Life Cycle Inventory of Brazilian hydroelectric generation- Itaipu Power Plant: first approximation. / "Inventário de ciclo de vida da geração hidrelétrica no Brasil - Usina de Itaipu: primeira aproximação"

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The Life Cycle Assessment (LCA) has been proven to be an important environmental assessment tool, mainly due to its “focus on function”, which allows the consideration of the environmental performance of products, itself a proceeding that has been more and more requested by different social actors. However, for LCA to be widely and trustfully used, the development of local data bases containing Life Cycle Inventories (LCI) of the most used inputs (energy, raw materials, etc.) is necessary. The present thesis is part of a project conducted by GP2- Group of Pollution Prevention - Escola Politécnica/ USP, which aims to develop and make available a Brazilian LCA data base. Specifically, it focuses electricity generation. In order to allow this project to be concluded in a masters degree context, it was adopted as a simplification the electricity generation in Itaipu Hydropower Plant, responsible for 22,4% of Brazilian consumption in 2000. As a first step towards the elaboration of the LCI, a review on LCA use on hydropower plants was conducted, establishing general recommendations. On the following, Itaipu project was studied concerning its initial civil works and the materials consumption on construction and operation within a 100 year period, obtaining as a result a LCI with the most significant environmental burdens in terms of generated energy (MWh). The system boundaries on this context includes: excavations and other earthen works; building site installation and operation; transportation of: workers, cement, ashes, structural steel and diesel; life cycle of steel, copper, cement, diesel, lubricant oil and transformer oil used on the dam and permanent equipment; (including maintenance and substitution); and reservoir filling. The results demonstrate, besides the importance of data homogeneity, that the LCI is extremely sensitive to the considered lifetime, which confirms that the construction phase is the main source of environmental burdens. Another important conclusion is that each hydropower plant is a particular case, and it is not possible to establish typical values for the environmental burdens. However there is an indication that Itaipu has a better environmental performance than other plants, mainly on respect to the energy pay back period, due to its high capacity factor and installed power. According to the estimates, the process which most contributes to the environmental burdens of hydropower plants life cycle are: reservoir filling; steel and cement life cycle; and operation of construction machines. Transport activities are of no relevance, however the steel consumption on permanent equipment is. Compared to thermal power, hydropower life cycle air emissions and water consumption are shown to be significantly lower. This comparison indeed is restricted only to this burdens. Finally, recommendations are presented, in the spirit of refining boundaries in the following studies, and the objectives attained are commented. It should be highlighted that all hypothesis and calculations are located in the Annex volume, being just referenced on the main text.

ASSUNTO(S)

itaipu power plant gestão ambiental life cycle assessment usina itaipu environmental management geração hidrelétrica inventário de ciclo de vida ciclo de vida life cycle inventory análise de ciclo de vida life cycle hydroelectric generation

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