Farmer condition will influence investment value and operational cost. In some conditions in Indonesia, rural area
is still larger and farmers have larger land that have not been processed or utilized for any purpose. In this case,
investment of biogas as energy source for electricity power generation does not need cost for land investment. It is
also considered that the operational of biogas system is relatively easy, simple, and just need short time that the
farmers can do digester feeding and maintaining the installation as part of their activity in raising their cows. In this
case, the farmers do not need to pay some labors to operate the biogas system. Therefore, this research will study
economic feasibility of small scale biogas power generation system in various farmers investment condition, i.e. in
the case that both land investment and labor operation cost is required (Case A), in the case that land investment is
not required but labor cost is required (Case B), in the case that labor cost is not required but land investment is
required (Case C), and in the case that both land investment and labor cost is not required (Case D).