The district heating will be delivered after the trial. Photo by Laura Vanzo/Visit Tampere

The district heating will be delivered after the trial. Photo by Laura Vanzo/Visit Tampere

Tampere Electric Company (Tampereen Sähkölaitos Oy) is to deliver carbon-negative district heating to its customers in the Hiedanranta city district of Tampere via its district heating network.

This will be the first occasion that carbon-negative district heating is being produced commercially in Finland, and the utility is purchasing the heating from Carbofex Oy company, which will produce the district heating alongside biochar, its main product. Hiedanranta will act as a development platform in the project.

Carbon-negative equals climate positive

Carbon-negative sometimes referred to as “climate positive” goes a step beyond the measures taken to be carbon neutral (ie net zero carbon emissions) and means more carbon dioxide is being removed from the atmosphere than is being produced. Meanwhile, district heating networks are regarded as one of the most energy-saving ways of heating homes in densely populated areas.

The Carbofex factory heats up wood from the Tampere region and turns it into a mineral, in this case biochar. This happens through pyrolysis. When biochar is used as a soil amendment, for example in landscaping work, it will sequester (isolate) carbon permanently in the soil. The production process also produces waste heat, which will be used for district heating.

According to Tampereen Sähkölaitos, the Hiedanranta solution continues the process of opening up its district heating network which began two years ago when a housing company in the city started selling its excess heat to be used in the heating network.

"The aim is to create a new district that is smart and sustainable together with innovative developers”

“In Hiedanranta, we are testing and developing new smart solutions,” said Reijo Väliharju, project development director at Tampere. “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.”

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 trialling of the Carbofex heat recovery steam generator is underway and delivery of carbon-negative district heating to customers will begin during this autumn once the trial is complete.

Meeting annual heating needs

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.

“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,” added Jukka Joronen, vice president, energy markets at Tampereen Sähkölaitos.

“When several producers can produce energy for the district heating network, it helps to ensure a competitive and stable price for district heating.”

In one year, the Carbofex plant will reportedly capture up to 2,500 tonnes of carbon, as every kilogram of biochar produced will sequester around 3.5kg 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.

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 as well as the city’s own development departments like the Smart Tampere smart city programme.

If you like this, you might be interested in reading the following:

Tampere shares recipes for smart city success

The book defines the key elements for a smart city programme and offers guidance on their implementation

Read more

Smart Tampere refocuses its efforts

It says actions and activity linked to the project will be better distributed between different city departments

Read more

How Tampere aims to be top for smart mobility testing

Backbone of the Finnish city’s smart public transportation system is a tramway running through the city by 2021

Read more