Page 101 - Materials Chemistry, Second Edition

3.2 Energy Analysis 85

There are impact categories (aquatic ecotoxicity, human toxicity and land use)
and product groups (photovoltaics and wind energy), which strongly depend on
capital goods. In any case it should be carefully examined whether by use of
infrastructure data consistency and symmetry problems occur, particularly in
comparative LCAs.

3.2.4
Supply of Electricity

Electricity as a special form of energy plays an important role in LCA. It has already
been pointed out that the evaluation of the primary energy within this form of
energy is particularly urgent (see Section 3.2.2). On the basis of the second principle
of thermodynamics, conversion losses have been identified: only around 30–40%
of thermal energy can be converted into electrical energy in conventional thermal
power stations. The remainder could largely be used as low temperature input for
heating; contrary to the practice in Sweden, this is not yet common practice in
Germany.
The notion ‘electricity mix’ is of fundamental importance for a specification of
average supply levels – and thus for calculating the primary energies – of national
grids. They are rarely supplied with one kind of primary energy alone (exceptions:
90–100% hydropower in Norway and Brazil; about 80% nuclear power in France)
(see also Table 3.2). Rather, a mixture of the following sources is typical:
• Fossil energy sources (hard coal and lignite, natural gas and oil),
• nuclear energy,
• hydropower,
• renewable energy sources without hydropower (biomass, wind energy, solar
energy, etc.) and
• import (weighted mix of countries exporting into the country under examination).

If the manufacturing plants of the examined product are scattered all over
Europe, a European electricity-mix is often applied. For these average values, the
Western European Electricity Network is often used as the basis. The Union for the
Coordination of Transmission of Electricity (UCTE) 67) is, with 2530 TWh (2006),
one of the largest electricity networks of the world. The transnational energy flow
within the UCTE amounted to approximately 297 TWh in 2006, amounting to 12%
of the produced quantity of electricity. The Scandinavian states (except Denmark
west), Great Britain and Ireland as well as the Baltic States and the GUS states have
their own networks. For Continental Europe the UCTE is a good approximation.
The publicly accessible statistics of the UCTE, however, show small resolution
with respect to the primary energies used. An improved resolution is provided by
the country specific statistics of the International Energy Agency (IEA) for EU-27.
Table 3.5 presents the electricity mix data of 2005 for the European Union and

67) www.ucte.org, see also BUWAL, 1991 (UCTE since 1999; 1951–1998: ‘Union pour la Coordination
de la Production et du Transport de l’Electricit´ e’ (UCPTE).