The assumption as shoen in Table 6.2.1 is set, although growth quantity and caloric value of biomass depend on tree types and/or local meteorological conditions.

Table 6.2.2-Table 6.2.4 obtained from references shows energy required for tree planting, describing electricity as primary energy based on power generation efficiency (38.1%) in Japan.

Table 6.2.4 shows the inventory of afforestation for pulp production in Brazil, which can be considered as an example of biomass energy production technology.

The growth rate is a value per each unit area and depends on intervals between trees. For Brazilian case, plenty of human work (task) reduces energy consumption. Energy efficiency of biomass production can be found by comparing calorific value of Table 6.2.1 and energy consumption of Tables 6.2.2- 6.2.4.

For example, North American case shows that 1.4 MJ of energy (about 7.4%) is consumed to produce biomass which has 18.8 MJ of caloric value per unit mass.