EXERGY-BASED ANALYSIS OF AN ISOLATED HONDURAS COMMUNITY

摘要

Environmental considerations are an essential part of any energy conversion assessment: especially in the analysis of natural reservations and protected areas, the concept of "environmental impact" has substantially evolved in the last decade, from an ex-post "assessment of ecological damage" to a complex, omni-comprehensive, but also pro-active and detailed, examination of the local and global implications of the interactions of anthropic processes with the biosphere. Evermore complete sets of quantitative measures of the interaction, called Environmental Indicators (EI), have been developed with the intent of providing a sufficiently accurate and reliable decision support basis for planners and decision makers. There are though some intrinsic problems about this approach, more acutely felt in the analysis of natural systems: on the one hand, generality conflicts with specificity, and it is often difficult to connect a local EI with a more global measure of environmental impact; on the other hand, several of the proposed EIs are not completely satisfactory because they lack of a sound physical basis. Extended Exergy is an indicator that seems to overcome the above limitations: it is firmly rooted in thermodynamic principles and is articulated in such a way as to constitute a reliable quantitative measure of the total amount of primary resources consumed in a given conversion chain. The indicator is derived from a quite complex bookkeeping of the exergy fluxes of the system it is applied to, and makes use of two econometric coefficients for this quantification, which are external to the theory and must be calculated on the basis of proper labour and monetary statistics. In this paper, the method is applied to a community in northern Honduras, which is sufficiently remote and ill-connected with the rest of the Country to be considered in practice as an isolated system.The application of the Extended Exergy Accounting method to such a system constitutes an important benchmark, because the Labour fluxes are much more easily measured and the monetary circulation exerts a negligible influence on the evolution of the system.