Forest Research Institut Baden-Württemberg (FVA)
Department of forest economics
Tel: +49 761 4018 231
Fax: +49 761 4018 333
|Click here to download the Spanish translation (PDF-file)|
|Does the chipper application pay off?|
Even during the first stage of coping with damages the following questions might arise:
To answer these questions the following should be taken into consideration.
The demand for woodchips differs regionally and rises with the amount of mainly communally owned wood heat plants. An overview is available from local authorities; the upper forest authorities could possibly provide this information on the region’s demand. After calamities it should be remembered that higher production at saw mills increases the amount of offcuts This leads to a further supply pulse, which might not be compensated for by higher demands. After "Lothar" in 1999, the theoretical supply of chips in Baden-Wuerttemberg was far higher than the demand. Therefore selling was a problem. However, due to the increasing number of wood heat plants this might not necessarily be an issue following future storm events.
Generally the silvicultural need for ground clearing is not necessary, even if removal/ clearing is obligatory, e.g. for afforestation. Due to ensuing trafficking damage, clearing should only take place locally and not over the entire site. In general it’s enough to retain the remains in piles on site.
During the storm year chipping does not often occur because of the excess supply of material providing breeding grounds for beetles. Chipping can not efficiently decrease the beetle population. In the following year the remaining material is no longer suitable for beetle breeding. Only where, through a removal of all breeding material before the juvenile beetle flight stage, the beetle threat to neighbouring stands can be prevented, and where insecticide treatment can not be considered, is chipping recommended for forest protection reasons.
It is reasonable to chip along roads during full-tree harvesting under the following circumstances:
Basically two main techniques in the forest are distinguished:
The following remarks relate to the processing of spruce-tops by contractors. Expenses vary considerably depending on operating conditions and the type of chipper used.
The high costs of skidding the chip material arise from skid road distances of more then 20 m. Expenses can be reduced if the material is brought into crane range during logging or when chipping on truck roads if the material is brought into the range of the chipper by the tractors when bringing the stem wood to the truck road. Chipping in stands beyond skid roads should not be performed to avoid driving across the area/stand.
Cost-efficient chip production is possible where large quantities of wood material are accessible within the crane reach of large scale chippers. This mainly occurs near roads and conversion sites. The material needs to be skidded from the skid road to the truck road by a forwarder then gathered together.
Costs (incl. value added tax)
Chipper use is often accounted by hourly rates.
|Chipper truck (130,-- to 180,--€/h)||12-16||5-9||20-40 srm/h|
|Pre-concentration with forwarder along truck road||18-13||4-6|
|Pre-skidding into crane range along skid road1 (only at 40 m skid road distances)||26-40**||
The wood chipper drives on the skid road and chips the material within crane range. Depending on the mounted crane type, the range is 8 -10 m. Because of its comparatively large weight, use is possible on slopes up to a max. slope gradient of 20 %.
|Chipper forwarder (use of chips)||18-23||7-9||20-30 srm/h|
|Chipper forwarder (chipping and blowing on site)||16-21||6-8||25-35 srm/h|
|Pre-skidding into crane range along skid road||26-40**||
* If skid roads are 40 m apart; it’s
preferable if pre-skidding takes place during the logging of the main
** Referring to pre-skidded timber
*** Referring to total chipping volume
**** Fm: solid cubic meter, srm: loose cubic meter
Due to the high amount of wood in windthrown areas, the hectare-related clearing costs add up to more then 2,500€ (2000 figures).
For the chip transport to the heat plant an additional 2.50 –4.50 € per SRm3 (loose cubic meter, 2000 figures) has to be calculated.
For organisational reasons and due to the limited capacity of the wood chip market, temporary storage will be necessary in many cases. Basically storage as roundwood and as wood chips is distinguished. Roundwood storage is simpler and less expensive. Therefore, if storage capacity is available, timber with a high volume of compact wood should be stored in high stacks, ideally with same end first - storage so that the wood doesn’t wedge. For long term storage it is possible to cover the stack with a special fleece (WISA-WRAP, a special bitumen treated paper, which later on can be chipped along with the wood). Always try to keep costs down.
Wood chip storage is remarkable time-consuming, hence should be restricted to just the best material. Therefore small-sized compact wood with a large amount of soft or highly soiled wood should be withdrawn. The desirable roofing is cost-intensive. These additional costs can not be compensated with higher prices for better chip quality. If chips are stored in buildings, good ventilation is necessary due to moisture evaporation. Outdoor storage is possible for a period of 1 year, if consideration is given to the following:
For the temporary storage of wood chips calculate additional costs of approx. 1,50 - 4,-- €/SRm3/a (per loose cubic meter and year). Furthermore add costs for the discontinuous transport of approx. 3,-- €/SRm3 (per loose cubic meter).
Costs, depending on the process, range between 7,-- and 24,-- €/SRm3 (per loose cubic meter) ‘free on factory’ face maximum revenues of approx. 10,-- €. The wood chip marketing has to be clarified in advance. Potential costumers are mainly communal wood heat plants.
Additional savings can be realised in other work fields but its only acceptable to include them when the saved treatments are absolutely necessary. Possible fields include:
More economically interesting would be the use of wood chip by the forest owning community for its own communal heat systems (kindergarten, communal facilities etc.)