In order to obtain the total costs associated with the delivery of woody biomass in dried form to the selected power plants from the selected procurement areas in North America, Goerndt et al. (2013) considered both of the marginal operational costs (i. e. costs of stumpage, harvesting, chipping) and the transportation costs. It was observed that a portion of the transportation costs of woody biomass to the power plants located in respective area is fully influenced by the maximum transport dis­tance. Therefore, the maximum transport distance (d) to carry a mega-gram biomass is calculated by using the formula shown in Eq. 12.8, and is based on the similar assumption of Eq. 12.7 that the biomass being collected is evenly distributed within the given radius of a plant (Huang et al. 2009; Overend 1982):

d = Rt (12.8)

Where R corresponds to the biomass procurement radius in kilometres and т represents the tortuosity factor, i. e. the ratio of road transport distance to line-of-sight distance which generally varies in the range of 1.2-1.5 as per the geographic location (Huang et al. 2009; Perez-Verdin et al. 2009).

According to Goemdt et al. (2013) therefore, the total delivery cost (C) for the woody biomass in each procurement area and procurement regime can be calculated by using the following Eq. 12.9:

C = (Tv d) + Tf (12.9)

Where d represents the maximum transport distance of biomass, Tv corresponds to the costs related to incremental transportation and Tf is the operational costs which includes loading/unloading of biomass in trucks.