A self-sufficient town
The initiator and investor of the whole project is the municipality of Kněžice. Most of the funding for the project came from EU financial support schemes, a smaller part consisted of a loan from the bank and from the State Environmental Fund. The investment cost of this project was CZK 117 million (around 5 million Euro), without VAT, and has 123 connection points. This project is comparable to some of the far more intense investments in the Czech energy sector.
The total investment consisted in the construction of: (i) biogas stations with a cogeneration unit; (ii) wood waste incineration plants; and (iii) heat conduit from pre-insulated pipelines around the town. The latter will transport to almost every home in the town the heating and domestic hot water, coming from the boiler room and from the biogas plant throughout the year.
The boiler room mainly burns grain, linseed straw and energy sorrel in giant packs as well as small wood waste. It then delivers heat to the central heating system (CHP). Ash from wood and straw burning is used as a fertilizer for agricultural land. The boilers are in operation only during the heating period, when the excess heat from the biogas station is not enough to cover the heat demand in the CHP system. Mainly organic waste from a local farm, livestock manure, as well as bad and old biomass (silage, grass, grain, etc.) serve as an entry to the biogas plant. The station further elaborates and ecologically eliminates the sober content of the septic tanks and cesspools from Kněžice and its surroundings.