Life Cycle Cost Basis Research Articles

Energy life cycle cost analysis of various solar water heating systems under Middle East and North Africa region

Middle East and North Africa region's abundant solar and wind resources provide a valuable opportunity to diversify energy production and offer a high potential for renewable energies. Thus, the solar water heating systems offer a key element in the deployment of renewable energy throughout the region. To this end, a model was developed and validated to evaluate the performance of these systems with different collectors. Then, an exhaustive energetic, exergetic, environmental and economic analysis of all the region's countries was carried out on the basis of the required meteorological data. Regarding the results for the entire region, the maximum solar fraction values attain 60 % and 83 % for the flat plate and evacuated tube systems, respectively. Under current economic assumptions, propane water heating is cheaper on a life cycle cost basis than electric and diesel heating throughout North Africa. Also, the use of auxiliary electric generators is suitable for all countries in the Middle East region except for Manama-Jordan, Abu Dhabi-UAE and Ankara-Turkey.

Renewable energy transport via hydrogen pipelines and HVDC transmission lines

The majority penetration of Variable Renewable Energy (VRE) will challenge the stability of electrical transmission grids due to unpredictable peaks and troughs of VRE generation. With renewable generation located further from high demand urban cores, there will be a need to develop new transmission pathways to deliver the power. This paper compares the transport and storage of VRE through a hydrogen pipeline to the transport of VRE through a High Voltage Direct Current (HVDC) transmission line. The analysis found a hydrogen pipeline can offer a cost-competitive method for VRE transmission compared to a HVDC transmission line on a life-cycle cost basis normalized by energy flows for distances at 1000 miles with 2030 technology. This finding has implications for policy makers, project developers, and system operators for the future development of transmission infrastructure projects given the additionality which hydrogen pipelines can provide in terms of energy storage.

Life-Cycle Break-Even Analysis of Electric Carsharing: A Comparative Study in China

Electric carsharing (ECS) is a potential option to address the problem of unsustainability in the transportation sector. The business-to-consumer model of ECS, which is one of several different electric carsharing models, has gained much popularity in recent years. Generating sufficient revenue to cover costs is a critical factor for ECS companies to maintain healthy development. This study makes an economic analysis, on the basis of life-cycle cost and monetary revenue associated with the operation of ECS, of two Chinese ECS companies: EVCARD and LCCS. Based on data gathered by field investigation, this study aims to determine the break-even moment for each company’s main vehicle models by means of the net present value method. The results show that EVCARD achieved an earlier break-even moment than LCCS. The break-even moment of Chery eQ of EVCARD was the shortest of all the vehicle models, at only 181.3 min. Moreover, a sensitivity analysis was conducted to portray how different cost-related and revenue-related factors influence the break-even moment. Our findings indicate that a wide difference exists in terms of the influence of different factors on the break-even moment. Among these, the manufacturer’s suggested retail price is the most influential variable, followed by the unit rental price. The reaction of the break-even moment to the market price of a charging pile and the non-rental revenue per vehicle—especially the latter—was found to be negligible in the sensitivity analysis.

Analyzing optimum thickness for combination of two thermal insulation materials for building walls

This paper reports an approach for analyzing optimum thickness for combination of two thermal insulation materials for walls of residential buildings on the basis of life cycle cost. Two thermal insulation materials for achieving contrast purposes can be use as a solution in many applications e.g. if fire resistant material added with Expanded polystyrene (EPS) to improve its fire resistance property, its thermal conductivity increases, where as if we select glass wool as thermal insulation material it has higher thermal conductivity but better fire resistant, thus if we wish to achieve high thermal resistance with better fire resistance at low cost we can use in place of single thermal insulation material a combination of two thermal insulation materials. In order to determine optimum thickness for combination of two thermal insulation materials there is a need to develop an approach, through which optimum insulation thickness for different combination of two thermal insulation materials on the basis of life cycle cost can be analyzed. To study the effect of fraction of one thermal insulation on optimum thermal insulation thickness proposed approach is applied to insulate external wall of a residential building envelope in heating application. Developed total cost objective function analyzed with the help of surface plot. In order to apply the developed approach EPS and glass wool are considered as thermal insulation materials. Through this approach optimum thickness for combination of two thermal insulation materials can be analyzed on the basis of life cycle cost in order to select best combination of thermal insulation materials as per requirement.

Overcoming barriers to codigestion

Codigestion of organic waste with municipal wastewater sludge is growing rapidly. It has many benefits, including diversion of organic waste from landfills, increased renewable energy from biogas production, and potential for revenue from tipping fees. However, there are still barriers to greater widespread application of codigestion. Economics, need for collaboration between utilities, impacts on wastewater application, unsupportive regulations and risks to core wastewater treatment business are obstacles that slow wider adoption of codigestion throughout the world. The research presented analyzes the economic impacts of codigestion, predicts the additional biogas production, and determines the allowable organic loading rate and fats oils and grease (FOG) addition for stable digestion operation. The economic impacts were analyzed on a life cycle cost basis and presented in terms of required tipping fees for different organic wastes, electric rates and residuals handling costs. Standard biochemical methane potential tests were conducted to estimate biogas production from various organic wastes. The specific energy loading rate (SELR) was used to express the allowable organic loading rate. Results from the economic analysis showed that codigestion using existing digesters at a municipal water reclamation facility is more economical than building new digesters. Codigestion was more economical at facilities with high electricity costs and low cost of residuals. Tipping fees for receiving organic waste would be required to offset the net cost of codigestion for wastes other than FOG. There was a net positive economic benefit of receiving FOG without a tipping fee. The upper limit of FOG for stable digestion was found to be 60 percent of the feed by chemical oxygen demand (COD). Stable digestion can be achieved with an SELR of less than 0.25 kgCOD/day/kgVS. The SELR accounts for the strength or energy content of the organic feed measured in COD. It was observed and accounted for by the SELR that anaerobic digesters loaded at higher solids concentrations (resulting in greater inventory of microorganisms in the digesters) can be fed at higher loading rates. Insights into the economics of codigestion and allowable organic loading rates for high strength organic wastes help to overcome some of the barriers to widespread application of codigestion.

Standalone solar-hydrogen systems powering Fire Contingency Networks

This paper presents a case study of a standalone fire-emergency telecommunications site in southeastern Australia to compare the relative merits of a solar-hydrogen power supply system and a conventional PV-battery system with and without diesel generator back-up. Although the power units for such applications are usually small (i.e. less than 5 kW) with relatively small capital costs, their operating and maintenance (O&M) costs can contribute considerably towards the total lifecycle cost of the system, particularly for isolated sites with limited accessibility, where frequent maintenance visits are required. Solar-hydrogen systems were found to be a more economical option on a lifecycle cost basis than traditionally-used PV-batteries (both with and without diesel generator back-up) mainly due to the inherent low O&M costs of the system. This research also found that adding a small battery bank to the solar-hydrogen system offers opportunities to improve the reliability and efficiency of the system while maintaining the economics of the system almost at the same level as that for solar-hydrogen systems.

NEKI ASPEKTI TEHNIČKIH MODELA U SISTEMU UPRAVLjANjA MOSTOVIMA

Bridge Management System (BMS) represents a rational and systematic approach to organizing and conducting of all activities related to bridge maintenance. Main goal of BMS is helping the bridge owner to make an optimal decision with respect to bridge maintenance budget, whether it is dedicated to one bridge or to group of bridges, by securing that the decision is made on the basis of Life-Cycle Cost (LCC) estimates. The structure of BMS is based on condition rating and Bridge Database (BD), Deterioration model (DM), Cost Model for evaluation of costs and Optimization Model for choosing the most rational maintenance strategy. Relationship between bridge condition rating and DM with maintenance costs within BMS is very important. Predictions regarding future intensity and rate of bridge deterioration depends on multitude of factors and it is a consequence of several simultaneous actions and deterioration processes (DP) which need to be included into DMs. DMs are mostly based on modeling of physical and chemical actions and processes or they are based on statistical analysis of large number of data regarding the condition of existing bridges, or on artificial intelligence models, etc. Stochastic models based on Markov processes are applied within more advanced contemporary BMS. Due to social and economic circumstances and lack of financial resources over the last two decades in Republic of Serbia bridge maintenance was neglected and creation of BD was discontinued. The paper deliberates some aspects of technical models within BMS, with DMs being pointed out, development of BD within bridge maintenance in Republic of Serbia and it gives an overview of sophisticated BMS and current advances in this field.

Water-supply options in arsenic-affected regions in Cambodia: Targeting the bottom income quintiles

In arsenic-affected regions of Cambodia, rural water committees and planners can choose to promote various arsenic-avoidance and/or arsenic-removal water supply systems. Each of these has different costs of providing water, subsequently born by the consumer in order to be sustainable. On a volumetric basis ($/m3-yr) and of the arsenic-avoidance options considered, small-scale public water supply – e.g., treated water provided to a central tap stand – is the most expensive option on a life-cycle cost basis. Rainwater harvesting, protected hand dug wells, and vendor-supplied water are the cheapest with a normalized present worth value, ranging from $2 to $10 per cubic meter per year of water delivered. Subsidization of capital costs is needed to make even these options affordable to the lowest (Q5) quintile. The range of arsenic-removal systems considered here, using adsorptive media, is competitive with large-scale public water supply and deep tube well systems. Both community level and household-scale systems are in a range that is affordable to the Q4 quintile, though more research and field trials are needed. At a target cost of $5.00/m3, arsenic removal systems will compete with the OpEx costs for most of the arsenic-safe water systems that are currently available. The life-cycle cost approach is a valuable method for comparing alternatives and for assessing current water supply practices as these relate to equity and the ability to pay.

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.

A Life-Cycle Cost Comparison of Exit Stairs and Occupant Evacuation Elevators in Tall Buildings

Recent changes in the International Building Code (IBC) require a third exit stair for buildings in excess of 420 ft (128 m) high. Additionally, the new code provision allows for occupant evacuation elevators (OEE) to be used as an alternative to the third stair, provided the passenger elevator be protected in such a way to facilitate safe building evacuation. In this study, we evaluate the life-cycle costs of these alternative means of egress, using two prototypical building designs. Building ‘42F’ is a 42 floor, 504 ft (154 m) high building with a total floorspace of 1.68 million ft2 (0.16 million m2). Building ‘75F’ is a 75 floor, 900 ft (274 m) high building with a total floorspace of 3.38 million ft2 (0.31 million m2), including an 8403 ft2 (781 m2) sky lobby. The life-cycle cost of the OEE is compared to two exit stair designs, differentiated by width: 44 in. (112 cm) and 66 in. (168 cm). The wider exit stair conforms with another change to the IBC that requires the increase in width of exit stairs by 50% in new sprinklered buildings. The results of the economic analysis demonstrate that: (1) an additional exit stair is a cost-effective alternative to the installation of OEE on a first-cost basis; and (2) OEE are a cost-effective alternative to the installation of an additional exit stair on a life-cycle cost basis when rental rates are moderate to high and when discount rates are moderate to low.

Identification and Characterization of Three Near-Term Direct Hydrogen PEM Fuel Cell Markets

Thirty-six pre-automotive market segments were examined to determine the market opportunity for direct hydrogen polymer electrolyte membrane fuel cells (H-PEMFC) to 2015. Potential near-term opportunities to 2008 for H-PEMFC identified include public sector emergency response, forklifts in high throughput distribution centers, and baggage tractors at airports. The telecommunications market was not analyzed because it already is a developing market for H-PEMFC. Results of the lifecycle cost analyses show that H-PEMFC offer value over existing technologies for backup power applications for emergency response radio sites when run-times of 1-3 days are required and in harsh environments which can shorten the life of batteries. For longer run-times, hydrogen fuel cost and tank rental significantly impact the competitiveness of H-PEMFC for radio sites. H-PEMFC-powered forklifts in high-productivity environments represent a promising early opportunity. However, the value of H-PEMFC-powered forklifts compared to existing alternatives is reduced for applications with lower hours of operation and declining labor rates. Improvements in hydrogen cost and fuel cell life have the greatest impact on reducing the annual cost of owning and operating a H-PEMFC-powered pallet truck. H- PEMFC-powered baggage tractors in airports are more expensive than battery-powered baggage tractors on a lifecycle cost basis. Decreasing the cost of hydrogen, increasing fuel cell life, and lowering capital cost will have the greatest impact on lowering the annual cost of owning and operating a H-PEMFC- powered baggage tractor.

Life-Cycle Cost Award Algorithms for Design/Build Highway Pavement Projects

The nation’s existing highway infrastructure was procured on a low bid basis. The recent trend towards design-build delivery offers an opportunity to compete life cycle consideration in procurement. Minimizing pavement life cycle cost will enhance the sustainability of the nation’s highways by delivering pavements that last longer and reduce waste. This study provides best-value award algorithms that can be used to procure pavement on the basis of life cycle cost rather than low bid initial costs. The study uses the Federal Highway Administration (FHWA) life cycle cost analysis (LCCA) design algorithm as a basis of the best-value award.. Two detailed case study projects were used to furnish input data and information on which to base the comparison of bestvalue award algorithms. The analysis proves that many of the current best-value award algorithms currently used in design-build projects have a strong bias to minimize the capital cost of design and construction. The analysis also shows that the LCCA input can be used, but must be heavily weighted to influence the final award decision away form the lowest proposed price.

Life-cycle cost analysis of reinforced concrete structures in marine environments

Chloride-induced corrosion of carbon steel reinforcement is the main cause of deterioration of reinforced concrete (RC) structures in marine environments. One of the ways to protect RC structures from corrosion is to use corrosion-resistant stainless steel reinforcing bars. However, stainless steel is between six and nine times more expensive than carbon steel. Thus, its use can only be justified on a life-cycle cost basis. In the paper a time-variant probabilistic model was presented to predict expected costs of repair and replacement which was then used to calculate life-cycle costs for RC structures in marine environments under different exposure conditions. Results of the life-cycle cost analysis can be applied to select optimal strategies improving durability of RC structures in marine environments, including the use of stainless steel reinforcement.

Large‐scale baseload wind power in China

This paper presents a novel strategy for developing wind power in large‐scale (multi‐GW) wind farms in China. It involves combining oversized wind farms, large‐scale electrical storage and long‐distance transmission lines to deliver ‘baseload wind power’ to distant electricity demand centers. Baseload wind power is typically more valuable to the electric utility than intermittent wind power, so that storage can be economically attractive even in instances where the cost per kWh is somewhat higher than without storage.The prospective costs for this approach to developing wind power are illustrated by modifying an oversized wind farm at Huitengxile, Inner Mongolia. The site has an average power density of 580 W/m2 at 50 m hub heights and is located 500 km north of Beijing. Using locally mass‐produced wind turbines there are good prospects that wind power would be cost‐competitive with coal power, on a lifecycle cost basis, while providing substantial net environmental benefits.Finally, the institutional challenges related to the prospect of large‐scale wind energy development are addressed. Especially important are policies aimed at developing the capacity for mass production of as much of this technology in China as is feasible. Promising instruments for speeding up the introduction of this technology include: (i) international joint ventures between foreign vendors and developers and Chinese manufacturers; and (ii) wind resource development concessions.

The cost-effectiveness of heat pumps in specific buildings in South Africa

Water heating heat pumps are extremely energy efficient and large savings can be realized when they are compared to direct electrical resistance heaters. In spite of the energy efficiency of heat pumps, a large number of residential buildings in South Africa still use electrical heaters to heat water. The reason for this is that heat pumps are considerably more expensive than electrical heaters. Building owners tend to choose the system with the smallest initial cost and do not compare the two systems on the basis of life-cycle cost. It is also difficult to calculate the life-cycle cost of a heat pump because it depends on many factors like climatological conditions and water temperature. In this paper a methodology is developed to calculate the life-cycle cost of a heat pump hot water installation. The model is used to investigate the effect of daily runtime, electricity tariff, hot water consumption and geographical location on the cost-effectiveness of heat pumps. The cost-effectiveness of heat pumps increases with daily run time, water consumption and electricity tariff. Heat pumps are more cost-effective near the coast than in the interior. If sized correctly, heat pumps are more cost-effective than electrical heaters for all major cities in South Africa. The cost-effectiveness of heat pumps for two specific buildings, one a university student hostel in Potchefstroom and the other a hotel in Durban, is also investigated. For both cases it was found that heat pumps are more cost-effective than direct electrical resistance heaters.

Light Rail/Rapid Transit: New Approaches for the Evaluation of Energy Savings, Part I - Life-Cycle Cost from Synthetic Routes/Operational Models

The energy-saving benefits of new traction technologies for light rail/rapid transit systems must be evaluated on the basis of life-cycle cost, which includes both purchase cost and energy consumption. Rigorous energy consumption evaluations previously have not been possible because of the lack of 1) a practical basis for comparing the energy consumption of different transit car/traction systems and 2) information concerning the receptivity of transit systems to available regenerative braking energy. New approaches are described that will provide a practical basis for energy consumption comparisons. Techniques for solving the complex computational problems of the receptivity of large systems are described in a companion paper [16]. Overall, a systematic approach for comparing the energy consumption of different traction systems on the basis of equal work performed (operational model) is presented. The techniques described will allow a total cost figure based on purchase price plus energy consumption to be calculated for each type of transit car on a given property basis. The concept of a synthetic route, the energy equivalent of specific transit routes under study, is introduced for comparing energy consumption values during the bidding stage, prior to system selection. This concept, which significantly simplifies the computation task, was used in predicting the annual traction energy consumption of the Toronto Transit Commission's (TTC) Presidents' Conference Committee (PCC) streetcar fleet. The computations indicated that retrofitting the fleet with fully regenerative chopper systems would reduce energy consumption by more than 50 percent. A more generalized approach, utilizing an operational model, offers additional advantages in power flow studies of transit systems to optimize substation design, feeder requirements, and fleet traction system mixtures. An evaluation using this approach predicted that the peak rush-hour power demand for the TTC fleet would be reduced by 48 percent if the streetcars were converted to regenerative chopper systems, or by a larger amount if the conversion was to idealized flywheel traction systems. Power distribution loss data also were derived for the traction systems studied.

Passive and active residential solar heating: A comparative economic analysis of select designs

This paper compares four passive solar heating concepts to a conventional air collector/rock storage system. Masonry (Trombe) and water walls are considered in the presence and absence of night insulation. The performance of optimally sized systems is evaluated on a state-by-state basis. The effects of low interest loans and National Energy Act (NBA) income tax credits are examined. With natural gas as the alternative fuel, the passive designs evaluated here offer more promise than the active system. This is true with or without inclusion of incentives, although either incentive option enhances economic performance. The passive designs evaluated in this paper are economically competitive against the electric resistance alternative in all but a few states. Moreover, on a life cycle cost basis, these designs are feasible today. Although the optimal solar fractions are generally low, passive designs offer the opportunity to incorporate solar heating into a new home at costs much less than their active counterparts. This is because there are no discernible fixed costs, thereby allowing a simple movement from zero to 100% solar when evaluating economic feasibility. When both active and passive design are shown to be cost competitive against alternative fuels, higher solar fractions will be associated with the active systems. This is principally due to the substantial fixed cost component of active systems, which forces one to achieve a given solar fraction before economic feasibility can be shown.