Life-Cycle-Assessment for Stoves and Ovens - ESU-services Ltd.

Impact Assessment
3.2 Comparison of all Cooking Alternatives
Fig. 5 shows the relative environmental impacts of various cooking alternatives in comparison
to the alternative with maximum impacts. This figure is calculated with the efficiencies
estimated for the cookstoves 24 . Cooking with the kerosene stove shows the highest 22 scores
for ecotoxicity. The 3-stone fire shows to have the highest impacts while using the concept of
Eco-indicator 95+. Cooking with electricity has the highest impact in case of radioactivity
and space use (in Switzerland) or waste heat (in Western-Germany).
The use of LPG for cooking shows to have higher impacts for all investigated impacts than
the use of natural gas. The production of LPG is calculated in ECOINVENT based on the assumption,
that the fuel is produced from crude oil in refineries (Frischknecht et al. 1996). It is
also possible to produce LPG directly from natural gas with less environmental impacts, but
the share of this production option for the LPG consumed in Switzerland 23 is relative
small.
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
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Nutzwaerme ab Elektroherd W-D Nutzwaerme ab Elektroherd CH
Nutzwaerme ab Fluessiggasherd Nutzwaerme ab Holzherd
Nutzwaerme ab Mikrowelle CH
Nutzwaerme ab 3 Steinefeuer
Nutzwaerme ab Gasherd
Nutzwaerme ab Petroleumkocher
Flaecheninanspruchnahme Aquatische Oekotoxizitaet Terrestrische Oekotoxizitaet Radioaktivitaet Abwaerme EI Total
Fig. 5 Relative comparison of all investigated cooking alternatives in comparison to the alternative with the
highest impacts (Value = 1 in the figure)
3.3 Influence of the Efficiency for the Results
A more detailed investigation will now look on the influence of the efficiency for the stove
used. The range of efficiencies likely for the different types of stoves is given in Fig. 3 in
22 Cooking with kerosene was not investigated in detail for this study. The emission figures of the stove are
based on measurements for stoves in developing countries. It is possible, that the environmental impacts due to
the cookstove emissions might have been overestimated in this report.
23 In 1996, 83% of liquefied gas consumed was produced in Swiss refineries. The bulk of gas imported came
from Germany (90%) and other European countries. These countries have a small proportion of national natural
gas extraction and do produce LPG also mainly in refineries. Thus it can be assumed that the simplification of
solely production in refineries does not influence the results much (Personal communication with Dr. Berg,
Erdöl-Vereinigung, Zurich, 4.6.97).
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