A 300-liter continuous anaerobic fermentation tank powered by solar energy for mixing. Food waste is added to the tank at a volume not exceeding 1/30 of the tank’s capacity. The amount of material added each day is equal to the amount of fertilizer discharged daily. The biogas produced is used as a substitute for household cooking gas, suitable for warming food or preparing dishes that require short cooking times and a biogas safety system has been installed.