Conversion Cost Research Articles

Lite-Sparse Hierarchical Partial Power Processing for Second-Use Battery Energy Storage Systems

The explosive growth of electric vehicles (EVs) is leading to a surge in retired EV batteries, which are typically recycled despite having nearly 80% available capacity. Repurposing automotive batteries for second-use battery energy storage systems (2-BESS) has both economical and environmental benefits. The challenge with second-use batteries is the heterogeneity in their state of health. This paper introduces a new strategy to optimize 2-BESS performance despite the heterogeneity of individual batteries while reducing the cost of power conversion. In this paper, the statistical distribution of the power heterogeneity in the supply of batteries is used to optimize the choice of power converters and design the power flow within the battery energy storage system (BESS) to optimize power capability. By leveraging a new lite-sparse hierarchical partial power processing (LS-HiPPP) approach, we study how a hierarchy in partial power processing (PPP) partitions power converters to significantly reduce converter ratings, process less power to achieve high system efficiency with lower cost (lower efficiency) converters, and take advantage of economies of scale by requiring only a minimal number of sets of identical converters. Our results demonstrate that LS-HiPPP architectures offer the best tradeoff between battery utilization and converter cost and have higher system efficiency than conventional partial power processing (C-PPP) in all cases.

A Flyback Converter With Novel Active Dissipative Snubber

The active clamp flyback converters (ACF) can provide features of high power density and high power efficiency. However, ACF is usually applied to in the applications of medium-to-high power range. For a low power application, the ACF may not be a cost-efficient choice. The flyback converter with a lossless snubber can provide high efficiency for low-power application, but it needs an additional inductor and generates more electromagnetic interference (EMI) emissions. The circuit designers also consider the balance between conversion efficiency, size, and cost. Based on the reasons above, the flyback converter with dissipative RCD snubber is still popular in the applications of low-to-medium power range. When the dissipative snubber is adopted to reduce EMI in the power converters, it increases the loss and hence reduces the efficiency. In this paper, a new concept, called active dissipative snubber, is proposed to suppress the resonance in the discontinuous conduction mode (DCM). In the proposed active dissipative snubber, the digital controller activates the dissipative snubber only when the EMI noise is occurring, then disabled after the noise is decayed or disappears. Digital logic makes the passive snubber smart, which can selectively absorb the EMI noise. Since the proposed snubber is not connected to the main circuit all the time, it can provide lower power loss, but still performs better EMI emissions and maintains conversion efficiency.

Theoretical prediction and design for chalcogenide-quantum-dot/TiO2 heterojunctions for solar cell applications.

Quantum dot sensitized solar cells have attracted much attention due to their high efficiency of photoelectric conversion and low manufacturing cost. In this study, a series of heterojunction structures with cubic (MA)4 chalcogenide quantum dots adsorbing on the (001) surface of TiO2 were investigated, in order to explore new quantum dot sensitizers for solar cell applications. Our study revealed that sulfide and selenide quantum dots are more suitable for solar energy harvesting, compared to their oxide counterparts, due to their smaller ionization potentials and smaller HOMO-LUMO (highest occupied molecular orbital-lowest unoccupied molecular orbital) gaps, but in general exhibit weaker adsorption on TiO2. M4A3B and M4A2B2 quantum dots were designed in combination with the advantage of higher adsorption stability and photoelectric conversion capability. Our theoretical predictions for the structurally precise chalcogenide systems suggest a possible direction for the design of quantum-dot sensitized solar cells.

Analysis on Pinduoduo Business Model and Future Development Strategy based on Sinking Market

This paper analyses Pinduoduo's success and make suggestions to help it further improve its business model for the long term and provide a reference experience of similar e-commerce companies by using moat theory. In the long run, the competitiveness of its competitors in the same industry cannot be underestimated. In the current situation, Pinduoduo's moat is weak in terms of intangible assets and user conversion costs due to the poor quality of most of the products on its platform and that its primary users are price-sensitive users. In this context, the authors give following suggestions for its future development: 1. Highlight brand characteristics and ensure product quality 2. Create differentiated competitive advantages 3. Improve supply chain structure and back-end service system 4. Refined operation of existing users and stop blindly expand users.

Combining Multivariate Electrospinning with Surface MOF Functionalization to Construct Tunable Active Sites toward Trifunctional Electrocatalysis.

The development of high-performance multifunctional electrocatalysts operating in the same electrolyte is key to reduce the material and process costs of renewable energy conversion and storage devices. Herein, the fabrication of freestanding integral electrodes by combining multivariate electrospinning with surface metal organic framework functionalization to arrest pyrolytic emissions from fiber interior is reported, resulting in the expression of rich active sites with controlled composition, for example, the tunable Co-P coordination. The as-fabricated electrode of CoP@CF-900, when used as both the cathode and anode for overall water splitting, is able to deliver 200mA cm-2 at a cell voltage of 1.89V, significantly outshining the Pt/C‖RuO2 couple; when used as the air cathode for a zinc-air battery, is able to operate more than 150 h at 10mA cm-2 with a nearly constant round-trip energy efficiency of ≈60%, also outperforming the Pt/C+RuO2 benchmark. The activity and kinetics origin of the superb multi-functionality is further elucidated through extensive electroanalytical, post-mortem, and operando characterizations, which underscore the construction of robust integral electrodes through synergistic structure and composition engineering.

Spatial optimization for urban green space (UGS) planning support using a heuristic approach

Urban green space (UGS) has rich ecological and social benefits, and is closely related to the well-being of residents. Its spatial equity is a major concern for both residents and planners. However, effective decision-making support tools for UGS planning are still lacking. This study therefore proposes a UGS spatial optimization method that takes spatial equity and conversion cost into account to optimize the UGS layout in Xuzhou, China. The essence of the purposed optimization method is to constantly adjust the conversion probability of alternative land parcels into UGS to obtain a UGS layout that minimizes the overall conversion cost under the constraints of per capita UGS and spatial equity requirements. It is suggested that UGS spatial configuration is highly complex and that basic spatial units, population distribution, spatial equity, and the costs of conversion all need to be considered when planning UGS, which moreover needs to be optimized based on various spatial analysis. UGS spatial optimization should be integrated with planning regulated indicators such as per capita UGS and spatial equity, the implementation of which should be feasible based on the current UGS layout and land use situation. The proposed UGS spatial optimization method can generate optimized UGS layouts that meet controlling demands of planning, lowering UGS construction costs while improving spatial utility. It can provide decision support for UGS planning and has broad application prospect.

USE OF LOW POTENTIAL ENERGY FOR ELECTRIC AND THERMAL ENERGY PRODUCTION

This article presents new directions for the search for alternative energy sources that can be extracted from the environment, have unlimited reserves, low cost of conversion into other types of energy, do not use fossil fuels, are autonomous, environmentally friendly, do not depend on meteorological conditions and the time of year, do not require long lines for power transmission. Objectives: Rational use of fuel and energy resources is today one of the global world problems, the successful solution of which, apparently, will be of decisive importance not only for the further development of the world community, but also for the preservation of its habitat

Optimization of regional distributed energy system under discrete demand distribution

This study break through the idealized demand-side distribution and build an optimization model of regional distributed energy systems under discrete conditions. Aiming at minimizing the system comprehensive cost, which includes the annual conversion cost of the initial investment and the annual operation and maintenance cost, the optimization model can determine the number, site, capacity of the energy station and the optimal pipe network layout path from the energy station to the load center, and make a comparative analysis of the annual costs in different situations. The main impact of the energy station site is the cost difference caused by the pipe network layout.

Factors Affecting the Adoption of Financial Reporting Standards by Micro, Small and Medium Enterprises in Tanzania: The Case of Mbeya City Council

Different studies have revealed that the majority of the micro, small and medium enterprises (MSMEs) in Tanzania do not use basic accounting principles and practices which are consistent with financial reporting standards in managing business though Tanzania adopted International Financial Reporting Standards for small and medium enterprises (IFRS for SMEs) in 2009 and issued financial reporting standard for Micro entities in 2018. This shows that the level of adoption and applicability of the standards is very low. Therefore, this study was carried out to assess factors that affect the adoption of financial reporting standards by MSMEs in Tanzania. The study was conducted in Mbeya City Council where primary data was collected from a sample size of 245 respondents via a Likert scale questionnaire. The descripto-explanatory research design was employed where the results were quantitatively analysed through descriptive statistics and chi-square (x2) model hypothesis testing. The results show that non-adoption of the standards was the result of inadequate knowledge by MSMEs, lack of awareness by most MSMEs on the existence of the standards, high perceived cost of conversion and implementation, weak legal and regulatory enforcement strategy, low level of technology applicability by SMEs and complexity of the standards as it needs a well-trained accountant to implement. The study recommends the government to come up with the implementation strategy that will first ensure that a large number of MSMEs is well trained on financial reporting standards because the decision to adopt or not to adopt largely depend on the adequacy of knowledge.

Performance benchmarking of power-to-gas plants using Composite Indicators

Driven by the need for decarbonizing energy carriers across sectors, and the increasing availability of low-cost renewable electricity generation future energy systems will see a rise of power-to-gas technology. For example, hydrogen and its derivates can make enable the usage of carbon-neutral electricity for hard-to abate industry sectors and serve as long-term seasonal storage. Given recent drafts of ambitious political hydrogen strategies around the world, the question arises which power-to-gas configurations provide the highest value for money from a power system perspective. This work provides a flexible framework to compare the performance of current power-to-gas sites all over the world. Power-to-gas technologies are assessed with a benchmarking framework based on Composite Indicators to compare the system value of existing conversion technologies, plant sizes, cost structures, and configurations. Our analysis confirms recent research that suggests that plant performance is higher for larger projects and improves as projects move from research stage over pilot stage to commercial stage. Our findings inform policy makers and electricity system planners who aim to identify the economically and technically most promising solutions for investment.

The case for fluoride-ion batteries

<h2>Summary</h2> Fluoride-ion batteries (FIBs) have recently emerged as a candidate for the next generation of electrochemical energy storage technologies. On paper, FIBs have the potential to match or even surpass lithium-metal chemistries in terms of energy density, while further eliminating the dependence on strained resources, such as lithium and cobalt. Research into FIBs has accelerated since its inception in 2011. In this perspective, we examine the case for fluoride-ion batteries, considering electrode and electrolytes from the literature and beyond, to outline the potential pathways to a competitive energy storage technology. We present the most promising, feasible conversion-type cathode and anode materials in terms of capacity, electrode potential, volume change, crystal structure, and cost/abundance. The capabilities of current and future fluoride intercalation electrodes are also examined. Using a subset of these materials, we conduct a techno-economic analysis comparing the energy density and cost of conversion and intercalation-type FIBs with state-of-the-art lithium-ion batteries and high-energy-density lithium-metal-based chemistries. This investigation highlights the potential commercial value of conversion-type, liquid-cell FIB, with energy densities as high as 588 Whkg⁻¹ (1,393 WhL⁻¹) and costs as low as 20 US$ kWh⁻¹ at the stack level. This perspective highlights the major obstacles hindering the development of FIBs, drawing relevant lessons from the lithium-ion literature. In order to practically advance FIBs into a viable technology, further research must be focused on safe liquid fluoride electrolytes and solid electrolyte interphase formation; mechanistic study and theoretical modeling of electrode materials; and stable non-active battery components and reference electrodes. We conclude by prescribing several critical research fronts in these areas.

Fishmeal replacement by periphyton reduces the fish in fish out ratio and alimentation cost in gilthead sea bream Sparus aurata

Aquaculture threatens natural resources by fishing down the sea to supply fishmeal. Alternative protein sources in aquafeeds can provide a solution, particularly those that are waste from other operations and thereby reduce feed production costs. Toward this goal, we examined the waste biomass of marine periphyton from biofilters of an integrated multi-trophic aquaculture (IMTA) system as a replacement for fishmeal in diets of gilthead seabream (Sparus aurata). Four isoproteic (41%) and isolipidic (16.7%) aquafeeds were formulated with increased content of periphyton and a corresponding decrease in fishmeal from 20 to 15, 10, or 0%. The growth and biochemical content of seabream fingerlings (initial body weight 10 g) were examined over 132 days. Replacing 50% of fishmeal by waste periphyton improved feed conversion ratio (1.2 vs. 1.35 in the control diet) without harming fish growth. The complete replacement of fishmeal with periphyton resulted in 15% slower growth but significantly higher protein content in the fish flesh (59 vs. 52% in the control diet). Halving fishmeal content reduced feed cost by US$ 0.13 kg−1 feed and saved 30% in the cost of conversion of feed to fish biomass (US$ 0.58 kg−1 produced fish vs. $0.83 in the control diet). Finally, the total replacement of fishmeal by waste periphyton in the diet reduced the fish in—fish out ratio to below 1 (0.5–0.9) as compared to 1.36 in the control diet. Replacing fishmeal with on-farm produced periphyton minimizes aquaculture footprint through the removal of excess nutrients in effluents and the use of waste biomass to reduce the ‘fish in’ content in aquafeeds and fish production costs. The present study demonstrates the great practical potential of this dual use of marine periphyton in enhancing the circular economy concept in sustainable fish production.

CO2 capture and activation with a plasma-sorbent system

Non-thermal plasma-induced one-step desorption of splitting of CO2 has been investigated in this research for carbon capture and utilization. An experimental study was conducted in a plasma-sorbent system that consists of a coaxial DBD reactor packed with hydrotalcite pellets. Operation parameters including discharge power and carrier gas flow rate were varied to explore their effect on the desorption of CO2 from the sorbent and conversion to CO. Results showed that the discharge power plays the dominant role in the desorption process. Faster desorption was achieved with increasing power but at a cost of CO2 conversion. Although the carrier gas flow rate does not have a significant effect on the desorption, higher conversion was achieved with a higher flow rate due to the dilution effect. The maximum single pass conversion of CO2 achieved was 67.44%. Based on the feature of this technology, periodic operation of multiple reactors including reactors in parallel and in series are discussed for continuous CO2 capture and its full conversion.

Modified thin film perovskite solar cell for high conversion efficiency

Recently, perovskite materials opened up a door for the researchers due to their flexibility, photonic conversion efficiency and cost effectiveness. In this work, we study the performances of various active materials categorized as organic, inorganic and organic-inorganic hybrid materials and compare their optical performances to select the efficient material with the help of finite difference time domain analysis (FDTD) and Device solutions provided in Lumerical simulator. We choose conventional active materials like poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM) as organic active material, cesium lead iodide (CsPbI3) as inorganic active material, and both formamidinium lead iodide (FAPbI3) and methylammonium lead iodide (CH3NH3PbI3 or MAPbI3) as organic-inorganic hybrid active material. Finally, we propose a simple modified thin film perovskite solar cell structure considering previously selected most efficient active material and we achieve maximum photonic conversion efficiency 17.4% having short circuit current density 26.1 mA/cm2 and open circuit voltage 0.78 V with a fill factor of 86%.

Nutritional and economic benefits of using DDGS (distiller’ dried grains soluble) as feed ingredient in common carp semi-intensive pond culture

A survey was conducted to evaluate the suitability and profitability of corn DDGS (distiller’ dried grains soluble) as a protein source in feed for common carp (Cyprinus carpio L.) in semi-intensive pond production. Six ponds of 0.17 ha were stocked with 70 pc 2+ and 1050 pc 1+ old carp with average weight 362 ± 10 g and 45 ± 1 g, respectively, and fed with two types of feed in triplicates. Fish were kept on natural pond food supplemented periodically with wheat grains in the first part of feeding season in order to minimize nutrition costs. When the sampling harvest result indicated that growth rates were slowing down wheat was replaced with formulated feeds (control and experimental diets) as external food source till end of experiment. The experimental feed contained 40 % DDGS substituting the plant ingredients of the control feed. Growth, nutrient utilization, health, flesh quality of the fish was compared at the end of rearing season and finally the economic performance of the diets was investigated. Significantly better performance of experimental group was found in most of the production parameters (final weight, weight gain, specific growth rate) at juvenile age and in feed conversion rate (1.56 vs 1.78 g/g), protein efficiency ratio (2.32 vs 2.08 g/g), gross yield (3520 vs 3020 kg/ha) of the ponds. Economic advantage of high DDGS inclusion in carp feeds was demonstrated by significantly improved per-hectare profit and benefit-cost ratio. These are attributed to higher yields, better feed conversion and lower cost of novel feed formulation. Health and flesh quality of the fish were not affected by the diet composition. It was concluded that combining the use DDGS-based compound feeds with maximal exploitation of pond food results in better production, nutrient utilisation and economic performance than traditional cereal-based semi-intensive carp farming.

Plasma chemical conversion of methane by pulsed electron beams and non-self-sustained discharges

Investigations of methane conversion in atmospheric-pressure mixtures of various composition and temperature, irradiated by pulsed nanosecond electron beams and non-self-sustained discharges initiated by electron beams, were carried out. It was shown that during direct conversion at room temperature, the energy cost of the conversion of one CH4 molecule (5.6 eV molecule−1) was commensurate with that obtained in the experiments with the use of continuous electron beam. The main products of direct conversion were hydrogen and ethylene. If a small amount of oxygen was present in the mixture, methanol was added to the conversion products, which in turn decomposed into CO, CO2 and H2O. The results of numerical simulations and experiments were basically the same. The use of a non-self-sustained discharge increased the degree of direct conversion of methane, but the energy cost of conversion also increased. The main products of carbon dioxide conversion of CH4 (dry reforming) under the action of pulsed electron beam at room temperature were CO, H2, C2H6, and carbon. Energy cost of conversion (12 eV molecule−1) was about two times higher than in the case of direct conversion of methane. However, the use of pulsed electron beam for dry reforming turned out to be energetically more efficient than the use of the most types of discharges. The main products of CH4 oxidative conversion by pulsed electron beam were H2, C2H6, and C2H4. At room temperature, the energy cost of methane conversion without a catalyst was 9 eV molecule−1, whereas the use of Ni catalyst resulted in a seven-fold increase, and the use of NaOH/CaO one—in a 14-fold increase in the conversion efficiency compared to irradiation without a catalyst. When the temperature of the catalysts rised to 623 K, the conversion efficiency increased by another four times. The processes in electron-beam plasma that provide the implementation of the main mechanisms of methane conversion are also discussed in the paper.

코로나 상황에서 비대면 문화예술 서비스에 대한 소비자 인식 분석 연구: 노원문화재단 서비스에 대한 지역민의 인식을 중심으로

The purpose of this study is to analyze consumer perception of non- face-to-face cultural and art-based services during the COVID-19 pandemic and suggest policy implications. This study examined the barriers to transition, relationship between awareness of COVID-19 and intention of transition, and moderating effect of cultural and art-related intentions of enjoyment in these relationships. To this end, 400 samples were collected by conducting a questionnaire-based survey on the residents of Nowon-gu, Seoul and the research hypothesis was verified using the data. First, it was found that the relational cost of the barrier to conversion was the most important factor in lowering the intention of conversion, and the intention of conversion of the financial and procedural cost of conversion, and recognition of the COVID-19 problem and constraint did not lower the intention of conversion. Second, it was found that intention of cultural and artistic enjoyment has a moderating effect in relation to relational cost of conversion, recognition of the COVID-19 problem, awareness of involvement and intention of conversion. This study is meaningful in that it is necessary to consider the factors that impact the intention of cultural and artistic enjoyment that explain the context of the study when the barrier to transition and the theory of public context are to predict the intention to adopt a cultural and art-based non-face-to-face service. In addition, this study provides various implications for strategies to increase the efficiency of non-face-to-face services.

Assessing Marginal Land Availability Based on Land Use Change Information in the Contiguous United States.

Utilization of marginal land for growing dedicated bioenergy crops for second-generation biofuels is appealing to avoid conflicts with food production. This study develops a novel framework to quantify marginal land for the Contiguous United States (CONUS) based on a history of satellite-observed land use change (LUC) over the 2008-2015 period. Frequent LUC between crop and noncrop is assumed to be an indicator of economically marginal land; this land is also likely to have a lower opportunity cost of conversion from food crop to bioenergy crop production. We first present an approach to identify cropland in transition using the time series of Cropland Data Layer (CDL) land cover product and determine the amount of land that can be considered marginal with a high degree of confidence vs with uncertainty across the CONUS. We find that the biophysical characteristics of this land and its productivity and environmental vulnerability vary across the land and lie in between that of permanent cropland and permanent natural vegetation/bare areas; this land also has relatively low intrinsic value and agricultural profit but a high financial burden and economic risk. We find that the total area of marginal land with confidence vs with uncertainty is 10.2 and 58.4 million hectares, respectively, and mainly located along the 100th meridian. Only a portion of this marginal land (1.4-2.2 million hectares with confidence and 14.8-19.4 million hectares with uncertainty) is in the rainfed region and not in crop production and, thus, suitable for producing energy crops without diverting land from food crops in 2016. These estimates are much smaller than the estimates obtained by previous studies, which consider all biophysically low-quality land to be marginal without considering economical marginality. The estimate of marginal land for bioenergy crops obtained in this study is an indicator of the availability of economically marginal land that is suitable for bioenergy crop production; whether this land is actually converted to bioenergy crops will depend on the market conditions. We note the inability to conduct field-level validation of cropland in transition and leave it to future advances in technology to ground-truth land use change and its relationship to economically marginal land.

How to Make Off-Grid Solar Electric Cooking Cheaper Than Wood-Based Cooking

Low-income sub-Saharan Africa (SSA) households rely on wood for cooking for the simple reason that it is the lowest cost cooking fuel. Thus, full attainment of Sustainable Development Goal 7 (SDG7) requires developing clean cooking technologies that are cheaper than wood cooking. This study provides a comparative marginal levelized cost of energy (MLCOE) analysis for wood cooking vs. innovative solar electric cooking technologies. The two key off-grid solar technologies evaluated are: (1) direct-use DC solar (DDS) electricity for cooking applications, and (2) high-cycle-life lithium titanate (LTO) batteries. MLCOE is reported in USD/kWh for energy delivered to cooked food. A low median MLCOE of USD 0.125/kWh is attained using DDS electricity which is output directly by a solar panel with little or no intervening electricity storage and few electricity conversion and control costs. DDS solar panel output has variable voltage and current that is managed by a specialized DDS cooker. LTO battery-regulated electricity has a median MLCOE of USD 0.24/kWh which declines to USD 0.16/kWh with electric pressure cooker use. The distributions of MLCOE for wood-based, DDS-electric, and LTO-electric cooking strongly overlap. The MLCOE cost model suggests specific means for modifying input costs, component lifetime, and system efficiency to improve solar MLCOE further relative to wood MLCOE.

Standards Harmonization and Asymmetric Compliance Technology

Purpose - The purpose of this paper is to examine the welfare effects of standards harmonization between technologically asymmetric countries, and to determine optimal harmonization strategies for a country with mid-level technological advancement. Design/methodology - Following Salop’s circular city model (Salop, 1979), this study constructs a simple, horizontally-differentiated oligopoly model in which three firms and three countries exist. Each country adopts different compatibility standards and each firm incurs conversion costs for foreign market access due to differences in standards. The conversion costs are related to technology; standards harmonization removes these costs between participating countries. The paper considers three cases: i) no harmonization; ii) harmonization with the more technologically-advanced country and iii) harmonization with the less technologically-advanced country. Findings - The paper first considers a scenario in which all three firms occupy some share of the market in each country. It shows that standards harmonization with both the technologically more-or less-advanced country always increases consumer surplus and social welfare. In addition, the producer surplus will increase if the harmonization partner has a higher technology level, whereas it may decrease if the partner has a lower technology level. It also shows that if most domestic export goods are in sectors with conversion costs above a certain level, harmonizing standards with a technologically more-advanced country should be prioritized. Such strategies, moreover, should be emphasized when there exists a large technology gap among countries. Lastly, the paper considers another scenario, in which harmonization leads to the foreclosure of the non-member firm from the member countries’ markets. It shows that harmonization improves the social welfare of a mid-level technology country regardless of its partner’s technology. It also shows that the country should prioritize harmonization with the technologically less-advanced country. Originality/value - Though some of the existing studies consider the welfare effects of harmonization, their main assumption is that firms have the same conversion technology. Since complying with standards often requires substantial technological advancement and technical expertise, harmonization of compatibility standards between countries with gaps in technological ability carries different implications. This paper investigates the welfare effects of this harmonization and determines an optimal harmonization strategy while considering technological asymmetry among countries in standards compliance.