Effects of supply chain strategy on stump fuel cost: a simulation approach.

In Sweden, stump fuel extraction for energy purposes is not a well-established practice and this major resource is currently left in the forest. The stump fuel supply chain is both challenging and complex, due to distance between resource and end user, material bulkiness, and the number of subprocesses involved. This study examined the impact of different aspects such as site characteristics, fuel quality, biomass losses, and machine performance on fuel cost. Two systems, including transport of comminuted and uncomminuted fuel, were studied. Discrete-event simulation was used to model systems and to analyse the dynamics of the supply chain and its various components. For a distance of 10 km, transportation of uncomminuted fuel gave the lowest costs. For distances from 30 to 70 km, site size (odt) determined whether to comminute or not before transport. For longer distances, comminution before transport proved to be necessary. Well-planned stump storage was shown to reduce the delivery costs significantly, while high moisture content (>45%) had detrimental effects on system costs per unit energy delivered. However, the most influential parameters were productivity level and site characteristics (distance and site size).