The commercial production of carbon-negative district heating has begun in Hiedanranta, Tampere. This is the first time carbon-negative district heating is being produced commercially in Finland. Hiedanranta city district in Tampere will act as a development platform in a project where Carbofex Oy company will produce district heating alongside biochar, its main product. The district heating will be bought by Tampereen Sähkölaitos Oy (Tampere electric company), which will distribute it to its own customers via its district heating network. The Hiedanranta Development Project by the City of Tampere has assisted the cooperation efforts and will become the first customer of the carbon-negative district heating production.
The Carbofex factory heats up wood from the Tampere Region and turns it into a mineral, i.e. biochar. This happens through pyrolysis. When biochar is used as a soil amendment, for example in landscaping work, it will sequester carbon permanently in the soil. The production process also produces waste heat, which will be used for district heating.
During the production of biochar, 50% of the carbon in the wood being used will be sequestered into a form from which it will not be released back into circulation. Pyrolysis releases pyrolysis gas and oil, of which 30% will be used as energy for the process, and the remaining 70% can be used for producing district heating. The result is a carbon-negative overall process, as the amount of carbon sequestered exceeds the emissions produced.
For Tampereen Sähkölaitos (Tampere electric company), the Hiedanranta solution continues the process of opening up the district heating network: two years ago, a housing company in Tampere started selling its excess heat to be used in the Sähkölaitos’s district heating network.
– “Buying district heating from Carbofex supports Tampereen Sähkölaitos’s aims of energy network openness, of being a pioneer and of using solutions that are sustainable from a climate perspective. When several producers can produce energy for the district heating network, it helps to ensure a competitive and stable price for district heating,” says Jukka Joronen, Vice President, Energy markets at Tampereen Sähkölaitos Oy.
Heating for around 30 multi-storey blocks
Tampereen Sähkölaitos started building the district heating network in Hiedanranta last spring, and until now the heating in the area has come from power and heating plants in the nearby area. The trialing of the Carbofex heat recovery steam generator started last week (week 42). The delivery of carbon-negative district heating to customers will begin during this autumn after the trial has ended.
The district heating produced is estimated to be enough for the annual heating needs of around 30 multi-storey blocks. It will be used for the heating of Hiedanranta’s current facilities that are used for purposes such as the city’s cultural activities.
– “In Hiedanranta, we are testing and developing new smart solutions. The realisation of carbon-negative district heating is an important testament to the success of the development activities seeking cost-effective solutions for climate change. The aim is to create a new district that is smart and sustainable together with innovative developers,” says Reijo Väliharju, Project Development Director at the City of Tampere.
In a year, the Carbofex plant will capture up to 2,500 tonnes of carbon, as every kilogram of biochar produced will sequester around 3.5 kg of carbon in the soil. Biochar is also used for filtering. Urban runoff processing is one of the uses that is being planned at Hiedanranta.
Expandable and modifiable concept
The Carbofex plant is potentially the first production facility in the world to produce both biochar and carbon-negative district heating. There are no known productions of the same scale.
If the capacity at Carbofex is increased, the district heating capacity will also increase, which means that carbon-negative district heating can be distributed via the district heating network to customers in an even larger area.
– “Production is also possible in large units, and our technology can be modified for export. In addition to heat production, the technology can also be used to produce cooling or water for areas suffering from drought, as the energy being generated can be used for distilling seawater into fresh water. This means that we do have technologies for curbing climate change,” says Sampo Tukiainen, CEO at Carbofex Oy.
Hiedanranta acts as a platform for developing experiments and projects that promote smart and sustainable solutions as well as circular economy solutions. This is done in cooperation with residents, companies, research institutions, other organisations and, of course, city’s own development departments like the Smart Tampere smart city program.
– “Hiedanranta’s experimental spirit and enthusiasm for trying new things is a good fit for us. The good location and the closeness of the district heating network also influenced our location choice. We found suitable facilities at a former fire station of a factory,” says CEO Tukiainen.
In the future, Hiedanranta will form a new centre for western Tampere together with Lielahti city district. Located around four kilometres from the city centre, the new district is situated along the upcoming tramway (that will run in Tampere in 2021). Homes for 25,000 residents as well as 10,000 jobs have been planned for Hiedanranta.