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

GIS model 183
Bundesamt für Energie BFE
Option 2: Chipping at the forest route
This technique is applicable in passable areas in pure and mixed forest stands for chipping trees of large
diameter (coniferous species: dbh > 40 cm; deciduous: dbh > 30 cm). The trees are felled, sorted out
and put down at the edge of a moving lane. A Forwarder vehicle picks up the assortments of timber
qualified as “energy wood” and moves it to the forest route. A mobile chipper travels through the forest
route and chops the wood blowing chips into a tilting container. When the capacity of the tilting
container is reached, the mobile chipper drives to the larger roll-off container, which is further
transported by truck to the end-use consumer. The costs incurred through the use of this technology
option are given in Table 50. In this case the costs of felling/extraction of trees are allocated to other
timber assortments (construction and industry wood) for both types of species.
Option 3: Chipping at the forest route (extraction method: dragging by soil)
This type of timber harvesting technique is applicable in the forest stands which are not accessible for
motor vehicles. It can be applied in pure and mixed stands for felling/extraction of trees of smaller
diameter (coniferous species: dbh < 15 cm, deciduous species: dbh < 30 cm) and for distances from
the nearest accessible road not exceeding 100 m. The trees are felled with a chain saw and extracted
with a radio-controlled tractor to the forest route or motorway. Then the trees extracted from the forest
are taken up by a mobile chipper, which chops the wood and blows the chips into an adjacent tilting
container. When the capacity of the tilting container is reached, the mobile chipper drives to the larger
roll-off container located in the area accessible for road trucks. The roll-off container is further
transported by truck to the final destination point. The costs of using this technique are given in Table
50.
Option 4: Chipping at the forest route (extraction method: cable crane)
This is another type of technique applicable for harvesting timber in the forest stands which are not
accessible for motor vehicles. It could be applied in pure and mixed forests for felling/extraction of trees
which can not be extracted using the technique of Option 3. The trees are felled with chain saws and if
necessary classified in assortments. With the use of a cable crane the trees are evacuated towards the
nearest forest route to the maximum allowable distance of 600 m. Then the standard chipping
technique and machinery can be applied to produce wood chips that could be further transported in
large roll-off containers to the end-use consumer. The costs related to the use of the cable crane
technology option are given in Table 50.
Option 5a: Chipping at the end-use facility: felling/extraction of trees in motor vehicle accessible
areas (alternative to Option 2)
This harvesting technique can be used in pure and mixed forests as an alternative to Option 2. It is
suitable for harvesting and chopping of energy wood of large diameter (coniferous species:
dbh > 40 cm; deciduous: dbh > 30 cm) in pure and mixed forest stands. The trees are felled, sorted out
and stocked at the edge of harvesting vehicle’s moving lane inside the forest stand. A Forwarder vehicle
picks up the timber extracted from forest; moves it to the nearest truck accessible road and stores it
there. The assortment of timber qualified as energy wood is further transported by truck to the end-use
facility. Then a large-size chopping device is employed to transform energy wood into chips. The costs of
using this technique are given in Table 50. Since the diameter of trees is big enough to allow alternative
use of timber, therefore the costs of felling/extraction of trees were allocated to other timber
assortments (construction and industry wood).
Option 5b: Chipping at the end-use facility: extraction of trees with cable crane from inaccessible
areas (alternative to Option 4)
This technology option represents an alternative to the Option 4. It can be used in pure and mixed
forests in areas not accessible for motor vehicles. Similarly to the technique of Option 4 it is suitable for