SUSTAINABLE USE OF ENVIRONMENTAL RESOURCES: OPTIMIZATION OF LOGISTICS OPERATIONS - Energy Research Developments: Tidal Energy, Energy Efficiency and Solar Energy - page 269

Table 2.1. Objective function values for different plant capacities

Objective function value

MW €

1 0

2 0

3 65804,8

4 401101,4

5 841893,4

6 1480792

6,42 1958196

As it is evident in table 2.1, the costs trend is increasing: a maximum value of the cost
function of about

6

2 ⋅ €, for the alimentation of a plant of 6,42 MW is reached. The
optimal biomass use that corresponds to the scenarios reported in table 2.1 is reported in table
2.2. Note that, for CAP =1 and 2, the only biomasses used are industrial scraps, while for
higher plant capacities there are different type of biomasses. Different heating values ( PCI )
corresponds to different biomass kinds. As a consequence, depending on the typology that is
burnt, the same quantity of material does not involve the same energy production. The heating
value for the forest biomasses is assumed to be equal to 11.3 MJ/kg, while scraps from
pruning and from industries are considered to have a value of 12.5 MJ/kg and 16.7 MJ/kg,
respectively. In table 2.2b, the results for the case of maximum sustainable plant capacity
( CAP =6,42 MW) are reported in detail. Specifically, the use of forest parcels is the maximum
admissible and the used percentage respect to the total forest biomass present in the territory
is equal to 3.4%.

10

Table 2.2a. Used biomass for each plant capacities (in MW)

Used biomass

m 3

MW

1 20530

2 41061

3 60451

4 74030

5 86418

6 98976

6,42 104105

Table 2.2b. Typologies of used biomass for CAP =6.42 MW

Used biomass

MW 6,42

m 3

104105

% Industrial scraps

100%

% Used forest biomass

3,4%

Parcels number

373