Capital Investment Costs Research Articles

Optimal capacity determination of photovoltaic and energy storage systems for electric vehicle charging stations

With the growing interest in integrating photovoltaic (PV) systems and energy storage systems (ESSs) into electric vehicle (EV) charging stations (ECSs), extensive research has focused on methods to increase the profits of ECS operators (ECSOs). Conventional studies have primarily relied on empirical methods, such as assuming a constant value for the power conversion system (PCS) capacity or modeling it as being dependent on the battery capacity, to design ESSs. However, such empirical methods can lead to suboptimal or excessive determinations of the capacity of a facility. This study proposes a battery-independent PCS model that independently models the battery and PCS capacities in ESS design to overcome the limitations of the conventional model and maximize the profit for ECSOs. The proposed model determines the optimal capacity of ESS and PV to maximize ECSO's profit. The nonlinearities that arise from using a battery-independent PCS model are linearized by the BIG-M method to effectively solve the optimization problem. The proposed model achieved an additional profit of up to 1.5 % compared to the conventional model. Additionally, the proposed model was simulated under various conditions (e.g., decreasing capital investment costs of ESS, changing EV charging demand, changing time-of-use rates, and applying real-time price rates). Accordingly, it is confirmed that the proposed model greatly contributes to improving ECSO profit even under various conditions. Moreover, the proposed model offers a means to determine the optimal capacities of PV and ESS in an ECS, ultimately maximizing ECSO profits.

An Analysis of Industry Forces Impacting Apple’s Performance: A Study Using Porter’s Five Forces Framework

The main objective of this study was to identify different electronic industry forces that impact the performance of Apple Inc. using Porter’s five forces framework. The study adopted a desktop methodology. The buyers have moderate power as a result of customers' attraction to the brand. Still, also the availability of alternative products at lower prices gives the customers power to negotiate. There is a moderate power of supplies resulting from a wide industry demand and scarcity of the components. There is a low threat of new entrants in the electronic industry due to high capital investment, high research and development costs, economies of scale and strong brand loyalty. The availability of different products of similar functionalities makes the threat of substitutes to be high in the market like tablets and smartphones. The rivalry of existing competitors is high as the industry is characterized by aggressive price strategies. To maintain its strong position in the market, Apple highly invests in research and development to make its products differentiated and maintains its strong brand loyalty. Apple need to consider the consumers of low incomes as the products of Apple Inc. are regarded as expensive for this group and where the competitors are willing to offer substitute products and services at lower prices.

Design and economic analysis of an innovative multi-generation system in different Countries with diverse economic contexts

This paper presents an innovative trigeneration system designed to maximize energy utilization by simultaneously producing power, cooling, and freshwater. The system integrates multiple energy sources, including biomass, natural gas, and geothermal energy, and comprises a modified gas turbine cycle, a geothermal power plant, a triple-effect absorption refrigeration cycle, and a multi-effect desalination unit. Performance metrics are evaluated from both thermodynamic and economic perspectives across four case studies: Australia, the USA, China, and Russia. The economic feasibility analysis utilizes real-state economic data, incorporating natural gas prices, electricity prices for households, interest rates, and inflation rates specific to each country. The system achieved impressive outputs, with net power, cooling, and freshwater production rates of 6299 kW, 140.1 kW, and 13.41 kg/s, respectively. Exergy analysis revealed that the combustion chamber, heat exchanger, and multi-effect desalination units exhibit the highest irreversibility, with exergy destruction rates of 2961 kW, 1125 kW, and 995.3 kW, respectively. The fixed capital investment cost is estimated at $13.5 million, resulting in a payback period of 6.75 years and a net present value of $7.287 million. In Australia, the system demonstrated a particularly favorable economic performance, with a payback period of 3.98 years and a net present value of $36.19 million. Conversely, in China, the payback period exceeds the system's expected lifetime, highlighting the economic challenges in certain environments. These results underscore the system's potential for profitability and sustainability, particularly in regions with favorable economic conditions.

Improving the Economic Feasibility of Small-Scale Biogas-Solid Oxide Fuel Cell Energy Systems through a Local Ugandan Biochar Production Method

A small-scale (up to 5 kWe) biogas-solid oxide fuel cell (SOFC) energy system is an envisioned system, which can be used to meet both electrical and thermal energy demand of off-grid settlements. SOFC systems are reported to be more efficient than alternatives like internal combustion engines (ICE). In addition to energy recovery, implementation of biogas-SOFC systems can enhance sanitation among these settlements. However, the capital investment costs and the operation and maintenance costs of a biogas-SOFC energy system are currently higher than the existing alternatives. From previous works, H2S removal by biochar was proposed as a potential local cost-effective alternative. This research demonstrates the techno-economic potential of locally produced biochars made from cow manure, jackfruit leaves, and jack fruit branches in rural Uganda for purifying the biogas prior to SOFC use. Results revealed that the use of biochar from cow manure and jack fruit leaves can reduce H2S to below the desired 1 ppm and substitute alternative biogas treatments like activated carbon. These experimental results were then translated to demonstrate how this biochar would improve the economic feasibility for the implementation of biogas-SOFC systems. It is likely that the operation and maintenance cost of a biogas-SOFC energy system can in the long run be reduced by over 80%. Also, the use of internal reforming as opposed to external reforming can greatly reduce the system capital cost by over 25% and hence further increase the chances of system economic feasibility. By applying the proposed cost reduction strategies coupled with subsidies such as tax reduction or exemption, the biogas-SOFC energy system could become economically competitive with the already existing technologies for off-grid electricity generation, like solar photovoltaic systems.

Solar irrigation potential in Sub-Saharan Africa: a crop-specific techno-economic analysis

In this study, we introduce an integrated modeling framework that combines a hydrologic model, a biophysical crop model, and a techno-economic model to assess solar irrigation potential in Sub-Saharan Africa (SSA) based on seven commonly grown food crops-maize, wheat, sorghum, potato, cassava, tomato, and onion. The study involves determining the irrigation requirements, location-specific capital investment costs, crop-specific profitability, and the cropland area under various cost scenarios (low and high) and soil fertility (low, moderate, near-optimal, and optimal) scenarios. Our research reveals considerable potential for solar irrigation, with profitability and viable cropland areas that vary according to crop type, irrigation system cost scenarios, and soil fertility levels. Our assessment shows that approximately 9.34 million ha of SSA’s current rainfed cropland are hydrologically and economically feasible for solar irrigation. Specifically, maize and onion display the lowest and highest viability, spanning 1–4 million ha and 29–33 million ha, respectively, under optimal soil fertility conditions. In terms of profitability, maize and onion rank as the least and most economically viable crops for solar irrigation, yielding average annual returns of $50-$125/ha and $933-$1450/ha, respectively, under optimal soil fertility conditions. The lower and upper bounds of profitability and cropland range correspond to high-cost and low-cost scenarios, respectively. Furthermore, our study reveals distinct regional differences in the economic feasibility of solar irrigation. Eastern Africa is more economically favorable for maize, sorghum, tomato, and cassava. Central Africa stands out for onion cultivation, whereas West and Southern Africa are more profitable for potato and wheat, respectively. To realize the irrigation benefits highlighted, an energy input of 940-2,168 kWh/ha/yr is necessary, varying by crop and geographic sub-region of the SSA sub-continent. Our model and its results highlights the importance of selecting the right crops, applying fertilizers at the appropriate rates, and considering regional factors to maximize the benefits of solar irrigation in SSA. These insights are crucial for strategic planning and investment in the region’s agricultural sector.

An integrated approach to green power, cooling, and freshwater production from geothermal and solar energy sources; case study of Jiangsu, China

This paper introduces an innovative integration of geothermal and solar energies to assess the production of power, cooling, and freshwater. These products are achieved through a modified absorption refrigeration cycle, a modified organic Rankine cycle, and humidification-dehumidification subsystems driven by a flash-binary configuration. The performance of the setup is evaluated using both thermodynamic and economic approaches. Additionally, three multi-objective optimizations are applied to determine a suitable optimal state. The approaches reveal net power, cooling, and freshwater production rates of 807.3 kW, 1345 kW, and 7.96 kg/s, respectively. The designed setup requires a total capital investment cost of $2,490,310 and has a payback period of 5.76 years in the base mode. The study highlights that the temperature difference of superheating significantly impacts the total capital investment cost and exergy efficiency, while the cooling production is mainly influenced by the evaporator temperature. The final optimal state achieved an exergy efficiency of 15.98 % and a net present value of $1,999,864. Overall, this innovative hybrid geothermal-solar setup demonstrates a viable solution for sustainable energy production, combining power generation, cooling, and freshwater production in a single integrated system. The findings support the system's potential for real-world applications, particularly in regions with suitable geothermal and solar resources.

Continuous CO2 capture and reduction to CO by circulating transition-metal-free dual-function material in fluidized-bed reactors

To mitigate global warming and achieve a sustainable society, innovative technologies for efficient CO2 utilization are required. Integrated CO2 capture and reduction (CCR) using dual-function materials (DFMs) is favorable owing to its potentially low energy consumption, capital investment, and processing costs. Although numerous studies have focused on catalytic science, continuous and steady-state CCR operations have not been sufficiently addressed from an engineering perspective. In this study, a circulating fluidized bed (CFB) system is investigated for continuous CCR to syngas (CO + H2). In the CFB system, transition-metal-free DFM (Na/Al2O3) particles are circulated between two bubbling fluidized-bed reactors. The DFM captures CO2 in one reactor (CO2 capture reactor) and reduces the captured CO2 to CO by the reaction with H2 in the other reactor (H2 reactor). The effluent gas concentrations from both reactors reach steady state and are maintained for over 8 h. For the product gas from the H2 reactor, the CO2 conversion and CO selectivity exceed 80 % and 99 %, respectively. However, the H2 conversion is <20 %, indicating a potential challenge for the CFB system for integrated CCR. Furthermore, this study confirms that the H2/CO ratio for syngas can be controlled by adjusting the experimental conditions (particularly, the H2 flow rate). Consequently, the CFB system can be modified to facilitate the interaction between H2 gas and the DFM particles.

The Integration of Renewable Energy into a Fossil Fuel Power Generation System in Oil-Producing Countries: A Case Study of an Integrated Solar Combined Cycle at the Sarir Power Plant

Libya is facing a serious challenge in its sustainable development because of its complete dependence on traditional fuels in meeting its growing energy demand. On the other hand, more intensive energy utilization accommodating multiple energy resources, including renewables, has gained considerable attention. This article is motivated by the obvious need for research on this topic due to the shortage of applications concerning the prospects of the hybridization of energy systems for electric power generation in Libya. The 283 MW single-cycle gas turbine operating at the Sarir power plant located in the Libyan desert is considered a case study for a proposed Integrated Solar Combined Cycle (ISCC) system. By utilizing the common infrastructure of a gas-fired power plant and concentrating solar power (CSP) technology, a triple hybrid system is modeled using the EES programming tool. The triple hybrid system consists of (i) a closed Brayton cycle (BC), (ii) a Rankine cycle (RC), which uses heat derived from a parabolic collector field in addition to the waste heat of the BC, and (iii) an organic Rankine cycle (ORC), which is involved in recovering waste heat from the RC. A thermodynamic analysis of the developed triple combined power plant shows that the global power output ranges between 416 MW (in December) and a maximum of 452.9 MW, which was obtained in July. The highest overall system efficiency of 44.3% was achieved in December at a pressure ratio of 12 and 20% of steam fraction in the RC. The monthly capital investment cost for the ISCC facility varies between 52.59 USD/MWh and 58.19 USD/MWh. From an environmental perspective, the ISCC facility can achieve a carbon footprint of up to 319 kg/MWh on a monthly basis compared to 589 kg/MWh for the base BC plant, which represents a reduction of up to 46%. This study could stimulate decision makers to adopt ISCC power plants in Libya and in other developing oil-producing countries.

Extended Aquifer System Pressure Behavior under Carbon Storage

Summary Most reported carbon storage projects have involved inexpensive carbon dioxide (CO2) capture from gas processing plants or ethanol refineries. However, widespread carbon capture and storage (CCS) application must avoid any risk that high capital investment cost for carbon capture from stationary point sources leads to unanticipated issues related to the aquifer storage. This paper reviews successful and unsuccessful carbon storage projects and explains simple extended aquifer system fundamentals that must be considered in selecting a storage aquifer. This study begins by evaluating reported carbon storage projects in the context of an extended aquifer system with specific attention to initial formation pore pressure and potential or known hydraulic vertical or lateral communication with hydrocarbon accumulations and/or fresh water. Further study focuses on how the contrast between injection well and aquifer pressure evolution enables understanding of the overall aquifer material balance. Finally, we consider implications of brine migration during and after long-term CO2 injection in unconfined aquifers. Experience in the petroleum industry with aquifer behavior includes presence or lack of water influx and production from hydrocarbon reservoirs that share a common aquifer. Of particular importance is the observation that hydrostatic initial formation pressure indicates the possibility that a petroleum system, or an extended aquifer system without hydrocarbon accumulation(s), connects to atmospheric pressure through an unconfined aquifer. In such cases, indefinite injection will never increase the regional aquifer pressure. Furthermore, initial formation pressure that exceeds hydrostatic pressure implies a petroleum system or an extended aquifer system that is volumetrically limited. In such cases, injection will increase the system pressure, and pressure monitoring can detect leakage from the system. Finally, CO2 injection into an aquifer will displace brine in the direction of lower pressure that could relate to distant production from the same aquifer or from hydrocarbon reservoirs with which it communicates. Reasons for known carbon storage project interruptions have included unexpected lateral plume migration or aquifer pressure increase during CO2 injection that might have been anticipated with attention to straightforward consideration of aquifer-enabled hydraulic communication. Such extended aquifer dynamics must be included in long-term models for permanent CO2 storage during and after injection.

Trends in Hybrid Renewable Energy System (HRES) Applications: A Review

Microgrids and hybrid renewable energy systems play a crucial role in today’s energy transition. They enable local power generation and distribution, reducing dependence on large centralized infrastructures, can operate independently or connected to a grid, and can provide backup power, thus increasing system resilience. In addition, they combine multiple renewable energy sources, such as solar, wind, hydro, and biomass, to maximize the efficiency and reliability of the supply, and are also adaptable to location-specific conditions, taking advantage of locally available energy resources and reducing the need for energy imports. Moreover, they contribute to decarbonization goals by offering a cleaner and more sustainable alternative. In this article, a documentary review is presented on the interaction of Homer Pro software 3.16.2 (July 2023), used for the design of hybrid renewable energy systems (HRES), with other methods of optimization or sizing. Allusion is made to the type of architecture in the most prominent clean and fossil source configurations, the levelized cost, net annual cost, and maintenance and capital investment cost. A comparison is made among the works reported in the last five years regarding the use of this software tool, based on load demand, geographical area, renewable energy sources, fossil sources, and objective functions, applied to the educational, rural, and industrial sectors. It is shown that India is one of the countries that has reported the most number of HRES techno-economic environmental analysis works, and that the case studies have focused approximately 47% on rural areas, 20% on educational agencies, 14% on commerce and industry, and 29% on urban buildings.

Key barriers and mitigation strategies towards sustainable prefabricated construction – a case of developing economies

PurposeThe present study aims to identify significant barriers to adopting prefabricated construction (PFC) in developing economies using a study in Sri Lanka and develop an integrated strategy framework to mitigate and overcome the obstacles.Design/methodology/approachThe research process included a comprehensive literature review, a pilot study, a questionnaire survey for data collection, statistical analysis and a qualitative content analysis.FindingsRanking method revealed that all 23 barriers were significant. Top significant barriers include challenges in prefabricated component transportation, high capital investment costs and lack of awareness of the benefits of PFC among owners/developers. Factor analysis clustered six barrier categories (BCs) that fit the barrier factors, explaining 71.22% of the cumulative variance. Fuzzy synthetic evaluation revealed that all BCs significantly influence PFC adoption in Sri Lanka. Finally, the proposed mitigation strategies were mapped with barriers to complete the integrated framework.Practical implicationsThe study outcomes are relevant to construction industry stakeholders of Sri Lanka, who are keen to enhance construction efficiencies. The implications can also benefit construction industry stakeholders and policymakers to formulate policies and regulations and identify mitigation solutions.Originality/valueThe study provides deeper insights into the challenges to adopting prefabrication in South Asian countries such as Sri Lanka. Furthermore, the integrated framework is a novel contribution that can be used to derive actions to mitigate barriers in developing economies.

Life cycle emissions and unit production cost of sustainable aviation fuel from logging residues in Georgia, United States

Production of Sustainable Aviation Fuel (SAF) has gained popularity for reducing carbon emissions from the aviation sector. To evaluate the environmental and economic tradeoffs related to SAF production and its potential use, this study estimates the life cycle carbon emissions and unit production cost of SAF produced from logging residues generated during harvest and thinning operations in Georgia, a major roundwood producing state in the Southern United States. We considered two production pathways, i.e., Ethanol-to-Jet (ETJ) and Iso-Butanol-to-Jet (Iso-BTJ), to compute the carbon savings and unit production costs. A sensitivity analysis was performed to identify significant factors contributing to the overall carbon savings and unit production costs for the selected pathways. After considering revenues generated from co-products, the minimum aviation fuel selling price (MASP) was $2.71 L-1 and $2.44 L-1 for ETJ and Iso-BTJ pathways, respectively. Capital investment cost at biorefinery accounted for most of the MASP, followed by the minimum haul rate for transporting biomass and variable cost for alcohol intermediate production. Finally, after considering tax credit from the Inflation Reduction Act of 2022 and RIN (Renewable Identification Number) credit along with co-product revenue, the MASP ranged between $2.29 L-1 and 0.83 L-1 for the ETJ pathway and between $2.04 L-1 and $0.59 L-1 for the Iso-BTJ pathway. In addition, the carbon intensity of both the ETJ and Iso-BTJ pathways were 758 g CO2e L−1 and 976 g CO2e L−1, with relative carbon savings of 70.6 % and 62.1 % compared to conventional aviation fuel. The production cost suggests a minimum abatement cost of $59 t CO2e−1 for the ETJ and -$59.3 t CO2e−1 for the Iso-BTJ pathways in the presence of federal incentives. Our study shows that logging residues-based SAF could reduce the overall carbon footprint of the aviation sector; however, policy support is needed to support its production in light of higher production costs.

Enhancing sustainable ethanol fuel production from cassava in Vietnam

This study focused on developing a comprehensive model to perform techno-economic analysis and calculate greenhouse gas emissions and net energy balance of cassava-based ethanol production in Vietnam. Four steps were involved in this study: (1) collecting data on the cassava-based ethanol conversion pathway, (2) modeling an ethanol production plant, (3) calculating greenhouse gas emissions and net energy balance, and (4) evaluating economic feasibility. The total capital investment and production cost per liter of ethanol are 0.6 $/l/yr and 0.4 $/l, respectively. The fossil energy consumption and net energy ratio during cultivation, transportation, production, and use of ethanol are 12.4 MJ/l and 1.70, respectively. The total greenhouse gas emissions of cassava-based ethanol production are 1252 gCO2eq/l or 59.1 gCO2eq/MJ, which equals 63 % of greenhouse gas emissions from gasoline. This finding confirms that cassava-based ethanol can be an alternative fuel based on economic feasibility and environmental benefit by reducing greenhouse gas emissions in Vietnam.

Financing mechanism for solid waste management in Anambra, Nigeria: analyses of emerging challenges and implication for circular economy.

Waste management is a critical public service provided by municipalities around the world. It is often problematic, inefficient, and abysmally performed in developing countries. Among the problems associated with waste management in these global locations is the issue of finance. Finance is required for both capital investment and operational costs. Methods of waste management financing differ from place to place due to cultural, political, and socio-economic peculiarities. Understanding these conditionalities is necessary to be able to proffer sustainable solutions. Despite these facts, there is limited comprehensive and relevant academic literature on waste management financing mechanisms in developing countries both in the past and recent times. This work addresses a significant gap in the literature by studying the mechanism for waste management financing in developing countries using Anambra State, Nigeria, as a case study. The current study further investigated the associated challenges and opportunities and made critical discussions on the implications on the circular economy. User fees and subsidies from the government are the major financing sources. The absence of cost-revenue model analysis, economic and institutional volatility, the unwillingness of the service users to pay fees, and lack of transparency are major challenges to the financial sustainability of waste management in the studied context. The creation of incentives for behavioral changes, adoption of neo-liberal policies, and formal integration of informal waste pickers are factors that can minimize the cost of waste management services while promoting a circular economy.

A supplementary labor cost model for estimating the fixed capital cost of commercial-scale algae photobioreactors plants

Scaling up algae photobioreactors (PBR) for commercial production presents challenges in estimating fixed capital investment costs, particularly the labor costs associated with installing low-cost equipment. Using fractions of the equipment cost to estimate the installation labor cost does not necessarily provide a representative estimate for the labor cost as the labor required is no longer proportionate to the equipment cost. In this study, we developed a supplementary labor cost model to estimate equipment installation and overhead costs for scaling up algae PBRs using a manufacturing cost estimation approach. The model consists of four main steps: identifying and sequencing all processes, estimating labor time using the Methods-Time Measurement procedure, estimating process time, and calculating the overall labor cost. As a proof-of-concept, a pilot-sized PBR has been adapted from the literature to illustrate how to implement these four steps to estimate the labor cost for the commercial size. The model provides more accurate labor cost for fixed capital cost estimation to supplement existing fixed capital cost estimation methods. The model also provides insights into the main cost drivers in the equipment installation process that can be used for bioreactor redesign and further capital cost reduction.

Sustainable rural electrification: small hydropower stations, electrification and rural welfare improvement in Tanzania

PurposeTanzania is rich in small hydropower (SHP) potentials. However, many of these potentials have yet to be fully used, and more than two-thirds of its rural population lacks access to electricity. The purpose of this paper is to explore the role of SHP stations in improving rural welfare in the southern highlands of Tanzania. It further explores the history, cost-effective analysis and threats to the sustainability of SHP as one of the renewable energy sources.Design/methodology/approachThe study uses a qualitative research design to explore respondents’ views on the role of SHP stations in facilitating rural electrification and welfare improvement. Primary data were gathered using semi-structured interviews with the 27 key informants and beneficiaries of SHP stations from the Southern Highlands of Tanzania. In addition, the study used documentary research to complement the information from the field survey.FindingsThe findings found that SHP stations enhance rural electrification and welfare by providing electricity in remote areas with sparse populations. They operate as standalone off-grids, often by church communities and individuals. However, the sustainability of SHP stations is hampered by challenges such as climate change impacts, high capital investment costs, heavy siltation of small reservoirs, skilled manpower shortages, limited local manufacturing capabilities and infrastructural issues.Originality/valueThe study contributes to the ongoing debate on renewable energy supply and uses, focusing on how SHP stations could contribute to sustainable rural electrification and achieve the 2030 United Nations agenda for sustainable development, which, among other things, aims to safeguard access to sustainable and modern energy and alleviate energy poverty.

Evaluating the Potential of Hydrogen Production from Agricultural Waste in Indonesia: A Comparative Techno-economic Analysis

Hydrogen production from agricultural waste is a potentially established industry in Indonesia, and the government aims to introduce innovative technologies to produce hydrogen. This study aimed to explore the feasibility of hydrogen production from agricultural waste using three different methods: SCWG, fermentation, and gasification. The analysis focuses on comparing the price of hydrogen as a product by setting the same value of the IRR at 30%. The simulation was conducted by analyzing the capacity of hydrogen production at 3650 tons/year. The results of this study demonstrate that fermentation is the most feasible technology for producing hydrogen from agricultural wastes in Indonesia. In this technology, the price of hydrogen obtained was $5.65/kg, with a total capital investment (TCI) and production cost (TPC) of $10,756,132.97 and $13,977,351.97, respectively. Based on this simulation, the other parameter values, including NPV, ROI, and PoT, were $15,387,688.72, 68%, and 2.27 years, respectively. These results indicate that the establishment of hydrogen production in Indonesia using fermentation technology and agricultural waste is economically viable.

A strategic sustainability model for global luxury companies in the management of CO2 emissions

Luxury brands are at the forefront of sustainability efforts and carbon emission reductions to fight climate change. The goal of this paper is to analyze such climate change challenges in terms of cost efforts within large luxury conglomerates. In doing so, financial metrics have been gathered for the top 100 companies in the luxury sector and compared against CO2 emissions metrics with regressive methods. This enables the study of relationships between sustainability and finance to explore if sustainability is expensive and if sustainability is explained by costs, sales, taxes, or investment. Such works allow the setting of conclusions on financial and managerial decisions and, moreover, set a new framework of analysis based on financial variables and the positive or negative impact on CO2 emissions, such as which financial variables generate more CO2 emissions (luxury sales, capital investment and financial cost) and which help to reduce such emissions (cost of goods sold, general expenses and taxes).

Economic and environmental benefits of automated electric vehicle ride-hailing services in New York City

A precise, scalable, and computationally efficient mathematical framework is proposed for region-wide autonomous electric vehicle (AEV) fleet management, sizing and infrastructure planning for urban ride-hailing services. A comprehensive techno-economic analysis in New York City is conducted not only to calculate the societal costs but also to quantify the environmental and health benefits resulting from reduced emissions. The results reveal that strategic fleet management can reduce fleet size and unnecessary cruising mileage by up to 40% and 70%, respectively. This alleviates traffic congestion, saves travel time, and further reduces fleet sizes. Besides, neither large-battery-size AEVs nor high-power charging infrastructure is necessary to achieve efficient service. This effectively alleviates financial and operational burdens on fleet operators and power systems. Moreover, the reduced travel time and emissions resulting from efficient fleet autonomy create an economic value that exceeds the total capital investment and operational costs of fleet services.

Upscaling Plasma-Based CO2 Conversion: Case Study of a Multi-Reactor Gliding Arc Plasmatron.

Atmospheric pressure plasmas have shifted in recent years from being a burgeoning research field in the academic setting to an actively investigated technology in the chemical, oil, and environmental industries. This is largely driven by the climate change mitigation efforts, as well as the evident pathways of value creation by converting greenhouse gases (such as CO2) into useful chemical feedstock. Currently, most high technology readiness level (TRL) plasma-based technologies are based on volumetric and power-based scaling of thermal plasma systems, which results in large capital investment and regular maintenance costs. This work investigates bringing a quasi-thermal (so-called "warm") plasma setup, namely, a gliding arc plasmatron, from a lab-scale to a pilot-scale capacity with an increase in throughput capacity by a factor of 10. The method of scaling is the parallelization of plasmatron reactors within a single housing, with the aim of maintaining a warm plasma regime while simultaneously improving build cost and efficiency (compared to separate reactors operating in parallel). Special attention is also given to the safety and control features implemented in the setup, a key component required for integration into industrial systems. The performance of the multi-reactor gliding arc plasmatron (MRGAP) reactor is investigated, focusing on the influence of flow rate and the number of active reactors. The location of active reactors was deemed to have a negligible effect on the monitored metrics of conversion, energy efficiency, and energy cost. The optimum operating conditions were found to be with the most active reactors (five) at the highest investigated flow rate (80 L/min). Analysis of results suggests that an optimum conversion (9%) and plug power-based energy efficiency (19%) can be maintained at a specific energy input (SEI) around 5.3 kJ/L (or 1 eV/molecule). The concept of parallelization of plasmatron reactors within a singular housing was demonstrated to be a viable method for scaling up from a lab-scale to a prototype-scale device, with performance analysis suggesting that increasing the power (through adding more reactor channels) and total flow rate, while maintaining an SEI around 5.3 or 4.2 kJ/L, i.e., 1.3 or 1 eV/molecule (based on plug power and plasma-deposited power, respectively), can result in increased conversion rate without sacrificing absolute conversion or energy efficiency.