Tekniska verken in Linköping deliver, among other things, electricity, water, district heating, district cooling, waste management, biogas and efficient energy solutions. The company is wholly owned by Linköping municipality and the vision is to, in cooperation with the customers, build the world’s most energy efficient region. An important part of that work is to take care of resources that otherwise would have been wasted, an effort that has resulted in one of the world’s most efficient energy systems.
All waste water from Linköping is transported to Tekniska verken that treat the water before it is released into nature again. The sledge that remains after the treatment is processed in large chambers. In the digestion process, biogas is produced that is converted into vehicle fuel. The digested sewage sludge that remains is highly nutritious and may be very useful for improving soil quality in the agricultural sector. Biototal, a company based in Linköping, resells the nutritious sludge to different kinds of buyers.
Linköping uses a system provided by Optibag to collect the organic waste. The households collect the organic waste in specific green bags that are automatically selected when the garbage reaches the optical sorting plant. The organic waste is used to produce biogas together with waste from several of the large slaughterhouses in the region. When the waste is broken down in the digestion chamber, a gas is produced consisting of approximately 60 percent methane and 40 percent carbon dioxide. The gas is “washed” in an upgrade plant to remove the carbon dioxide. The final product is a gas consisting of approximately 97 percent methane, which can be used as vehicle fuel. The production of biogas in Linköping has been key for Östgötatrafiken, the local public transport company, to reach its goal of 100 percent fossil free transports by 2016.
When the organic waste is digested, both biogas and bio-fertilizer is produced. All the nutrients needed by crops is cumulated in the bio-fertilizer. Since March 2015, all the bio-fertilizer produced in Tekniska Verken’s biogas plant is ecologically certified (KRAV certified). The bio-fertilizer is managed and resold by Biototal to farmers. Thanks to the production of bio-fertilizer the loop between city and farm land is closed and the flow of excessive nutrients into waterways can be decreased. The bio-fertilizer is used for growing crops with the advantage that it is effective immediately regardless of precipitation (as opposed to manufactured fertilizers).
All household waste collected in Linköping (together with waste from another 20 municipalities), is transported to Gärstadverket where the waste is burnt to produce district heating and electricity. In Sweden, more than 99 percent of all household waste is taken care of through reuse, recycling, production of electricity or biological treatment. Less than 1 percent is placed in landfills.
Tekniska verken focuses on further ways to produce renewable energy and heating. In the subsidiary Bixia, there are active efforts to increase the share of renewable energy sources such as solar, wind and water. In May 2015 a large solar power installation was inaugurated on the roof of the headquarters of Tekniska verken. Thousand solar panels were delivered by the Ljungsbro-based company PPAM Solkraft.
Tekniska verken are currently building the first Swedish large scale purification plant for drug residues in waste water. The plant will be inaugurated in 2016 and Tekniska verken will have two purification plants connected to two independent water sources. Each of these can supply the inhabitants of Linköping with high quality drinking water.