The Capacity of Power of Biogas Plants and Their Technical Efficiency: A Case Study of Poland

The size of a company is a fundamental factor that can influence its efficiency. In larger companies, economies of scale are a key consideration. The objective of this study was to evaluate the technical efficiency of agricultural biogas plants differentiated according to their capacity of power. The study included 43 agricultural biogas plants, which were divided into three groups according to their capacity power: group I, <0.5 MW; group II, 0.5–1 MW; group III, ≥1 MW. In order to assess the technical efficiency of agricultural biogas plants under the research, the Data Envelopment Analysis (DEA) method was applied. It was found that the largest biogas plants were the most efficient. However, the technical efficiency of the smallest biogas plants was not statistically significantly different from that of the largest biogas plants. This indicates that small entities can achieve the technical efficiency at a satisfactory level. For this reason, in the development policy of agricultural biogas plants, the optimal solution is the coexistence of large and small facilities. The smallest biogas plants were more sensitive to changes in the macroeconomic environment than other biogas plants. This may suggest a need to pay more attention to energy policy mechanisms to stabilize their performance in periods of disadvantageous macroeconomic conditions.