Apart from highly efficient treatment of dairy wastewater, a low energy consumption is required in order to lower its costs. During the research period, parameters of raw and treated sewage were tested (BOD, COD, N_total, P_total). Also, the energy consumption from selected processes as well as the total consumption were measured. It was observed that about 40,5% of energy was used for aeration in SBR chambers, 14,6% for dissolved air flotation and the rest for processes connected with mechanical treatment and sewage sludge treatment. First, all the sources of energy consumption and their power were analysed. Indicators of energy consumption and removed load were calculated. The conducted research will be continued in order to optimize energy consumption while retaining high efficiency of treatment. A mathematical model will be prepared after data collecting. It can be universally applied in different WWTPs, not only dairy ones.