National Contact Point for Renewable Energy Sources

Biogas Systems (Landfill, Wastewater Treatment Plant, Other)

Biogas systems are facilities that produce energy from biogas obtained primarily through the fermentation of plant biomass, animal manure, organic waste (e.g., from the food industry), municipal waste, slaughterhouse waste, or biological sludge from wastewater.

Energy obtained from biogas is classified as originating from renewable energy sources under the provisions of the RES Act. The detailed course of the biogas production process depends on the type of biogas system. In most cases, the produced biogas is used on-site for the combined generation of electricity and heat. Other biogas systems process and purify biogas into biomethane and inject it into the gas grid or subject it to liquefaction or compression processes, transporting the gaseous fuel by means other than gas networks. As a by-product of biogas system operation, post-fermentation residue (digestate) is obtained. Its use depends on the composition of the biomass used for biogas production; however, digestate is most often used in agriculture:

a) as a fertilizer or plant growth aid, based on the provisions of the Act on Fertilizers and Fertilization, after meeting the requirements for obtaining a permit for placing on the market (pursuant to Article 4 of the said Act);

b) as part of waste processing under recovery procedure R10, based on the provisions of the Waste Act, after obtaining a permit for waste processing under procedure R10, as referred to in Article 42(2) of the said Act.

A specific type of system is the landfill biogas system, which uses biomass located in landfills to produce biogas.

Landfill biogas systems are primarily intended for the energy use of biogas generated from biodegradable waste in a landfill. Therefore, an investor interested in building a landfill biogas system should carry out the investment and construction process related to the construction of a landfill or the construction of a biogas system at an existing landfill. According to the Regulation of the Minister of the Environment of 30 April 2013 on landfills, every landfill where biodegradable waste is expected to be deposited should be equipped with an installation for the collection of landfill gas. Landfill gas should be purified and used for energy purposes (through landfill biogas systems), and if this is not possible – burned. Such management of landfill gas reduces fire and explosion hazards and the risk of local atmospheric contamination.

Landfill biogas systems usually form an integral part of the landfill and are covered by a common construction permit for the landfill. Therefore, an investor interested in building a landfill biogas system should remember to include in the application for a landfill construction permit information on the method of collecting, purifying, and utilizing or neutralizing landfill gas in accordance with Article 127(4)(8) of the Waste Act.

One variant of biogas system operation is its connection with the activities of a wastewater treatment plant. Biomass from wastewater treatment plants can be used for biogas production, which seems to be a beneficial way of managing sewage waste, especially in the context of the prohibition on landfilling sewage waste under Article 122 of the Waste Act.

The technology for producing biogas from wastewater treatment plants is based primarily on the use of sludge fermentation chambers and the collection and purification of biogas for energy use, most often in cogeneration units. Unlike other types of biogas systems, installations processing sewage sludge have a certain inflow of substrate, which they generally do not have to compete for. Therefore, a biogas system at a wastewater treatment plant constitutes a reliable source of both electricity and heat. The investment process for biogas systems at wastewater treatment plants follows the general principles presented for biogas systems. The investor should pay particular attention to environmental permits related to the operation of this type of biogas system.