"In the first year alone, the plant ran for 8,240 hours. We use gasifier to generate clean energy for our guesthouse and a local heating network, and on top of that, we have a further source of income from wood chip drying", Obernosterer family.
"Haus Blatthofer" guesthouse is located in the beautiful Lesach Valley in Austria. In addition to the guesthouse, the gasifier from Re² supplies a local heating network and wood chip dryer with heat.
As the contract drying operation takes place in summer, all the heat can be fed into the local heating network in winter. A well thought-out wood chip management system rounds off the energy concept and provides additional income through the contract drying. Anton Obernosterer put his wood gasifier with 30 kWel into operation in June 2015. In its first year of operation, the plant's capacity utilization was around 94% at 8,240 hours. A existing heating boiler covers the peak load in winter.
Wood chip industry as another source of income
The family obtain some of its wood chips from its own eight-hectare forest. However, due to the difficult management, additional wood is purchased. The wood chips, which are processed into wood chips by an external company, are dried in a simple bunker dryer.
Information wood chip drying:
- Storage hall for large volumes of wet and dry wood chips and hay: 250 to 300 m3
- Bunker drying for wood chips and hay: 100 m3
- The wood gasifier is supplied with wood chips directly from the storage bunker
- The storage bunker is equipped with an 8 m long and 4 m wide moving floor
Interview with Anton Obernosterer:
Hi Anton, the village of St. Lorenzen is quite small and your former farm is also tightly framed by the surrounding buildings. You also have a sloping site here. At first glance, the entire plant looks like a small factory in an old barn. How does the logistics of the plant work? Let's start with the production of wood chips...
Since there only is an access road around the barn, the wood chips are produced outside the village. This is a local community cooperation. The logs from the adjacent wooded areas are jointly purchased, stored and shredded for a good price. The own, difficult forest management is therefore not really necessary. The shredded goods are then delivered with a loading vehicle to my farm and immediately unloaded.
What happens now has essentially been planned and built by the company of Hubert Weissteiner - a friend. How does the entire process work?
There is a crane below the roof, which can traverse the barn and also swivel out. The crane unloads the loading vehicle, no matter whether it is wood chips or hay and deposits the still moist product in the central storage area in the barn. From there, the product to be dried is moved into the drying hopper. The crane moves the dry wood chips into the adjacent storage hopper with the push floor. Dried hay will then be returned to the storage area or directly loaded onto a loading vehicle. The drying of wood chips or hay is timed in order to utilise the storage area accordingly.
How do you prepare the wood chips?
The push floor inside the storage hopper conveys the wood chips to a transverse auger. The subsequent conveyor system then discharges the fines and long parts as the delivered wood chip quality can easily vary. Fines and long parts end up in the storage for the wood chip heating system. In the push floor, a final drying process is taking place ensuring a perfect wood chip quality after the sieving. The good wood chip quality is the basis for the reliable operation as the local heat network has to be supplied with heat and preferably without failing.
Your "electricity and heat factory“ is really well-thought out; how must time do you have to put in for this?
For the operation of the wood gasifier as well as the CHP only 2 to 3 hours maximum. Often, the machines operate non-stop for 14 days. Since I dry wood chips and hay during the warm season, this is where actual work is to be done, depending on the volume of the product to be dried.