The village of Strem in Südburgenland makes use of fallow agricultural land in the region for energy production. The process of solid-state fermentation is used to convert grass and clover together with whole maize plants into biogas. And the farmers are happy to have a new source of income. Since 2003, Strem has had a biomass heating plant with integrated district heating grid – a good starting basis for the economically feasible construction of a biogas plant. Since November 2004, “Biogas Strem Errichtungs- und Betriebs GmbH & Co KG” have been operating a biogas plant with an output of 500 kWel next to the biomass plant operated by the agricultural co-operative “Öko Energie Strem”.
Contacts with relevant manufacturers had already been established; working jointly with the Interuniversity Research Institute for Agrobiotechnology at the University of Natural Resources and Applied Life Sciences (IFA Tulln), planning work started in 2004 with the group as a new RENET competence node in order to produce electrical and thermal energy from renewable energy sources and existing resources (regenerable raw materials such as grass, clover, maize, sunflowers). The thermal energy which is produced is fed into the local district heating grid, the electrical energy is fed into the local electricity supply network at the tariff provided for under the Green Power Act. The Green Power Act promotes the generation of electrical power from renewable energy sources. For a 500 kWel biogas plant, a tariff of 14.5 cents/kWh is guaranteed for 13 years.
Due to numerous agricultural operations having had to change over from full-time operation to farming as a sideline, animal husbandry has been reduced to a minimum; with the decline of animal husbandry the meadows are no longer being used and arable land is lying fallow, which means that there is enough land available within the immediate vicinity of the biogas plant for the cultivation of regenerable raw materials, which can be grown using environmentally friendly methods of farming to provide all of the raw materials required with minimal expenditure on transportation.
The biogas plant at Strem is of particular importance for the development of biogas technology and is providing valuable results in terms of:
- start-up operation and optimisation for dry fermentation
- optimisation of process technology and reactor loading
- partial reforming of biogas to improve engine performance
- expert system for process control