Page 314 - Materials Chemistry, Second Edition

298 4 Life Cycle Impact Assessment

4.6.1.5 Resource Demand
For an evaluation of the resource demand within the impact assessment,
the scarcity of resources is usually used as criterion. Despite an alleged
good accessibility of the environmental aspect ‘resource demand’ some
fundamental aspects will have to be clarified in future. This is of particular
concern for a meaningful classification of resource types and for the definition
of scarcity.
Because of a pre-selection of priority impact categories in this study only
the categories energy resources and land use are described.

4.6.1.5.1 Energy Resources

In this study an aggregation of the resource ‘energy’ is twofold: On the one
hand the concept of its evaluation as cumulative primary energy demand
(CED) is applied, on the other hand the finiteness of fossil primary energy
sources is considered.
Cumulative Energy Demand

The CED is not an impact parameter but an inventory figure. Nevertheless it is
used in the study as important information in the interpretation and is therefore
specified here.

CED is applied as a category for the evaluation of primary energy.
It is an inventory parameter and represents the sum of the energy content
of all primary energy sources, which can be traced back to the system
boundaries. ‘CED fossil’ is the sum of exclusively fossil primary energy
sources. The consumption of uranium is assessed by ‘CED nuclear’. The
computation of ‘CED nuclear’ is done by an efficiency mark-up of 33% of
the electricity generated by nuclear power used by the investigated systems.
Besides, the ‘CED water power’, ‘CED renewable’ and ‘CED other’ as well
as the ‘CED sum’ of all CED values as a result of the inventory is listed.
‘CED other’ is assessed as an energy demand related to data records with no
information concerning the type of energy production. ‘CED water power’ is
based on an efficiency of 85%.
Scarcity of Fossil Fuels

According to the method of the UBA the static range of energy sources
serves as an indicator for the scarcity of fossil fuels. 371) The static range
is derived from the data of the world reserve and current consumption of
the respective resource. The scarcity is converted into crude oil equivalence
factor (ROE) (UBA, 1995).

377) The reliability of the static range as scarceness indicator is impaired by uncertainties concerning
the state of known and economically exploitable resources.