Biomass is a principal source of renewable energy in Poland. It is used directly for power production (in the combustion process and as a comfuel), as well as post-conversion into liquid fuels (engine bio-fuels) or gas fuels (biogas generated by biomass methanation in biogas plants). The domestic biogas power industry is currently a rapidly developing branch of renewable power engineering. Polish biogas plants use mainly sludge from sewage treatment plants and the organic parts of waste deposits as well as animal and farm production and food processing waste. The biogas produced is used to generate electric and thermal energy, often in co-generating systems. This paper discusses the technological processes used in biogas plants and assesses current opportunities to generate and use biogas produced in biogas plants located at sewage treatment plants, waste landfills and farm and food processing industry biogas plants.