Page 236 - Materials Chemistry, Second Edition

220 4 Life Cycle Impact Assessment

because of their different operational areas. They do nonetheless recommend a
resource consumption index. 102)
The recent developments of natural gas and oil exploration using the ‘fracking’
technology are not discussed in this section. This technology will cause new
environmental problems, but may increase the static range of the two most
valuable fossil resources.

4.5.1.2.3 Further Abiotic Resources Abiotic flow resources 103) also belong to abiotic
resources in a wider sense: Solar radiation, wind, tide and currents, rain and river
waters. These resources are at present not yet recorded and assessed routinely;
however, they can be of crucial importance with regard to individual objectives,
particularly with LCA studies on renewable energies.

4.5.1.3 Cumulative Energy and Exergy Demand
The cumulative energy demand 104) (CED) is often integrated into the impact assess-
ment as means of a measure for a primary energy demand per fU. This was
common practice in the time of the proto-LCAs (Section 4.1). Because any kind
of energy demand, according to ISO criteria, does not correspond to an impact
category, a CED cannot, strictly speaking, be an indicator. In the first round of
international standardisation, CED was neither considered (not even mentioned)
in the inventory (LCI) phase (ISO 14041) nor in the impact assessment (LCIA)
phase (ISO 14042). If the metaphor is allowed, the CED was somehow trapped
between the two standards and, inspite of an integration of 14041–43 into one new
standard (14044: 2006), has since remained there.
The CED is however approved by the Dutch guidelines with an explicit reference
to ISO standards. 105) It is a very useful characterising figure 106) that can be determined
with relatively small uncertainty and it designates the overall energy demand,
including renewable forms of energy. It is therefore an ideal supplement to the
information provided by impact categories like resource consumption and climate
change concerning the fossil and nuclear energy carriers. It mainly serves to
support and assess energy saving measures. For an ecological product comparison
a product consuming less energy should obtain a bonus even if renewable energy
sources contribute to that. It is however not suitable as the sole criterion.
If CED is not integrated into the inventory where it does not, strictly speaking,
belong because of issues related to system boundaries, 107) it should be integrated
with input-oriented impact categories as an assessment value as well as into the
interpretation.

102) Brentrup et al. (2002a).
103) Udo de Haes (1996). Fossil raw materials and minerals serving as depot resources are charac-
terised by finiteness. Flow resources can however only change permanently with drastic changes
of the environment.
104) VDI (1997).
105) Guin´ ee et al. (2002).
106) Kl¨ opffer (1997b), Finnveden and Lindfors (1998) and Huijbregts et al. (2010).
107) Frischknecht reply to Kl¨ opffer and Poster G¨ oteborg.