Grass to biogas in Kněžice
The municipality of Kněžice is unique example of an ambitious renewable energy project in Central Bohemia on the municipal level. Since 2007 it operates a biogas plant and solid biomass heating plant providing heat to the majority of local households and institutions and selling electricity to the grid. The cooperation with the greenGain project brought attention to grass mowed on public spaces and along roads to be utilized in the local biogas plant. Around 50 tonnes of herbaceous materials are harvested within the Kněžice settlement during the vegetation period. The volumes are relatively small as it roughly represents the daily consumption of the facility, predominantly fed with manure, agricultural residues or food waste.
The utilization of herbaceous biomass from public green spaces is viewed in Kněžice as an interesting complementary feedstock as the public green spaces have to be maintained anyway and the use in the biogas plant increases the production of energy. Milan Kazda, the Mayor of Kněžice municipality, would like to broaden the scope of the operations to cover the majority of green stripes along local roads. To further improve the processes, Kněžice would need to successfully secure new machinery, a reach mower with suction, and possibly also additional pre-treatment technology at the biogas plant.
Author: Jan Doležal