Page 216 - Materials Chemistry, Second Edition

204 E. Martínez Cámara et al.
Table 2 Summary of the materials and manufacturing energy used in the main components
(Martínez et al. 2009)
Component Materials Energy
Foundation 700 Concrete T 5.12 MWh
25 Iron T
15 Steel T
Tower 143 Steel T 47.2 MWh
Nacelle 18.5 Iron T 287.11 MWh
21.69 Steel T
0.35 Silica T
3.5 Copper T
0.8 Fiberglass T
1.2 Resin T
Rotor 11.89 Resin T 33.1 MWh
7.92 Fiberglass T
14 Cast iron T

effort, resource requirements, and time with no loss of quality in the final results
obtained.
As mentioned above, the first step is to establish cutoff criteria for the system to
be studied. The study conducted here includes all the elements of the foundations
on which the wind turbine is supported, plus the other main components (tower,
nacelle, and rotor). It excludes all the elements that comprise the system of con-
nection with the electricity distribution and transmission network (medium voltage
lines and transformer substation).
The main cutoff criterion used is the weight of each component in relation to
the total weight of the system under study. Despite the use of this cutoff criterion,
which would be not valid in general cases, when applying it we have taken into
account the necessity of not to exclude the components or materials which, in spite
of its relatively low weight in the system, may present a significant environmental
impact. This considerably reduces the number of small components that need to be
analyzed individually and for which specific data must be compiled, but does not
appreciably affect the final results. It also makes the LCA more flexible, enabling
major changes to be incorporated into the system more quickly and easily.
The data used to define and characterize each of the main components are taken
from a database supplied by the component manufacturer. The main data collected
are the following: raw materials required for manufacture, energy consumed in the
associated manufacturing processes, and details of the transportation of materials
and components.
The basic assumptions made in the wind power system LCA are the following:
• The weight of the main components is used as the cutoff criterion to determine
whether or not they are included in the life-cycle inventory. The sum total of the
components considered in the analysis accounts for 95 % of the weight of the