Potentiale zur energetischen Nutzung von Biomasse in der ... - EPFL

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costs (and consequently, the Total Project Investment) were considered to decrease by 20% from
2010 to 2025 and by another 20% by 2040. Conversion efficiency is expected to improve from 69%
in 2010 to 90% in 2060, due to the development of commercial production of more specific enzymes
and yeasts and the associated gains in ethanol yield and productivity. Operating costs were considered
to decrease regularly due to improving labour productivity as well as conversion efficiency. For a given
annual ethanol production, the plant is indeed going to consume less and less feedstock, thereby
reducing variable and fixed operating costs. As far as concerns the size of the plant, it was assumed
that second and third generation ethanol plants would be 1.5 and 2 times larger than the reference
plant, respectively. Finally, the market price of by-products was considered to remain constant over
the whole period of study.
The scenarios of evolution of the key determinants presented in Table 4 describe the reference case
considered for bioethanol production from lignocellulosic feedstocks in Switzerland. However, given
the uncertainty that surrounds most of the determinants, a sensitivity analysis was carried out in order
to illustrate the variability with respect to the reference case. The same approach was adopted for the
projected retail price of gasoline. The hypotheses and results of the sensitivity analysis are presented
and discussed in subsequent section. Interpretation of the final results should be done with caution.
Presentation of the results
Based on the cash flow analysis, the projected levelised production cost 15
of bioethanol was then
calculated for 2010, 2025 and 2040. The results are presented in Table 5. The evolution of the
structure of the production cost is also given.
Levelised production cost components 2010 2025 2040
Feedstock cost [CHF/l] 0.67 0.59 0.56
Investment cost [CHF/l] 0.61 0.42 0.27
Variable operating cost [CHF/l] 0.05 0.05 0.05
Fixed operating cost [CHF/l] 0.13 0.09 0.07
Total [CHF/l] 1.46 1.15 0.95
Total [cts/kWh ] th 24.7 19.4 16.1
Table 5 Results of the projection of future bioethanol levelised production costs.
As it can be read from Table 5, the production cost of bioethanol is expected to be reduced by 22%
(from 1.46 CHF/l to 1.15 CHF/l) at the horizon 2025, and by 35% (from 1.46 CHF/l to 0.95 CHF/l) at
the horizon 2040, with respect to the calculated production cost in 2010. One should be aware,
however, that the present result strongly depend on the hypotheses about the evolution of the key
determinants of bioethanol production costs, most of which are indeed surrounded by a significant
uncertainty.
The main characteristics of bioethanol plants envisaged at the horizon 2010, 2025 and 2040 are given
in Table 6, together with the net energy balance of the process (in terms of feedstock input, ethanol
output and excess electricity output). Although the feedstock input and ethanol production capacity
are expressed in MW th , one should bear in mind that energy-related units should be used with caution
when compared to other technologies. Indeed, ethanol is meant to be used as a fuel and the
comparison should really be done with other transportation fuels only, and using the most
appropriate reference unit, in the present case a distance travelled.
15 The levelised production cost corresponds to the selling price of ethanol which makes the NPV of the project zero.