Evaluation of cost reduction potential for 1 kW class SOFC stack production: Implications for SOFC technology scenario

Recently, a commercial version of a residential solid oxide fuel cell (SOFC) system with a flat tubular cell has been developed. However, the system cost still remains very high, which is a barrier to its widespread use. In this study, the potential for cost reductions in SOFC stack production was investigated in order to contribute to the viability of the widespread use of such residential SOFC systems in future. A cost analysis of 700 W SOFC stack production based on a process integration modeling was conducted. The present bottom–up approach enabled us to perform a sensitivity analysis with a variety of parameters in terms of cell design, the production process and cell performance. This allowed us to investigate the effects of these factors on the production cost, thereby revealing the quantitative impact of each technological improvement on the cost reduction potential. The present analysis also revealed innovation pathways which could result in technology scenarios where residential SOFC systems could reach a break-even point in comparison with the baseload electricity cost. The analysis of the cost reduction potential presented here provides a useful viewpoint for developing a research strategy for state-of-the-art SOFC technology.     

Logistics cost analysis of rice straw for biomass power generation in Thailand

The logistics of the fuel supply have a large impact on the economy of a biomass power generation facility, especially for low density biomass fuels like straw. A detailed cost analysis of a typical rice straw logistics process for two baling options in three regions of Thailand shows that the costs for all logistics operations vary from a minimum of 18.75 USD/t for small rectangular bales in the Northern region of Thailand to maximum 19.89 USD/t for large rectangular bales in the North-eastern region. The difference in costs is not very significant due to the higher ownership and operating costs of the equipment for using large rectangular bales; however, the specific fuel consumption cost is substantially lower by around 17.5% and a total transport cost reduction is about 31.5%. Analysis of the logistics economies of scale for projected power plant capacities of 2-35 MW_e showed that each doubling the capacity of the energy facility increases the specific costs of the logistics operations only by around 4% in all regions.     

Pellet production from agricultural raw materials - A systems study

The demand for biofuel pellets has increased considerably in recent years, causing shortage of the traditional raw materials sawdust and wood shavings. In this study, the costs and energy requirements for the production of pellets from agricultural raw materials were analysed. The materials studied were Salix, reed canary grass, hemp, straw, screenings, rape-seed meal, rape cake and distiller’s waste. Four production scales were analysed, having an annual output of 80,000, 8000, 800 and 80 tonnes of pellets per year. It was concluded that the raw materials of greatest interest were Salix and reed canary grass. They had competitive raw material costs and acceptable fuel properties and could be mixed with sawdust in existing large-scale pelleting factories. Straw had low production costs but can cause serious ash-related problems and should, as also is the case for screenings, be avoided in small-scale burners. Hemp had high raw material costs and is of less commercial interest, while distiller’s waste, rape-seed meal and rape cake had higher alternative values when used as protein feed. The scale of production had a crucial influence on production costs. The machinery was used much more efficiently in large-scale plants, resulting in clear cost savings. Small-scale pelleting, both static and mobile, required cheap raw materials, low labour costs and long utilisation times to be profitable. In most cases, briquetting would be more commercially viable. The energy use in manufacturing pellets from air-dried crops was generally no higher than when moist sawdust was used as the raw material.     

Target Costing für Werkstoffe – Potenziale und Methodik

Target Costing for Materials – Potentialities and Methodology Target Costing is a standard instrument of cost management in business administration, but hardly mentioned in the economic oriented literature on material sciences. Nevertheless there are high potentialities for developers, producers, or users of materials regarding the improvement of efficiency. Therefore, this article will present these potentialities of a material oriented Target Costing. Besides, the general methodology of Target Costing will be modified to meet the specifics of materials from the perspectives of users of materials on the one hand and developers respectively producers of materials on the other.     

Estimating life cycle plant maintenance costs

The financial success or otherwise of a maintenance strategy can be determined realistically only when actual costs are compared with target ‘predicted’ values. This is because, in the absence of accurate cost control mechanisms, maintenance expenditure can exceed capital cost. In order to address this problem, a methodology is presented for predicting life cycle maintenance expenditure over the useful life of tracked hydraulic excavators. First, time series analysis (using a moving centred average) illustrates that the trend in maintenance cost expenditure is difficult to isolate due to large perturbations in periodic unscheduled maintenance. Such expenditure accounts for 92% of total maintenance cost. Second, cumulative costs of maintenance are modelled using a cubic equation, with time (in hours) as the predictor (x_n) variable. Model performance is robust with a coefficient of determination (R²) of 0.99 and a mean percentage error (MPE) of minus 3.94. The paper concludes with direction for future research in this field, particularly with respect to expanding the model's application to machines of various weights, manufacturers and machines operating in other industries, and determination of criteria with which to predict when a plant item will reach the end of its useful life.     

Economic design of inspection strategies to monitor dispersion in short production runs

Short-run productions are common in industrial environments where flexibility is required in the manufacturing of parts and several product variants can be produced. Monitoring process stability during the production run is strategic to avoid the occurrence of an excessive number of non conforming units which can lead to excessive scrap or rework costs. The selection of the best control strategy can be obtained with respect to an economic objective by minimizing the cost associated with the implementation strategy. In this paper, several strategies including preventive maintenance, Shewhart, EWMA and CUSUM control charts are compared to monitor process dispersion. Constraints related to the line productivity and the inspection activities configuration have been included in the problem formulation. A proper optimization algorithm has been developed to cope with the investigated problem. A large benchmark of process scenarios has been investigated and the obtained results show that the selection of the best strategy is not a straightforward task due to the influence of several process operating parameters. Finally, a numerical example is detailed to get more insight about the investigated problem.     

项目责任成本管理的几点认识与思考

工程项目责任成本管理在工程项目施工过程中,以各职能部门为责任中心,以项目成本为对象,通过各项管理对成本费用发生进行控制与考核,实现工程项目利润最大化。     

Bi-objective minimization of environmental impact and cost in utility plants

A methodology to minimize potential environmental impact and operating cost in the selection of the operating conditions of a steam and power plant is presented. A bi-objective mixed integer nonlinear programming problem is formulated and solved in GAMS. Different strategies are implemented successfully to generate the Pareto curve such as: minimum distance to the utopia point, ?-constraint, weighted sum and global criterion. An analysis of the Pareto curve allows the identification of two regions where it is cheaper and more expensive respectively, to reduce the potential environmental impact, providing relevant information to support a decision making process. The economical valorisation of greenhouse gases emissions reduction was also carried out, showing the region of the Pareto curve in which the income would compensate the increment in operating cost, leading to a reduction of the potential environmental impact with no extra cost.     

Incentives for cost reduction and cost padding in electricity markets with overlapping “green” regulations

We examine overlapping regulations in electricity markets. Using an example based on a stylized model of a competitive energy market, we study cost-reduction and cost-padding incentives by “green-energy” producers in an electricity market employing an emissions tax and the simultaneous use of a green quota for the generation portfolio and a fair rate-of-return constraint implemented via a system of feed-in tariffs. We show inter alia that when subsidies are phased out, exploitation of the green technologies full cost-reduction potential is a Nash Equilibrium but emissions will increase. In addition, green-energy producers can engage in collusive cost padding to increase profits even as they satisfy the policymaker's desired green quota.     

Reactive power pricing structure for hydroelectric power station in condenser mode operation

Reactive power support is critical for system security and pricing of reactive power is a vital issue in restructured environment. Peaking units at hydroelectric power plant in condenser mode operation can provide major reactive power support. Therefore costing structure for hydroelectric power plant incorporating various cost components in condenser mode operation is presented in this paper. Major cost components include capital cost component, changeover cost component and a cost component related to number of service hours in condenser mode operation. A methodology is proposed based on these components. A case study of Koyna Hydro Electric Power Plant (KHEPP) is elaborated.