News / 2.3.2023

New air-to-water heat pump plant for Helen’s Salmisaari power plant area

Helen is building a new industrial-scale air-to-water heat pump plant in the Salmisaari power plant area. The plant will produce renewable district heat and district cooling. The total value of the investment is EUR 13.5 million, and it has been granted almost EUR 2.6 million of energy investment aid by the Ministry of Economic Affairs and Employment.

The Salmisaari air-to-water heat pump plant will use outdoor air as a source of energy, and it will be capable of producing district heat from outdoor air even with a temperature of 8°C below freezing. In addition, in the summer season the heat pumps will be utilised in the production of district cooling. Production is scheduled to start in early 2025.

“Investments into a diverse production structure will boost our energy self-sufficiency at the same time as we continue to implement the green transition towards carbon-neutral energy production. With the heat pumps, we will achieve cost savings in district heat production and increase the district cooling capacity. Air-to-water heat pumps enable the use of the readily available, inexhaustible heat source, outdoor air, in the production of district heat production. With the pumps, we will produce heat and cooling in an energy-efficient way in the same process,” sums up Juhani Aaltonen, Head of Sustainable Energy Solutions at Helen.


The industrial-scale air-to-water heat pumps are a new technology in the Finnish conditions and, upon completion, the new Salmisaari plant will be among the first sites of similar scale built in Finland. The district heat output of the plant’s heat pumps will be 14 megawatts and its cooling output 8 megawatts. In practice, they will produce about 61 gigawatt-hours of district heat and 10 gigawatt-hours of district cooling per year.

Helen’s target is to be a carbon neutral energy company by year 2030. We are building a sustainable energy system, in which we recover heat from several different sources: from the earth, air and water. We are implementing the carbon-neutral transition together with our customers and partners by utilising artificial intelligence, data that steers consumption, the smart grid, waste heat, and renewable energy sources.

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