Page 275 - Materials Chemistry, Second Edition

Hydropower Life-Cycle Inventories 265

A last observation regarding process is that compared with the civil works
machine operation, the unit process of transports included on the materials life
cycle had proved to be not significant. This conclusion must be observed carefully,
owing to the huge amount of civil work on Itaipu case, which should not be
directly repeated in other hydropower schemes.
The initiative was considered successful once it opens the perspective to make
more precise Brazilian LCIs, which are actually on development. It is believed that
the availability of representative datasets for Brazilian conditions will improve
readiness, quality, and accuracy to LCA studies, all of them, indispensable con-
ditions to incorporate this important tool into the Brazilian environmental man-
agement community.

5.1 General Guidelines for the Elaboration
of a Hydropower LCI

From the conclusion obtained from the Itaipu case study, it was possible to pro-
pose some guidelines for LCI to be performed hereafter over the hydropower
domain. The most remarkable recommendations are as follows:
• Use ‘‘generated electricity’’ as the product system function. Do not include other
uses of the reservoir as function of the product system, except on the case the
reservoir had a previous usage other than generate energy;
• Establish the Functional Unit (FU) using the electricity unit of measure;
• Adopt the period of 100 years as a standard time horizon. In this frame,
maintenance operation required to keep the plant operative along the period
must be considered;
• Focus the attention on data collection on the processes of: civil machines
operations; steel, cement, diesel, and copper life-cycles; materials used by the
electromechanical equipment; transportation of raw materials and employees;
land occupation and transformation; and GHG emissions from the reservoir
filling;
• Develop the LCI with procedures that search for homogeneity of criteria on data
collection;
• Conduct procedures as Muster Pedigree and Monte Carlo Analysis, in order to
estimate uncertainties of the LCI. The use of LCIA can be an important kick off
on this kind of analysis; and
• Develop the LCI with a multidisciplinary team of practitioners, with task-spe-
cific focus and frequent meetings to share impressions, discuss results and
debate hypothesis to be used.
The recommendations above must be taken carefully, considering that each
case study differs from the others.