How to analyse and maximise the forest fuel supply availability to power plants in Eastern Finland

The annual use of forest fuels has grown rapidly in Finland during the 21st century. In 2007 the annual use was 5.3 TWh (firewood use excluded), whereas the targeted growth by the year 2010 is 10.6 TWh, i.e. some 5 million m3. The purpose of this work was to evaluate the maximum availability of forest fuels to CHP plants in Eastern Finland. The total availability to the selected CHP plant population was 7 TWh at the maximum transport distance of 100 km. The main share came from logging residues, 3.3 TWh, and the rest from stumps, 1.8 TWh, and small diameter energy wood, 1.9 TWh. The highest plant-specific availability reached the level of 1.7–1.8 TWh, but the overlapping procurement areas reduced the availability for most plants to a level less than 1 TWh. In all plant sites peat fuel could be partially compensated with forest fuels according to availability, but not completely due to the boiler technology. Increasing the targeted national forest fuel use presupposes the use of new logistics supply solutions, such as other transport modes and regional buffer storage networks. This makes it possible to widen the traditional procurement area-based on truck transportation, which is less than 60 km because of a dense plant network.