Stockholm Exergi, a joint venture between Finnish utility Fortum and the city of Stockholm, is exploring the possibility of making the Swedish capital’s district heating the world’s first to become carbon negative.
As a first step, the company this spring will close its last coal-fired boiler for power and heat production at the Värtaverket combined-cycle plant in Stockholm.
Stockholm Exergi already in 2016 had replaced most of Värtaverket’s coal-based production with biofuels.
The company is now investigating whether a carbon capture system (CCS) could be utilized at Värtaverket, which would turn the plant carbon negative. Based on the pilot in progress, bio-CCS is also a cost-effective alternative for reducing carbon dioxide emissions, the company claims.
The captured carbon dioxide can be stored permanently, for example, in seabed rock formations, utilised in industrial processes or even used in greenhouses.
Stockholm Exergi has more than 800,000 heating customers. In addition, its district cooling is utilized in over 400 hospitals, data centers and companies. The joint venture’s targets to use 100% renewable fuels by 2022.
The CCS plans at biofuel-powered district heating are part of Stockholm’s target to become the first city in the world with a positive carbon footprint by 2040.
Fortum is also testing CCS technology in Oslo at its joint venture Fortum Oslo Varme. Both the Stockholm and Oslo projects are partnering with the Northern Lights initiative, which is studying carbon storage in the bedrock of the North Sea.
To get the CO2 to the North Sea from Stockholm, it would be liquefied, and the fluid shipped to Bergen, Norway, a Fortum press official told Recharge. Heat generated during that process is also slated to be used in district heating.
Stockholm’s climate plans show how crucial public policy is to prompt companies to become climate-friendly.
Fortum is not the climate-friendly poster child everywhere.
The Helsinki-based utility with €5.2bn in sales in 2018 says in that year 57% of its power generation was CO2-free. But the company in the same year had bought close to half of fossil generation spin-off Uniper from German utility E.ON, which has a vast fossil generation fleet in Germany and Russia.
Uniper recently has been under attack by climate activist in Germany for its plan to still take the Datteln 4 coal-fired plan online this summer. It would be the last new coal-fired plant to enter service in Europe’s largest economy after a decision to phase out coal and lignite by 2038.
Uniper argues taking the coal-fired plant online is actually part of its plan to cut emissions, as the modern plant can be quickly ramped up and down depending on the share of renewables in the Germany’s power grid.