All extension-service advice concerning agricultural biogas plants
must begin with an estimation of the quantitative and qualitative energy
requirements of the interested party. Then, the biogas-generating potential must
be calculated on the basis of the given biomass incidence and compared to the
energy demand. Both the energy demand and the gas-generating potential, however,
are variables that cannot be very accurately determined in the planning phase.
In the case of a family-size biogas plant intended primarily as a
source of energy, implementation should only be recommended, if the plant can be
expected to cover the calculated energy demand.
Since determination of the biogas production volume depends in
part on the size of' the biogas plant, that aspect is included in this
Fig. 4.1: Balancing the energy demand with the biogas production