14 Fuel science and technology (fundamental science, analysis, instrumentation)

06•02368 Steps towards the development of a certification system for sustainable bio-energy trade Lewandowski, I. and Faaij, A. P. C. Biomass und Bioenergy, 2006, 30, (2), 83 104. It is expected that international biomass trade will significantly increase in the coming years because of the possibly lower costs of imported biomass, the better supply security through diversification and the support by energy and climate policies of various countries. Concerns about potential negative effects of large-scale biomass production and export, like deforestation or the competition between food and biomass production, have led to the demand for sustainability criteria and certification systems that can control biomass trade. Because neither such criteria and indicator sets nor certification systems for sustainable biomass trade are yet available, the objective of this study is to generate information that can help to develop them. For these purposes, existing certification systems, sets of sustainability criteria or guidelines on environmental or social sound management of resources are analysed with the purpose to learn about the requirements, contents and organizational set ups of a certification system for sustainable biomass trade. First, an inventory of existing systems was made; second, their structures were analysed. Key finding from the analysis of internation- ally applied certification systems was that they are generally led by an international panel that represents all countries and stakeholders involved in the biomass production and trade activities. In third and fourth steps different approaches to formulate standards were described and a list of more than 100 social, economic, ecological and general criteria for sustainable biomass trade was extracted from the reviewed systems. Fifth, methods to formulate indicators, that make sustainability criteria measurable, and verifiers that are used to control the performance of indicators are described. It is recommended to further develop the criteria and indicator sets for sustainable biomass trade by involvement of the relevant stakeholders (e.g. biomass producer and consumer) and the analysis of local conditions (e.g. local production potentials and limits, and preferences of local people).

06102369 Supply curves of reed canary grass (Phalaris arundinacea L.) in V~isterbotten County, northern Sweden, under different EU subsidy schemes Larsson, S. Biomass and Bioener~y, 2006, 30, (1), 28 37. A partial equilibrium model with a break-even price approach was used to create supply curves for the energy crop reed canary grass (Phalaris artmd#meea L.) (RCG) in V~isterbotten County in northern Sweden. The impact of the European Union's (EU) Common Agricultural Policy (CAP) on the supply curves was studied by comparison of three different scenarios. Supply curves were created including agricultural subsidies under the current subsidy scheme, the Commission's proposal for a new subsidy scheme for implementation in 2004, and without subsidies. The geographical distribution of the potential supply was determined by the use of GIS tools. Under the current subsid~ scheme, the lowest RCG farmgate fuel price would be 56 SEK MW h . A RCG production equalling 360 GWh could be available at that fuel price level. Under the proposed subsidy scheme of 2004, a farmgate fuel price of 99 SEK MW h ~ is required for RCG production amounting to 910 GWh. In the scenario where no subsidies are disbursed, the lowest break-even price would be 115 SEK MW h 1. In all scenarios, a biofuel feedstock production from RCG equivalent to 1.3 TWh could be available at a farmgate fuel price of 116 SEK MW h ~. The RCG supply would be concentrated in the coastal area of the county, which has the most developed infrastructure and the highest population density, thus providing a nearby market for the fuel.

14 FUEL SCIENCE AND TECHNOLOGY

Fundamental science, analysis, instrumentation

06/02370 A new method for measurement of harmonic groups in power systems using wavelet analysis in the IEC standard framework Barros, J. and Diego, R. I. Electric Power Systems Research, 2006, 76, (4), 200 208.

The paper presents a new method based on the wavelet-packet transform for the analysis of harmonic groups in power systems, compatible with the standards of the International Electrotechnical Commission (IEC). The paper studies the performance of the new method in the analysis of harmonic groups and the spectral leakage associated with the presence of interharmonic components, synchro- nized and non-synchronized with the fundamental component, and also due to the loss of synchronization between the sampling window width and the fundamental frequency. Finally, the results obtained in the application of this method to different test waveforms are compared with the results obtained using the IEC method.

06•02371 A practical method for calculation of mass- attenuation coefficients of I~ particles G~rler, O. and Yal~in, S. Annals of Nuclear Energy, 2005, 32, (18), 1918-1925. A practical method to calculate mass-attenuation coefficients of /3 particles has been described. This method is based upon the analytical conclusion of/3 emission energy spectrum and the range distribution of an individual /3 particles. The mass-attenuation coefficients are obtained as the slope of the semi-log plot of theoretical calculated fraction of transmission vs the foil thicknesses. This method has been applied to obtain the mass-attenuation coefficients of /3 particles in aluminium, copper and gold. The results have been compared with the values given in previous works.

06102372 Adjusting experimental set-up improves relative permeability reliability Amaya, C.-H. Ciencia Teenologla y Futuro, 2003, 2, (4), 13-18. An improved experimental set-up for relative permeability measure- ment and interpretation methodology has been developed. The improvement aimed to meet two objectives: to modify the equipment in order to obtain more reliable experimental data and to interpret them appropriately. Special emphasis was laid upon pressure drop oscillations and uncertainties in water saturation measurements. Relative permeabilities are inferred by interpreting production data using the Johnson, Bossler and Neumann method and verifying them by simulation.

06•02373 Analysis and control of the inter-area mode phenomenon using selective one-machine infinite bus dynamic equivalents Juarez, C. T. et al. Electric Power Systems Research, 2006, 76, (4), 180- 193. New insights into the application of one-machine infinite bus (OMIB) equivalents to the analysis and study of the inter-area mode phenomenon in stressed power systems are provided. First, the notion of a time-varying OMIB equivalent is briefly reviewed and details of the adopted analytical model are introduced. On the basis of this representation, a systematic technique is then proposed to extract the underlying dynamics of the process directly from time-domain transient stability simulations. The analysis tool takes into account both, the dynamics of the slow inter-area oscillations and the dynamics of the fast inter-machine oscillations. Criteria to interpret inter-area oscillations in terms of the kinetic energy transfer between the most disturbed machines, and the rest of the system following the onset of a major contingency are given and methods to implement the proposed approach are discussed. A case study on a five-area dynamic equivalent model of the Mexican interconnected system in which several static VAR compensators are used to support system voltage is presented to illustrate the developed procedures. Studies are conducted to identify and characterize the energy transfer process that accompanies the inter-area mode separation as well as to evaluate the effect of voltage support on system damping. The results show that time-varying OMIB dynamic equivalents can be used to capture the dominant features of the inter-area mode behaviour, which are needed in the analysis and control of system dynamic performance.

06•02374 Decomposition analysis and the mean-rate-of- change index Lenzen, M. et al. Applied Energy, 2006, 83, (13), 185-198. The mean-rate-of-change index (MRCI) is a recent addition to the suite of decomposition analysis (DA) methods. In addition to the arithmetic mean used by its originators, the MRCI can be formulated incorporating any type of mean. When the logarithmic mean is used, the MRCI is equivalent to the logarithmic mean Divisia index. The MRC! is said to produce plausible decompositions, and to be able to handle negative values. However, regarding the sign and magnitude of decomposition terms, the MRCI is affected by the same distortions and inconsistencies as other DA methods, and generally does not produce more plausible results. Moreover, the MRCFs ability to handle negative values is not necessarily an advantage in DA studies using input-output data. Finally, the MRCI is not robust.

360 Fuel and Energy Abstracts September 2006