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

Anhang 49
Bundesamt für Energie BFE
Figure 6 Transport costs as a function of distance travelled.
Transport costs [SFr/t]
50
45
40
35
30
25
20
15
10
5
0
y = 7.620x 0.375
0 20 40 60 80 100 120 140
Average collection radius [km]
As far as the “farm-gate price” of biomass is concerned, a value of 5 /GJ was assumed (as quoted by
Infras, 2004). Considering a heating value of 18 GJ per ton of dry matter (t DM), this price
corresponds to about 135.5 CHF/t DM or 70.6 CHF/t FM. The overall cost for the feedstock was
therefore taken as 200.0 CHF/t DM (4.0 cts/kWh th ) or 104.2 CHF/t FM, delivered at the plant.
It is worth noting that such a price for woody biomass is 4.5 times higher than the price considered by
NREL in their process design (that is 23.5 CHF/t FM.), and 3.5 to 4 times higher than those indicated
in various other studies on the same topic (Hamelick, 2003; Tijmensen, 2002). The trade-off of the
effects of plant size on transport feedstock costs on the one hand, and investment costs on the other
hand, are evaluated in the subsequent section “Key determinants of production cost”.
Excess electricity was considered to be sold to the grid at 0.067 CHF/kWh e . Other costs are indicated
in Figure 7. The spreadsheet model also calculates the litres of ethanol produced, given the
composition of the feedstock considered (in this case hardwood). Therefore, each raw material’s
contribution to the cost of a litre of ethanol can be determined.
Figure 7 Details of the variable operating costs.