News / 8.1.2016

New district heat record was set in Helsinki

A new record in the demand for district heat, 2,650 MW, was broken in Helsinki on Thursday, 7 January 2016, as a result of a long-lasting cold spell.

The latest peak in district heat was reached before noon on Thursday. The previous record from a few years ago was surpassed by a good 50 megawatts (MW). The record-breaking demand was the result of sub-zero temperatures continuing for several days: the structures of properties had cooled down, and stores and businesses were open on Thursday. The volume of buildings heated in Helsinki has also grown along with continuing construction of new buildings over the past few years.

Helen’s combined heat and power (CHP) plants in Salmisaari, Hanasaari and Vuosaari are currently producing heat and electricity at full power. The majority of peak-load and reserve heating plants located throughout the city are in operation, and one heat pump plant is producing district heat.

– The operation of the district heating network in Helsinki is secure, and the available heat production is sufficient event if the extremely low temperatures continue, promises Director Marko Riipinen of Helen Ltd.  – The large CHP plants are already in full operation, but the heating plants do have extra production capacity if we need more district heating.

District heat is stored in accumulators

Heat consumption varies not only according to the seasons but also to the time of day and night. More heat is needed during the day than at night. In the morning, heat consumption grows rapidly when the residents need hot water and the air conditioning in businesses and offices kick into normal action. Therefore, heat produced with cogeneration is stored in large water tanks, i.e. so-called heat accumulators. When the heat demand rises in the morning, extra power is transmitted from the accumulators to the district heating network. Helen’s heat accumulators are located at Vuosaari and Salmisaari, with a total power of 200 megawatts. For example, by using the Vuosaari heat accumulator, it is possible to reduce energy production on normal winter mornings with the equivalent of one heating plant. When the temperatures plummet, we meet the demand with peak-load and reserve heating plants.

Further information about energy production in Helsinki


  • District heating covers 90% of the heated volume of buildings in the entire city of Helsinki 
  • An increasing amount of district heat is produced with renewable energy sources: utilising the excess heat of purified waste water, with pellets, and with district cooling utilising solar heat 
  • Total length of Helen’s district heating network is 1,300 kilometres 
  • In Helsinki, district heat is produced in CHP plants in Hanasaari, Salmisaari and Vuosaari and in heating plants located in various parts of the city 
  • Helsinki represents about 10% of the heating need of the entire country


Disclaimer: Contact details: Communications, Helen Ltd, 00090, Helen, Telephone exchange, +358 9 6171