Equivalent Uniform Annual Cost Research Articles

Life cycle cost analysis of seismic retrofit policy at the city scale

Many early-developed cities are grappling with aging building environments, characterized by chronic deterioration of structures. The consequent rise in seismic risk and loss has spurred governments to promote relevant disaster mitigation plans. In the process of urban renewal or the retrofit of dilapidated buildings, it is crucial to consider economic feasibility and the impact of policies. To support decision-making, this study aims to develop a framework for evaluating different seismic reinforcement strategies at a city level using a life cycle cost-benefit analysis. The reduction of seismic loss by a certain reinforcement strategy was assessed through the capacity spectrum method, fragility curves, and probabilistic seismic hazard analysis. Construction costs and reinforcement costs were adapted from historical data. The Equivalent Uniform Annual Cost Method was also adopted to analyze the overall life cycle cost of the target buildings based on the chosen reinforcement strategy. The researchers of this study analyzed the private buildings in Taipei City, Taiwan, to demonstrate the proposed method. The priority for reinforcement was determined based on various vulnerability measures of the buildings. Six different reinforcement strategies were compared in the case study. The results revealed that the strategies that can properly exploit soft story reinforcement are more economically attractive in terms of life cycle cost. However, a decline in marginal utility was detected. The results also showed that the proposed method could provide an objective reference for determining the priority of reinforcement plans and effectively mitigate the impact of earthquakes on the community. The findings of this research can assist stakeholders in earthquake disaster preparedness and mitigation.

Economic and environmental assessment of a green pavement recycling solution using foamed asphalt binder based on LCA and LCCA

Cold-in-place recycling with foamed asphalt binders (CIR-F) has been considered as an environmentally sustainable option for asphalt pavement maintenance due to the low mixing temperature and the reuse of up to 100% of existing asphalt materials. However, the quantitative assessment of its economic and environmental performance from a life cycle perspective has rarely been addressed in the literature. To fill in the gap, this study conducted cradle-to-laid life cycle assessment (LCA) and life cycle cost analysis (LCCA) to estimate the annual energy consumption, carbon emissions, and equivalent uniform annual cost (EUAC) of CIR-F and compared it with the traditional mill & fill (M&F). The considered life cycle stages include raw material production, construction, transportation, and work zone traffic management. The heat map visualization technique was employed to explore the influence of service life on the relative environmental and economic advantages of CIR-F. The results show that both economic and environmental impacts of CIR-F were significantly reduced compared to conventional M&F, with 66.45% less cost, 59.62% less energy consumption and 45.73% less carbon emissions. Reducing the service life of CIR-F will reduce, or even completely offset, its benefits over M&F. Assuming a service life of 15 years for conventional M&F, the service life of CIR-F needs to be greater than 8 years to maintain its environmental advantage. The results of this study provide a quantitative assessment of the economic and environmental benefits of CIR-F, providing evidence for its broader application.

Comparative economic analysis of air conditioning system with groundwater source heat pump in general-purpose buildings: A case study for Kayseri

In this study, which aims to reduce energy consumption and dependence on fossil fuels in buildings, the use of an alternative air conditioning system instead of conventional air conditioning systems (CACS), which are widely used in general-purpose public buildings (GPPBs) with high energy consumption, is investigated. A groundwater source heat pump system (GSHPS) was selected as the alternative air conditioning system that exploits an underground water source used in Kayseri province (Turkey). GSHPSs were used both for heating and cooling of a sample GPPB and all costs were determined in detail in the study. In order to compare whether the GSHPS is economical or not, a commonly used CACS, which consisted of a central heating system with natural gas and an air-cooled cooling system was selected. After system components was selected according to the thermal loads of the building, the system costs were determined considering the initial investment cost and the operating costs. Results showed that the proposed GSHPS was more economical than the CACS in terms of initial investment cost and equivalent uniform annual cost by 22.68% and 11.09%, respectively, despite being 3.87% more expensive in terms of total annual operating costs.

Multi-objective optimization of an absorption solar-ground source heat pump considering the environmental and economic performance

ABSTRACT Solar heat pump has attracted more and more attention. This paper aims to improve the performance of an absorption solar-ground source heat pump (ASGSHP) through multi-objective optimization. Firstly, a double-effect absorption heat pump module is developed and a simulation model of the ASGSHP is established on TRNSYS platform. Secondly, considering both the economy and the environmental protection, the equivalent uniform annual cost (EUAC) and the environmental impact load (EIL) are taken as two objective functions. The non-dominated sorting genetic algorithm with elite strategy (NSGA-II) is applied to optimize the environmental and economic performance of the ASGSHP by TRNSYS and MATLAB joint. Pareto front of the multi-objective optimization of the ASGSHP system is obtained. Thirdly, using the TOPSIS decision-making method, the best optimization values for three optimization variables including the solar collector area, the storage tank volume and the setting temperature of the auxiliary heater are obtained. The optimization rate of the environmental impact load and the equivalent uniform annual cost of the optimal point selected by the TOPSIS decision-making method is 10.9% and 3.4%, respectively. The research results can provide the basic data and theoretical guidance for the further development and utilization of the solar-ground source heat pump.

Stochastic Economic Analysis of Investment Projects in Forest Restoration Involving Containerized Tree Seedlings in Brazil

Background: Experts in ecological restoration have discussed the cost reduction to make forest restoration financially feasible. This is very important in developing countries, such as Brazil, and for smallholder farmers; however, economic studies do not usually consider the uncertainties in their analysis. Therefore, this study aimed to analyze, under conditions of uncertainty, how tropical tree seedlings produced in polyethylene bags, polyethylene tubes, and biodegradable containers (Ellepot®) interfere with the costs of implementation and post-planting maintenance investment projects in a deforested tropical seasonal forest area in southern Brazil. Methods: We evaluated total costs, production costs, and equivalent annual uniform costs, and the probability distributions and estimated ranges of stochastic values were adjusted through Monte Carlo method simulation. Furthermore, the seedling survival rate was recorded over 12 months post-planting. Results: The costs with tree seedling acquisition and direct labor were the components that most impacted total costs in the three investment projects. The forest restoration investment project with tree seedlings produced in polyethylene bags was economically unfeasible in relation to other projects. Conclusions: The best economic alternative was observed in the investment project with tree seedlings produced in Ellepot®, which showed a survival rate >80% after one year and the lowest total cost, production cost, and equivalent uniform annual cost.

Sustainable Development with Microsurfacing: A Review

Abstract In recent times, sustainable development has been the primary focus of research and development in the pavement industry. In this respect, microsurfacing was viewed as sustainable pavement preservation and has emerged as a cost-effective pavement maintenance alternative for enhancing performance, increasing service life, and ensuring safety with minimal environmental impact. In this review, the impact of microsurfacing application on the economic, social, and environmental components were explored from the published literature. Studies show that with microsurfacing application, there was a 31 % savings in cost as compared with conventional hot-mix asphalt. Furthermore, a brief economic analysis was carried out, which confirmed microsurfacing as one of the most cost-effective preventative treatment with minimum equivalent uniform annual cost. However, the economic benefits of microsurfacing were dependent upon distress type and intensity, pavement age, climatic conditions, and traffic volume. In addition, the social benefits included enhanced skid resistance, reduced hydroplaning, better riding quality, and pleasing aesthetic appearance. Moreover, the main environmental benefits of microsurfacing, as reported by various researchers, included low energy consumption, reduced greenhouse gas emission, conservation of natural resources, and reduction in tire-pavement noise. Review also reported the strength, weakness, opportunities, and threats of microsurfacing application. Even with certain weakness and probable challenges, application of microsurfacing showed enormous potential for further improvement. Incorporation of recycled or waste materials, compaction prior to opening for traffic, and project-related specifications are some areas for further research. However, certain challenges, like insufficient fund allocation, implementation or performance issues, and production variability, had to be mitigated for smooth and rapid development. Thus, with encouraging results and a promising future, microsurfacing had excelled in both technological and sustainability aspects.

Thermo-economic analysis of heat-driven ejector system for cooling smelting process exhaust gas

This study presents a new solution for cooling the exhaust gas of an aluminum smelting process, thus increasing the efficiency of the Gas Treatment Center (GTC). High-temperature waste gas enters the GTC, where contaminants are removed before release to the atmosphere. After the smelting process, the gas temperature varies between 100 °C (in winter) and 150° (in summer). It should not exceed 135 °C at the GTC inlet to ensure good scrubbing process performance. A heat-driven ejector system is proposed for this purpose. Its main advantage is that it can produce a double effect cooling by utilizing waste heat from the exhaust gas. The peculiar feature of the proposed design is that both the generator and the evaporator of the ejector system are used to produce a cooling effect for the smelter exhaust gas. A simulation model of the proposed system is developed, and a two-step approach is applied to complete the thermo-economic analysis. At the first step, formulated as a thermodynamic evaluation, the total heat transfer area was minimized as a function of the generator temperature difference. In the second step, the optimum value of this parameter is used to design the heat exchangers and the ejector. The results show the existence of an optimum value for the generator temperature difference that minimizes the total heat transfer area. An economic analysis based on evaluating the Equivalent Uniform Annual Cost (EUAC) criterion concludes the investigation. It is shown that the new optimization strategy for an ejector system improves its viability as a potential solution for cooling smelting process exhaust gas. The proposed ejector system can reduce the total heat transfer area and the capital cost up to 34% and 57% compared to a commercially available cooling system.

A novel stochastic optimization model to design concentrated photovoltaic/thermal systems: A case to meet hotel energy demands compared to conventional photovoltaic system

This study offered a novel optimization model to design hybrid solar photovoltaic systems. In addition, the model was able to compare results from conventional photovoltaic panel systems to combined cooling, heating and power systems coupled with concentrated photovoltaic/thermal technology. In the trigeneration system, the concentrated photovoltaic/thermal collector, operating with an absorption chiller and hot water tank stratified, was modeled to supply the energy loads of hotels located in the city of Rio de Janeiro. Monte Carlo simulation considering uncertainty scenarios was applied to model the electric, cooling, and hot water demands, minute by minute, over a year. The optimal size of each system maximized the equivalent uniform annual cost through nonlinear programming, using the Basic Open-source Nonlinear Mixed Integer programming method. The decision variables for the combined cooling, heating and power system were the number of concentrated photovoltaic/thermal collectors and the hot water storage capacity. For the conventional photovoltaic system, the decision variable was the number of photovoltaic panels to be installed. In total, 16 hotels were optimized, showing that the total electrical demands met by the photovoltaic systems vary between 30% and 65%, decreasing as the hotel demands grow. Conversely, the trigeneration system would supply around 26–48% of electrical demands, 40–50% of cooling requirements, in addition to providing 20–45% of hot water for heating.

Avaliação econômico-financeira de sistemas de manejo de águas residuárias de origem doméstica em empreendimentos habitacionais

O propósito deste estudo é avaliar a viabilidade econômico-financeira dos sistemas de manejo de águas residuárias de origem doméstica em empreendimentos habitacionais de interesse social. Trata-se de dois sistemas compartimentados anaeróbio/aeróbio/anóxica vertical para remoção de carbono e nitrogênio. A análise econômico-financeira do projeto piloto dos sistemas compartimentados foi composta pelo Valor Presente de Custo, Custo Anual Uniforme Equivalente, Entradas de caixa de Breakeven, Análise de sensibilidade e Simulação de Monte Carlo. O resultado da análise tradicional considerou o melhor resultado as premissas “Com Reuso e Sem Investimento Inicial”. De acordo com as entradas de caixa de Breakeven, quanto maior for o custo de capital, maior a entrada de caixa requerida para que o projeto seja viável. Para a análise de sensibilidade, o custo do projeto a valor presente diminui à medida que o custo do capital aumenta, reduzindo, assim, a inviabilidade. No Custo Anual Uniforme Equivalente, nas premissas “sem investimento inicial” e “com investimento inicial” quanto maior o custo de capital, menor e maior o CAUE, respectivamente. Nas simulações de Monte Carlo realizadas, as análises baseadas na interpretação de indicadores tradicionais foram extremamente otimistas, contudo pouco representam a realidade, tanto que a probabilidade de ocorrência é menor que 1%.

Simulation and Performance Evaluation of a Parabolic Solar Collector and a Boiler for Brine Reductio

Salt management technique in irrigated agriculture is becoming more important at the San Joaquin Valley of California as well as a number of other areas worldwide. Concentration and evaporation systems using solar energy are being developed in California for salt separation and recovery from drainage water. A model for the parabolic solar collector yielded accurate predictions relative to experimental data for fluid temperature changes and peak fluid temperatures. The peak temperature measured at 72°C was accurate when compared to the calculated results. The evaporation rate of the boiler was 82 kg/h from the model prediction and 76 kg/h from experimental measurements. The predicted efficiencies of the parabolic solar collector and the boiler were approximately 64% during the daytime and 70%, respectively. The cost per kg of dry salts based on net present worth (NPW) for the boiler prototype was $0.90 and $1.34 based on equivalent uniform annual cost (EUAC) with respect to 1 year, respectively, and the costs decreased as the boiler capacity increased.

DEVELOPMENT OF OVERWEIGHT PERMIT FEE USING MECHANISTIC-EMPIRICAL PAVEMENT DESIGN AND LIFE-CYCLE COST ANALYSIS

The study aims to determine rational overweight permit fee using Mechanistic-Empirical (M-E) pavement design and Life-Cycle Cost Analysis (LCCA). The state-of-art pavement design software, Pavement-ME, was utilized to develop Load Equivalency Factors (LEFs) and estimate pavement service life under various traffic loading conditions. LCCA was conducted to calculate Marginal Pavement Damage Cost (MPDC) in terms of Equivalent Uniform Annual Cost (EUAC) considering variations in maintenance strategies, analysis periods, and discount rates. A methodology framework was established to calculate distance based, weight based, weight and distance based, and flat permit fee for overweight trucks. With the local data obtained in New Jersey (United States), example permit fees were determined for the major and local road network with the thick and thin asphalt pavement structure, respectively. It was found that the truck-induced damage cost varied significantly between thin and thick asphalt pavements considering different failure mechanisms in fatigue cracking and rutting. In general, overweight permit fee may not be fair to overweight trucks at different vehicle classifications if only the total overweight tonnage is regulated in the permit fee structure.

Critical Assessment of the Long-Term Performance and Cost-Effectiveness of a New Pavement Preservation Method: Micromilling and Thin Overlay

The Georgia Department of Transportation (DOT) has developed and implemented a new pavement preservation method that uses micromilling in conjunction with a thin overlay for cost-effective replacement of a deteriorated, thin, open-graded surface layer (¾ to 1¼ in.) without removing the sound underlying layer. The new method was first implemented in 2007 on a 15.3 mi section on I-75 near Perry, Georgia, and resulted in significant savings. In considering whether to adopt the new method as standard practice in pavement preservation, it is essential to evaluate the method’s actual, long-term performance. This is the first paper to report the actual, long-term performance of the new method. The study used 8 years of pavement condition data collected by the Georgia DOT and sensing data collected by Georgia Institute of Technology. Based on the data, the pavement on I-75 is still in good condition after 8 years (with 6% raveling in 2015). Based on the current condition and the Georgia DOT’s past experience with open-graded surface mixes, the Georgia DOT anticipates an additional 2 to 3 years of service for the I-75 project. This provides a service interval of 10 to 11 years, which is comparable to that of Georgia’s conventional pavement rehabilitative strategy for open-graded surfaced Interstate pavements, which typically ranges from 10 to 12 years. The equivalent uniform annual cost of the new method is $11,200 per lane-mile per year, which is 11% lower than the $12,600 per lane-mile for the conventional rehabilitation method computed on a 12-year service interval. This information can assist transportation agencies in making decisions about whether to apply the new pavement preservation treatment.

복합이자율과 민감도분석에 기반한 LCC 기법에 의한 LNG 연료추진 선박 경제성 평가 사례 연구

The purpose of this study is to compare the economics between a diesel propulsion vessel and a LNG fuel propulsion vessel through the analysis of the present value using the LCC(Life Cycle Cost) method. This study is also to judge the economics for long-term operation of a LNG fuel propulsion vessel as a result of analysis about the equivalent uniform annual cost. In particular, LCC method was strengthened by sensitivity analysis based on combined interest rate which is considering discount rate and inflation rate simultaneously.

Economic evaluation for cooling and ventilation of medicine storage warehouses utilizing wind catchers

Renewable energy consumption has become a dominant issue in many countries because of environmental crisis, pollution, climate change and increased costs of non-renewable sources like fossil fuels. Because of global warming and energy prices designers are refocusing on the low carbon credentials of new equivalents. In this context, the main target of the proposed study is to present a new innovative method of cooling the non-refrigerator medicine storage warehouses in order to minimize energy costs and environmental hazards for the city of Yazd in Iran. For this purpose, warehouses with absorption chillers, underground warehouses, and underground warehouses including wind catchers have been analyzed. Then, the equivalent uniform annual cost (EUAC) method was applied for evaluating the costs of the three alternative systems. The results of this study show that the use of wind catcher is far more economical than the absorption chiller cooling system. Moreover, it is concluded that the construction of an underground warehouse with a wind catcher is the most economical option for the storage of medicines than the other warehouses in this case study.

Two Other Important Indicators for the Assessment of Eco Dwelling

The authors of this paper propose a practical way to assess the environmental and financial costs of the performance of a real engineering activity for the case of a dwelling/building. This estimation is based on two indicators: Energy consumption during the Life Cycle of the building, EcLC and Equivalent Uniform Annual Cost, EUAC, related in various ways within the Building Life Cycle. The first indicator is determined by the Material Selection Method (CES Eco-Selector Software). While second indicator, EUAC, is determined by means of the Method of Life Cycle Cost. Consideration of these indicators from the conceptual phase of the object (dwelling), minimizes the costs of implementation and usage of the dwelling while respecting the principles of environment sustainable development. A dwelling as a product may have an environmental label, containing these two environmental and financial indicators, determined to take into account the entire life cycle. Results confirm the validity of some of the most innovative technologies currently applied in buildings and support our proposal on their energy label change.

An Economic Assessment of Burner Replacement in Various Industries of Iran

Applying the new efficient burner technology in various industries is a primary subject of interest for reducing the fossil fuel energy consumption as well as reducing air and noise pollution. Replacing the old and low-efficiency burners with the new efficient ones seems to have noticeable saving potential in many industrial sections of Iran. In this article, the replacing of current running low efficiency burners in 27 studied industries with the new high-efficiency burners was investigated in four industrial groups. The Equivalent Uniform Annual Cost (EUAC), which is a comprehensive economic evaluation method for two competing industrial projects, was used for this assessment. The estimation of need for new efficient burners (based on collected statistical data) showed that there was about 570,000 burners presently running in the 27 studied industries in four industrial groups from which 66% (about 380,000 burners) couuld be economically replaced with the high-efficiency burners. Furthermore, economic evaluation showed that in most of the non-metal mineral industries such as cement, lime, and brick production, and some metal industries such as casting, replacing the old burners with the high-efficiency ones was very profitable.

Cost-Benefit Analysis of Thin Surface Treatments in Pavement Treatment Strategies and Cycle Maintenance

AbstractIn this paper, a cost-benefit analysis is reported for selecting the most economical alternative among various pavement preservation choices using life-cycle cost analysis analytical technology. The impact of pavement conditions on the performance of the specific treatment was investigated in terms of pavement performance curves, which were developed for the treatments under varying pavement condition levels at each traffic network based on Pennsylvania Department of Transportation overall pavement index (OPI) data. A relationship between pavement life extension and pavement condition prior to the treatment was established. Finally, life-cycle cost analysis was conducted to quantify the impact of the pavement condition on the performance of the preservative treatments in terms of the benefit-to-cost ratio and net equivalent uniform annual cost. There is an optimum pavement condition and associated age (or a range of conditions or ages) in which the benefit-to-cost ratio that is associated with a t...

Stochastic Life-Cycle Cost Analysis for Pavement Preservation Treatments

The use of life-cycle cost analysis (LCCA) as a decision-making tool in pavement design and the analysis of competing alternatives is recommended by FHWA. However, dependence on deterministic LCCA raises issues about the accuracy of input information because of the degree of construction price volatility found in the underlying commodities used in pavements. Stochastic LCCA has been shown to produce superior results when used at the new pavement design or network level and is suggested for transportation use by FHWA. However, no project-level tools exist to facilitate use of a stochastic approach to evaluate pavement preservation treatment. This paper proposes a practical stochastic LCCA model on the basis of equivalent uniform annual cost, specifically to compare pavement preservation treatment alternatives. The paper explores statistical LCCA techniques that expose inherent uncertainties to identify and quantify the risk of commodity price volatility. The proposed methodology enhances a pavement engineer's ability to address budget issues, mitigate risk, and justify pavement preservation treatment decisions. Underlying commodity price volatility in pavement treatment costs can be modeled effectively with stochastic LCCA.

Criteria for Fleet Management

This paper presents a decision model developed to identify the optimal asset life for six equipment classes, including three on road and three off road. This model was developed as an element of a comprehensive study to identify a methodology to evaluate aging (or depreciation), disposal points, and overall utilization. The asset life optimization model discussed in this paper is a core result of that study and presents the opportunity to reduce overall cost, improve the age of the fleet and its readiness to serve the public, and improve overall utilization. This paper examines salvage values and identifies trend models for market value decline on the basis of historical records. With the use of internal cost information, the model identified trends in cost of operation and use as equipment aged. This information was integrated into an optimal economic life model on the basis of equivalent uniform annual cost to identify the optimal disposal point for the six classes. The analytical models developed in the study provide a foundation for long-term analysis of fleet size and the cost-effectiveness of disposal points.

Life-Cycle Cost-Based Pavement Preservation Treatment Design

Classic engineering economic theory was developed to furnish the analyst with a tool to compare alternatives on the basis of life-cycle cost (LCC). However, tools used to apply theory to transportation focus on new construction projects with relatively long service lives. These tools do not accurately model the economic aspects of short-lived alternatives such as those that pavement managers must evaluate when seeking the most cost-effective pavement preservation treatment. The field of pavement preservation seeks to “keep good roads good,” and hence pavement preservation treatments are applied to extend the functional service life of the underlying pavement. No significant research has been done to quantify the actual service lives of the pavement preservation treatments themselves nor has a model been furnished to analyze their LCCs. The paper addresses those two gaps in the pavement economics body of knowledge by proposing a methodology for using field test data to quantify the service lives of pavement preservation treatments for both asphalt and concrete pavements. In addition, the paper concludes that an LCC model based on equivalent uniform annual cost, rather than net present value, specifically addresses the relatively short-term nature of pavement preservation treatments and allows the engineer to better relate treatment LCC output to annual maintenance budgets.