochemistry↗
DOE OSTI2018

A study on tensile properties of Alloy 709 at various temperatures

In recent years, there have been several advancements in energy production from both fossil fuels and the alternate “clean” sources such as nuclear fission. These advancements are fueled by the need for more efficient systems that will optimize the use of the depleting fossil fuel reserves and shift the focus to cleaner sources of energy. The efficiency of any power generation cycle is dependent on the ability of the structural material to withstand increased peak operating temperatures. Advanced austenitic stainless steels have been in the focus as structural material for the next generation nuclear power plants, due to their strength, corrosion resistance, weldability and the wide range of temperatures at which the austenite phase is stable. Alloy 709, a recently developed advanced austenitic stainless steel, is being investigated in this paper. Here in this study, tensile tests were conducted on dog-bone samples of Alloy 709 in an in-situ scanning electron microscope (SEM) loading and heating stage, equipped with electron backscatter diffraction (EBSD), at various temperatures. The in-situ experiments indicated that the material primarily accommodated deformation by slip at lower temperatures. Void formation and coalescence at grain boundaries preceded slip at higher temperatures. Although crack initiation at all elevated temperatures was intergranular, the crack propagation through the material and the final fracture was transgranular ductile. Additionally, tensile tests were conducted on larger cylindrical samples at 550, 650 and 750 °C in air. The results of tests conducted in air and in-situ were found to be in agreement, at these temperatures.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Future energy infrastructure, energy platform and energy storage

Today fossil energy dominates energy consumption across the world. There has been an increasing momentum to reduce fossil energy consumption and increase renewable energy utilization to more than 70%. Such high penetrations of distributed renewable resources bring large uncertainty and complexity that cannot be easily handled by the current infrastructure. For the last two decades, telecommunication industry has gone through a similar transition from centralized to distributed systems, and more recently to platform approaches, which become the corner stone of today’s vibrant platform economy. Based on telecommunication history, we believe that a platform-based approach, called the energy platform, is a viable solution for addressing the renewable energy challenges. The energy platform consists of an array of computational algorithms, sensing and control technologies for key industry, energy generators and users to jointly manage and control the complex energy infrastructure. It includes the following key components: (1) the hardware and software to generate, store, control and transmit electricity/data (the energy cloud), (2) the digital platforms and tools for key energy producers, digital, service and communication industry to share the assets, participate in and manage the complex infrastructure, and for customers to participate in energy transactions, (3) the transaction platform for new service and business models. Additionally, the energy platform requires breakthroughs in large scale energy storage and many other areas including efficient power electronics, sensors and controls, new mathematical and computational tools, and deep integration of energy technologies and information sciences to control and stabilize such complex chaotic systems.

25 ENERGY STORAGE↗