Agricultural biogas plants in Poland: Investment process, economical and environmental aspects, biogas potential

The formal and legal requirements as well as the support system for building agricultural biogas plants in Poland have been presented. There are currently 24 agricultural biogas plants operating in Poland. The fermentation substrates are slurry, food waste and maize silage. It is most often mesophilic fermentation. Produced biogas is combusted in cogeneration and thus obtained electrical and thermal energy is used for the biogas plant's own needs and sold. The support system for biogas plants' operation in Poland is based on a system of certificates. In this system it is cost-effective to use waste for fermentation whilst it is not cost-effective for a biogas plant to run on maize silage. It has been calculated that in Poland the theoretical annual biogas potential for cattle slurry is 3646 million m3, for pig slurry it is 2581 million m3, for poultry manure it is 717 million m3, from maize after seed harvest it is 1044 million m3, from municipal waste biofraction it is 100 million m3 of biogas.