Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “CAPITAL”

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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Transforming biorefinery designs with ‘Plug-In Processes of Lignin’ to enable economic waste valorization

Biological lignin valorization has emerged as a major solution for sustainable and cost-effective biorefineries. However, current biorefineries yield lignin with inadequate fractionation for bioconversion, yet substantial changes of these biorefinery designs to focus on lignin could jeopardize carbohydrate efficiency and increase capital costs. We resolve the dilemma by designing ‘plug-in processes of lignin’ with the integration of leading pretreatment technologies. Substantial improvement of lignin bioconversion and synergistic enhancement of carbohydrate processing are achieved by solubilizing lignin via lowering molecular weight and increasing hydrophilic groups, addressing the dilemma of lignin- or carbohydrate-first scenarios. The plug-in processes of lignin could enable minimum polyhydroxyalkanoate selling price at as low as $6.18/kg. The results highlight the potential to achieve commercial production of polyhydroxyalkanoates as a co-product of cellulosic ethanol. Here, we show that the plug-in processes of lignin could transform biorefinery design toward sustainability by promoting carbon efficiency and optimizing the total capital cost.

09 BIOMASS FUELS↗
DOE OSTI2023

Assessing the economic viability of unconventional rare earth element feedstocks

Sourcing rare earth elements (REEs) from unconventional feedstocks has substantial environmental and societal-economic benefits, but its economic viability remains unclear. Here, we propose a framework for assessing the economic viability of unconventional REE feedstocks. Here, we first develop a database of capital and operating expenses for REE recovery and establish consistent process unit costs for common stages in the conventional supply chain. We then use market prices to develop well-defined methods for determining diverse product values. Finally, we report the effects of economies of scale and feedstock purity on capital and operating costs. These tools can reduce the uncertainty in the assessment of the economic viability of producing REE from unconventional feedstocks, determine the value of innovative pathways for REE production from diverse sources, and inform research priorities across a wide range of REE product development stages, contributing to a sustainable REE supply.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2016

DMR (deacetylation and mechanical refining) processing of corn stover achieves high monomeric sugar concentrations (230 g L -1 ) during enzymatic hydrolysis and high ethanol concentrations (>10% v/v) during fermentation without hydrolysate purification or concentration

Distilling and purifying ethanol and other products from second generation lignocellulosic biorefineries adds significant capital and operating costs to biofuel production. The energy usage associated with distillation negatively affects plant gate costs and causes environmental and life-cycle impacts, and the lower titers in fermentation caused by lower sugar concentrations from pretreatment and enzymatic hydrolysis increase energy and water usage and ethanol production costs. In addition, lower ethanol titers increase the volumes required for enzymatic hydrolysis and fermentation vessels increase capital expenditure (CAPEX). Therefore, increasing biofuel titers has been a research focus in renewable biofuel production for several decades. In this work, we achieved approximately 230 g L -1 of monomeric sugars after high solid enzymatic hydrolysis using deacetylation and mechanical refining (DMR) processed corn stover substrates produced at the 100 kg per day scale. The high sugar concentrations and low chemical inhibitor concentrations achieved by the DMR process allowed fermentation to ethanol with titers as high as 86 g L -1 , which translates into approximately 10.9% v/v ethanol. To our knowledge, this is the first time that titers greater than 10% v/v ethanol in fermentations derived from corn stover without any sugar concentration or purification steps have been reported. As a result, the potential cost savings from high sugar and ethanol titers achieved by the DMR process are also reported using TEA analysis.

09 BIOMASS FUELS↗
DOE OSTI2016

Techno-economic analysis for upgrading the biomass-derived ethanol-to-jet blendstocks

Here, this study summarizes the detailed techno-economic analysis of the ethanol-to-jet (ETJ) process based on two different feedstocks (corn grain and corn stover) at the plant scale of 2000 dry metric tons per day. Ethanol biologically derived from biomass is upgraded catalytically to jet blendstocks via alcohol dehydration, olefin oligomerization, and hydrotreating. In both pathways, corn-grain-derived ethanol to jet (corn mill ETJ) and corn-stover-derived ethanol to jet (corn stover ETJ), there are portions of gasoline and diesel produced as coproducts. Two cost bases are used in this study: the minimum jet fuel selling prices (MJSP) for jet-range blendstocks and the minimum fuel selling prices (MFSP) for all the hydrocarbons (gasoline, jet, and diesel) produced using a gallon gasoline equivalent (GGE) basis. The n th -plant MJSPs for the two pathways are estimated to be 4.20 per gal for corn mill and 6.14 per gal for corn stover, while MFSPs are 3.91 per GGE for corn mill and 5.37 per GGE for corn stover. If all of the hydrocarbon products (gasoline, jet, and diesel ranges) can be considered as fuel blendstocks using a GGE basis, the total hydrocarbon yield for fuel blendstock is 49.6 GGE per dry ton biomass for corn stover and 71.0 GGE per dry ton biomass for corn grain. The outcome of this study shows that the renewable jet fuel could be cost competitive with fossil derived jet fuel if further improvements could be made to increase process yields (particularly yields of sugars, sugar to ethanol, and ethanol to hydrocarbons), research and development of sustainable feedstocks, and more effective catalytic reaction kinetics. Pioneer plant analysis, which considers the increased capital investment and the decreased plant performance over the nth-plant analysis, is also performed, showing a potential 31%–178% increase in cost compared to the n th -plant assumptions for the dry mill pathway, but with a much wider range of 69%–471% cost increase over the n th -plant assumptions for the corn stover pathway. While there are large differences between the estimated first of a kind plant cost and the targeted nth-plant case, reduction of costs is possible through improvement of the overall process efficiency, yields, reduction in overall capital, co-product revenues and strategically improve performance by process learnings.

09 BIOMASS FUELS↗
DOE OSTI2011

The Nuclear Alternative: Energy Production within Ulaanbaatar, Mongolia

Over ninety percent of Mongolia's energy load is run through the Central Energy System. This primary grid provides Mongolia's capital, Ulaanbaatar, with the power it uses to function. In the first half of 2010 the Central Energy System managed 1739.45 million kWhs, a 4.6 percent increase from 2009. If this growth rate continues, by 2015 Ulaanbaatar's three power plants will be unable to generate enough heat and electricity to meet the city's needs. Currently, plans have been proposed to rehabilitate the aging coal power plants. However, rising maintenance costs and growing emission levels make the long-term sustainability of this solution uncertain. The following paper analyzes the capital, maintenance, and decommissioning costs associated with the current rehabilitation plans and compares them with a nuclear alternative.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2015

Progress of teaching and learning of nuclear engineering courses at College of Engineering, Universiti Tenaga Nasional (UNITEN)

Developing human capital in nuclear with required nuclear background and professional qualifications is necessary to support the implementation of nuclear power projects in the near future. Sufficient educational and training skills are required to ensure that the human resources needed by the nuclear power industry meets its high standard. The Government of Malaysia has made the decision to include nuclear as one of the electricity generation option for the country, post 2020 in order to cater for the increasing energy demands of the country as well as to reduce CO{sub 2} emission. The commitment by the government has been made clearer with the inclusion of the development of first NPP by 2021 in the Economic Transformation Program (ETP) which was launched by the government in October 2010. The In tandem with the government initiative to promote nuclear energy, Center for Nuclear Energy, College of Engineering, Universiti Tenaga Nasional (UNITEN) is taking the responsibility in developing human capital in the area of nuclear power and technology. In the beginning, the College of Engineering has offered the Introduction to Nuclear Technology course as a technical elective course for all undergraduate engineering students. Gradually, other nuclear technical elective courses are offered such as Nuclear Policy, Security and Safeguards, Introduction to Nuclear Engineering, Radiation Detection and Nuclear Instrumentation, Introduction to Reactor Physics, Radiation Safety and Waste Management, and Nuclear Thermal-hydraulics. In addition, another course Advancement in Nuclear Energy is offered as one of the postgraduate elective courses. To enhance the capability of teaching staffs in nuclear areas at UNITEN, several junior lecturers are sent to pursue their postgraduate studies in the Republic of Korea, United States and the United Kingdom, while the others are participating in short courses and workshops in nuclear that are conducted locally and abroad. This paper describes the progress of teaching and learning in nuclear engineering and technology at UNITEN that include curriculum development, students’ enrolment and performance, and teaching staff’s human resource development.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2015

Reduction of Fermi level pinning and recombination at polycrystalline CdTe surfaces by laser irradiation

Laser processing of polycrystalline CdTe is a promising approach that could potentially increase module manufacturing throughput while reducing capital expenditure costs. For these benefits to be realized, the basic effects of laser irradiation on CdTe must be ascertained. In this study, we utilize surface photovoltage spectroscopy (SPS) to investigate the changes to the electronic properties of the surface of polycrystalline CdTe solar cell stacks induced by continuous-wave laser annealing. The experimental data explained within a model consisting of two space charge regions, one at the CdTe/air interface and one at the CdTe/CdS junction, are used to interpret our SPS results. The frequency dependence and phase spectra of the SPS signal are also discussed. To support the SPS findings, low-temperature spectrally-resolved photoluminescence and time-resolved photoluminescence were also measured. The data show that a modest laser treatment of 250 W/cm{sup 2} with a dwell time of 20 s is sufficient to reduce the effects of Fermi level pinning at the surface due to surface defects.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Comparing the Net Cost of CSP-TES to PV Deployed with Battery Storage

Concentrated solar power with thermal energy storage (CSP-TES) is a unique source of renewable energy in that its energy can be shifted over time and it can provide the electricity system with dependable generation capacity. In this study, we provide a framework to determine if the benefits of CSP-TES (shiftable energy and the ability to provide firm capacity) exceed the benefits of PV and firm capacity sources such as long-duration battery storage or conventional natural gas combustion turbines (CTs). The results of this study using current capital cost estimates indicate that a combination of PV and conventional gas CTs provides a lower net cost compared to CSP-TES and PV with batteries. Some configurations of CSP-TES have a lower net cost than PV with batteries for even the lowest battery cost estimate. Using projected capital cost targets, however, some configurations of CSP-TES have a lower net cost than PV with either option for even the lowest battery cost estimate. The net cost of CSP-TES varies with configuration, and lower solar multiples coupled with less storage are more attractive at current cost levels, due to high component costs. However, higher solar multiples show a lower net cost using projected future costs for heliostats and thermal storage materials.

14 SOLAR ENERGY↗
DOE OSTI2019

Technoeconomic and Life-Cycle Analysis of Single-Step Catalytic Conversion of Wet Ethanol into Fungible Fuel Blendstocks

Technoeconomic and life-cycle analyses are presented for catalytic conversion of ethanol to fungible hydrocarbon fuel blendstocks, informed by advances in catalyst and process development. Whereas prior work toward this end focused on 3-step processes featuring dehydration, oligomerization, and hydrogenation, the consolidated alcohol dehydration and oligomerization (CADO) approach described here results in 1-step conversion of wet ethanol vapor (40 wt% in water) to hydrocarbons and water over a metal-modified zeolite catalyst. A development project increased liquid hydrocarbon yields from 36% of theoretical to >80%, reduced catalyst cost by an order of magnitude, scaled up the process by 300-fold, and reduced projected costs of ethanol conversion 12-fold. Current CADO products conform most closely to gasoline blendstocks, but can be blended with jet fuel at low levels today, and could potentially be blended at higher levels in the future. Operating plus annualized capital costs for conversion of wet ethanol to fungible blendstocks are estimated at $2.00/GJ for CADO today and $1.44/GJ in the future, similar to the unit energy cost of producing anhydrous ethanol from wet ethanol ($1.46/GJ). Including the cost of ethanol from either corn or future cellulosic biomass but not production incentives, projected minimum selling prices for fungible blendstocks produced via CADO are competitive with conventional jet fuel when oil is $100 per barrel but not at $60 per barrel. However, with existing production incentives, the projected minimum blendstock selling price is competitive with oil at $60 per barrel. Life-cycle greenhouse gas emission reductions for CADO-derived hydrocarbon blendstocks closely follow those for the ethanol feedstock.

09 BIOMASS FUELS↗
DOE OSTI2021

Cost Drivers for a Tokamak-Based Compact Pilot Plant

A comprehensive systems code that includes a range of physics and engineering considerations along with a simplified costing model has been utilized to evaluate the primary cost drivers for a compact tokamak pilot plant. The systems code has been benchmarked against several tokamak reactor designs and is utilized with sophisticated optimization algorithms to develop optimal solutions for a set of user-specified assumptions and design constraints. Here, in contrast to previous models that have focused on the cost of electricity as the key cost metric, this study uses the estimated capital cost of the facility. The analysis suggests that a pilot plant with the following features may offer potential for a cost-attractive pilot plant: A ~ 3, H 98y2 > 1.5, P net = 200 MW, 𝜏 𝑝⁢𝑢⁢𝑙⁢𝑠⁢𝑒 ~ 1 to 2 h utilizing rare-earth barium copper oxide (REBCO) magnet technology and a plug-bucked central solenoid/toroidal field (CS/TF) magnet support structure. While REBCO magnets offer some advantages relative to Nb 3 Sn magnets in all cases, the most gain is obtained when combined with the plug-bucked CS/TF bucking solution. Pulsed operation reduces capital cost requirements relative to steady-state operation, especially at low confinement. Cost sensitivity studies indicate that there are significant cost uncertainties associated with the achievable confinement quality, tritium breeding capability, attainable thermal efficiency, and achievable neutron wall loading, suggesting that these areas are the most critical areas in reducing the cost risk for a compact tokamak pilot plant. Further cost sensitivity studies indicate that the estimated cost is most sensitive to the underlying cost of the magnetic coils, providing further impetus to better establish cost-effective means for producing fusion magnets.

Compact pilot plant↗
DOE OSTI2024

Tax Credits for Clean Electricity: The Distributional Impacts of Supply-Push Policies in the Power Sector

We evaluate distributional and efficiency consequences of the bulk power clean electricity tax credits authorized by the 2022 Inflation Reduction Act. To do so, we link detailed electricity capacity expansion, computable general equilibrium, microsimulation, and air pollution models to estimate economic welfare and health incidence across demographic groups. We evaluate trade-offs between policy efficiency and income progressivity by comparing the tax credits to cap-and-trade policies. The tax credits encourage increased clean electricity investment, resulting in a reallocation of capital from elsewhere in the economy, higher prices for capital and other goods, lower power prices, and lower emissions. The tax credits yield progressive outcomes for economic welfare at the expense of efficiency while all modeled policies demonstrate progressivity in health impacts. The health benefits, absent climate benefits, exceed total policy costs and provide greater benefits for low-income and historically marginalized households given coincidence of household locations and emissions exposure intensity.

distributional impacts↗
DOE OSTI2022

Fusion pilot plant performance and the role of a sustained high power density tokamak

Here, recent U.S. fusion development strategy reports all recommend that the U.S. should pursue innovative science and technology to enable construction of a fusion pilot plant (FPP) that produces net electricity from fusion at low capital cost. Compact tokamaks have been proposed as a means of potentially reducing the capital cost of a FPP. However, compact steady-state tokamak FPPs face the challenge of integrating a high fraction of self-driven current with high core confinement, plasma pressure, and high divertor parallel heat flux. This integration is sufficiently challenging that a dedicated sustained-high-power-density (SHPD) tokamak facility is proposed by the U.S. community as the optimal way to close this integration gap. Performance projections for the steady-state tokamak FPP regime are presented and a preliminary SHPD device with substantial flexibility in lower aspect ratio (A = 2–2.5), shaping, and divertor configuration to narrow gaps to an FPP is described.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2026

Tokamak Energy’s pre-concept design for a fusion power plant: an overview of ST-E1

Climate change and rapidly rising energy demand, driven in part by artificial intelligence and data-centre growth, create an urgent need for stable, low-carbon, and abundant power. Fusion is a promising long-term solution, yet its commercialisation faces a fundamental paradox in today’s investment environment: pilot plants are essential to de-risk physics, engineering, and operations, but their limited lifetime energy output and high upfront costs make them difficult to finance. This paper presents Tokamak Energy’s response: ST-E1, a pre-concept design for a low-aspect-ratio tokamak power plant engineered specifically to overcome this challenge. ST-E1 is designed from the outset for phased operation—pilot and commercial phases, with an upgrade phase in between—with emphasis on commercial viability, maintainability, nuclear engineering, modularity, and upgradability. A key design principle is the deliberate separation of long-lived assets, such as the magnet cage and vacuum vessel, from replaceable in-vessel systems. This provides an attractive and credible investment approach to generate operational data and de-risk key technologies while preserving most capital-intensive assets for later commercial phases. The architecture supports continuous optimisation toward high net electric power (targeting 800–1000 MW net electric), a normalised capital expenditure of $\$$ 12–14k/kW of net electric power, and high availability (targeting > 80%). A tokamak core with a 5 m major radius, aspect ratio of 2.3, and on-plasma axis toroidal field of 5.25 T was selected to meet these objectives. This paper summarises the ST-E1 design philosophy, principal features, and development methodology. It introduces a Focus Collection of 11 papers detailing the pre-concept design of the entire tokamak and corresponding plant.

ST-E1↗
DOE OSTI2025

A model for selecting the best sustainable airport technology alternatives

Air transport is a continually expanding industry, a fact that has become even more evident with the recovery of the aviation industry post-COVID-19. This expansion amplified energy consumption at airports, which was already significantly high. Airport decision-makers are increasingly focusing on improving sustainability and addressing social, economic, and environmental criteria across airports worldwide. In this article, we propose a decision-making model for identifying a sustainable airport technology solution that minimizes the energy consumption of airport lighting while considering economic, emission, and life-cycle criteria. The proposed model combines data envelopment analysis and multi-criteria decision making techniques. We applied the model to the Dallas/Fort Worth International Airport (DFW) as a case study, considering eight lighting technology solutions, each with five luminous flux alternatives. Our model identified the best lighting technology solution for DFW outdoor and indoor environments based on the following criteria: luminous flux, capital costs, life-cycle costs, energy consumption, and emissions (CO2e, NOx, SO2, and PM2.5). The designed model is customizable to any airport and is applicable to a wide range of airport lighting technologies. In our analysis, Light-Emitting Diode lighting emerged as the most sustainable technology option. It ranked first in most cases due to its balance of high efficacy, long lifespan, low life-cycle cost, low capital cost, and lower emissions across all pollutants.

Tchivwila, Moise B↗
DOE OSTI2015

HPCCloud: A Cloud/Web-Based Simulation Environment

Advanced modeling and simulation has enabled the design of a variety of innovative products and the analysis of numerous complex phenomenon. There are significant barriers to widespread adoption of these tools. In particular, advanced modeling and simulation: (1) is considered complex to use, (2) needs in-house expertise, and (3) requires high capital costs. In this paper, we describe the development of an end-to-end, advanced modeling and simulation cloud platform that encapsulates best practices for scientific computing in the cloud, and demonstrate using Hydra-TH as a prototypical application. As an alternative to traditional advanced modeling and simulation workflows, our Web-based approach simplifies the processes, decreases the need for in-house computational science and engineering experts, and lowers the capital investments. In addition to providing significantly improved, intuitive software, the environment offers reproducible workflows where the full lifecycle of data from input to final analyzed results can be saved, shared, and even published.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2017

A Distributed Middleware Architecture for Attack-Resilient Communications in Smart Grids

Distributed Energy Resources (DERs) are being increasingly accepted as an excellent complement to traditional energy sources in smart grids. As most of these generators are geographically dispersed, dedicated communications investments for every generator are capital cost prohibitive. Real-time distributed communications middleware, which supervises, organizes and schedules tremendous amounts of data traffic in smart grids with high penetrations of DERs, allows for the use of existing network infrastructure. In this paper, we propose a distributed attack-resilient middleware architecture that detects and mitigates the congestion attacks by exploiting the Quality of Experience (QoE) measures to complement the conventional Quality of Service (QoS) information to detect and mitigate the congestion attacks effectively. The simulation results illustrate the efficiency of our proposed communications middleware architecture.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

Solid-State Transformer and Hybrid Transformer With Integrated Energy Storage in Active Distribution Grids: Technical and Economic Comparison, Dispatch, and Control

Solid-state transformer (SST) and hybrid transformer (HT) are promising alternatives to the line-frequency transformer (LFT) in smart grids. The SST features medium-frequency isolation, full controllability for voltage regulation, reactive power compensation, and the capability of battery energy storage system (BESS) integration with multiport configuration. The HT has a partially-rated converter for fractional controllability and can integrate a small BESS. Fast grid-edge voltage fluctuations from increased solar photovoltaic (PV) and electric vehicle (EV) penetration are difficult to manage for mechanical load tap changers. Hence, along with the trend towards more BESS in the grid, the controllability and the storage integration capability of the SST and HT are of strong interest. However, a review of literature shows existing SST and HT research is mostly at converter level, while system-level assessments are scarce. Assessing technical and economic impacts is critical to understanding the benefits and role of the SST and HT to guide future research, which is presented for the first time in this article. Experimental results from medium-voltage (MV) SST and MV HT prototypes are shown to confirm equipment-level feasibility, where the voltage controllability waveforms of a MV HT prototype are reported for the first time. Comparative simulations are performed on a modified IEEE 34-bus system. Here, a grid-model-less decentralized grid-edge voltage control method and a day-ahead BESS dispatch method are proposed for the SST and HT. The simulations show that the SST and HT with integrated storage can host more PV, achieve peak shaving, mitigate voltage fluctuation and reverse power flow, and support energy arbitrage for operational cost reduction, as compared to the LFT. Moreover, comprehensive analyses of net present value (NPV) and internal rate of return (IRR) are performed under different installed PV capacities, HT’s partial converter ratings, and BESS capacities. Sensitivities to future cost reductions of the PV and BESS are studied. Although the NPV and IRR are currently negative, 60% capital cost reduction or 150% revenue increase will make the SST and HT economically viable in the use case studied.

14 SOLAR ENERGY↗