Energy self-sufficient village Kněžice
In the first half of the 20th century had villagers energy required on the place where they lived and worked. They had feed for animals, good food for themselves, wood for the stove and ash back into the nature. With composted animal and plant waste replenished they nutrients for fields. Horses and stock cattle gave them a cheap and easily renewable tensile strength, independent of oil or natural gas. This, in its general scope created self-sufficiency of the region and the country.
Today, of course, is different time, but we also want to have a warm home, good quality food and the beautiful, unspoiled nature and in addition we want to put everything in line with the current trend of sustainable development.
Thoughts about all this raced through minds of local residents of a small Czech village Kněžice at Městec Králové during the annual autumn and winter smoke fallout from domestic coal boilers, among rotting piles of loose branches and grass clippings and domestic cesspools often overflowing drains into surface waters. Drainage system for Kněžice itself and its two local area (total population 508) would be complicated and costly. Then the question arose, why not to use any waste incl. biological (grass out of 5 ha of municipal areas, raked leaves, waste from households, canteens, etc.) in a biogas plant, which can replace the wastewater treatment plant and sewer system too.
Thus, the project of bioenergy centre, which consists of a biogas plant with CHP (electrical output of 330 kW / thermal output of 405 kW) and a municipal heating plant (with two boilers of 800 and 400 kW), came into being. Since 2007 technological unit for CZK 138 million supplies with heat over 90% of the village population and produces more electricity than the village can use up, which enables it to sell leftover back to the grid. So the village is in principle the first Czech energy self-sufficient municipality. Biomass heating plant uses wood chips and straw. In addition the centre, which is fully operated by the municipality, produces energetic pellets from herbal material for family houses heating in the neighbourhood. Cereal and flaxen straw, energetic sorrel stalks in huge bundles and subtle garbage for the plant are provided mainly by local farmers. Ash and the biogas station digestate are used for land fertilization.
The village has managed to get CZK 83.7 mil from the European Regional Development Fund and CZK 11.1 mil from State Environmental Fund, return of remaining CZK 43.2 mil, which it had to pay from its sources is around 15 years. (Whereas sewer system with a wastewater treatment plant would come to about CZK 45 mil. Tax policy changed too - today municipality may be a subject to VAT, so it could reduce the price by another 19%.)
"I would definitely recommend this system to other municipalities, but I would encourage them to come over to our, or a similar facility and learn from the mistakes that we have made through ignorance of the system. It is possible to use different combinations that can be model upon specific possibilities of given municipality", says the mayor Mr. Milan Kazda. "Our project definitely affected our environment. Every year we save over ten thousand tons of CO2 emissions and it shows even while walking around the village. "