BIOENERGY FOR EUROPE: WHICH ONES FIT BEST?

154 7 Annex
7.1.8 Country specific results – Switzerland
Introduction
The three Swiss biofuels RME, wood and biogas are shown in comparison with their fossil counterparts.
The results are presented per MJ useful energy, which means that efficiency factors (0.36 for
diesel engine, 0.75 for a wood boiler, 0.9 for oil and gas boiler and 0.8 for gas in order to produce electricity
and heat) are already taken into account. The contributions of the agricultural/forestry parts and
the energy production are shown in detail to enhance a clear assessment. The agricultural/forestry part
contains all processes on the fields, on the farm or in the forest until farm gate for the biofuel crop as
well as for the reference crop. Energy production for biofuels starts with transport from farm and contains
all subsequent processes, whereas in energy production of fossil fuels all processes are included.
The biogas plant belongs to the energy production, the distribution of the slurry belongs to the agricultural
part. It is unfortunately possible to assess the influence of the allocation procedures for RME only
partly, although the contributions of the substituted systems for glycerine and rape seed meal can be
bigger than the absolute values shown. The – negative or positive – consequences on soil ecotoxicity
(due to wood decay for example), which can play an important role from an environmental point of
view, could not be assessed in the project.
Use of fossil fuels – Switzerland
All biofuels consume less fossil fuels per MJ useful energy produced than their fossil counterparts (see
result diagram below). The fossil energy demand from RME results mainly from the machinery and
fertilisers used in the rape seed growing. Due to the system expansion with soy beans there is even a
small bonus in the transesterification step. The diesel system needs almost four times as much fossil
energy although the fallow does hardly consume any. Heating oil and natural gas need around 80 times
more fossil energy than wood logs for heating. The natural gas system for electricity and heat uses
about 3.5 times more fossil energy than the biogas system (with both times the same energy demand for
the distribution of the slurry). The biofuel needing the least fossil energy per MJ useful energy is by far
wood logs for heat with only 0.01 MJ (see result diagram below). Biogas needs roughly 40 times more
energy with 0.4 MJ and RME even 70 times more with 0.96 MJ. The latter fact is not only due to the
energy consuming required for growing of rape seed, but also due to the much lower efficiency of the
diesel engine compared to the wood boiler. For comparisons between the biofuels one would have to
take into account the different system boundaries.
4,0
3,5
3,0
2,5
2,0
1,5
1,0
0,5
0,0
0,085 are subtracted
due to system
expansion
Primary energy demand (MJ/MJ useful energy)
Processing & utilisation
Agriculture/forestry part
Fossil fuel life cycle
Agricultural reference system
RME Diesel Wood Heating oil Natural Gas Biogas Natural Gas
Greenhouse effect (greenhouse warming potential GWP) for 500 years – Switzerland
All biofuels have a lower GWP than their respective fossil reference systems (see result diagram below)
The GWP for RME origins mostly from the nitrous oxide (N2O) formed due to fertilisation, whereas the
burden for diesel is almost entirely due to the fossil carbon dioxide (CO2) at combustion. The difference