The aim of this paper was to determine the potential of biogas produced in anaerobic fermentation depending on the COD (Chemical Oxygen Demand) in raw wastewater of a cho-sen Brewery. This paper covers two parts, the theoretical and the empirical. Results of re-search work has been developed on the basis of data provided by the brewery. On the basis of the quantity of raw sewage COD content was determined daily and the daily production of biogas. Calculations allowed to get the result of the total energy contained in the fuel and the nominal power of the generator in a cogeneration system ...