News / 3.3.2020

Helen speeds up coal substitution

As a step towards a carbon-neutral future, Helen is building a bioenergy heating plant in Vuosaari, which will utilise unique energy efficiency and reuse the waste heat from flue gases in an unprecedented way. Bringing the commissioning of the bioenergy plant forward by a year permits partial discontinuation of coal use even sooner than expected. The investment is estimated to have no impact on the price of district heating.

Helen's target is carbon neutrality by 2035, with coal being phased out even sooner. The Hanasaari power plant will close by the end of 2024, and its heat production will be replaced with heat recycling with heat pumps, energy storage, and the bioenergy heating plant to be built in Vuosaari, on which the investment decision has now been made. The bioenergy plant will be necessary to secure Helsinki's heat requirement also in the cold winter months. At Salmisaari, coal will be replaced by 2029.
Construction of the Vuosaari bioenergy heating plant will start this spring with the earth works, the actual building work getting under way in the autumn 2020. The aim is to have the heating plant in production use for the heating season 2022–2023, about a year sooner than anticipated.
“Bringing forward the commissioning of the bioenergy heating plant permits the deployment of the Hanasaari cogeneration plant for reserve use before the planned closure, as early as during 2023. Replacement of the Hanasaari heat production will still require biofuels, in order to secure availability of heat also in the cold winter season. We are seeking other solutions for Salmisaari,” says Pekka Manninen, CEO at Helen.  
Helen continues to invest in large-scale energy recycling using heat pumps, as well as planning projects on heat storage. Other areas under investigation include utilising geothermal heat and, in slightly longer term, ideas like modular small-scale nuclear reactors. At Salmisaari, the primary target is to substitute coal with solutions that are not based on combustion.


The new bioenergy heating plant will be built for maximum flexibility, with a view to solutions of the future. The design and capacity of the plant takes account in a number of ways of options like using different fuel fractions. The further development of the Vuosaari energy production area is also taken into account in the heat distribution connections.  
The principal fuel used in the bioenergy heating plant is forest chips created as a forestry by-product, which has no other uses. The procured fuel is certified for sustainability or its source is controlled in some other way.   The bioenergy heating plant achieves its energy efficiency by utilising a flue gas heat recovery plant and absorption heat pumps.  
“After the combustion process, the flue gases are piped to the heat recovery plant and then on to separate absorption heat pumps. This way, we are able to utilise the fuel as effectively as possible, and the double heat recovery ensures that the flue gas entering the chimney is only 10-20 degrees,” explains Project Director Antti Saikkonen from Helen.

  • Helen has set the target of carbon neutrality by 2035.
  • Helen will phase out the use of coal gradually. The Hanasaari power plant will be closed by the end of 2024, but it may be assigned for reserve use before then, depending on the commissioning schedule of the Vuosaari bioenergy heating plant. Salmisaari will be retained as an energy production area with the intention of replacing coal with solutions that are not based on combustion. As for Salmisaari, the investment decisions have not yet been finalised.
  • Replacement production has already been completed or is under construction, with investments made particularly in heat pumps: an entirely new heating and cooling plant was commissioned beneath the Esplanade Park in the summer of 2018, the Katri Vala heating and cooling plant is being extended, and a new heat pump utilising heat from sea water is under construction in Vuosaari.
  • Investments are also being made in heat storage: the old oil caves in Mustikkamaa are currently being converted into an underground heat store.   
  • The Vuosaari bioenergy heating plant is necessary to secure Helsinki's heating requirement also in the cold winter months.
  • The planned capacity of the Vuosaari bioenergy plant is 260 MW. The main fuel is forest chips.
  • The share of the bioenergy heating plant of Helen's fuel consumption is about 15%.
  • The investment value of the project is approx. EUR 260 million.
  • Deployment of the bioenergy plant in district heat production is not estimated to affect the price of district heating.