Environmental impacts

Flue gas emissions from energy production constitute our most significant environmental impact.

ympäristövaikutukset 2019

We aim to keep the emissions of our power plants having an impact on air quality, i.e. sulphur dioxide, nitrogen oxide and particulate emissions, within the constantly tightening limit values specified by the authorities.  

In 2020, our sulphur dioxide and nitrogen oxide emissions decreased by about 30 per cent on the previous year. As a result of the new environmental legislation, the limit values of power plant emissions having an impact on air quality have been tightened. We have invested in technology and a mode of driving that reduce emissions. Efficient operation of cleaning devices and the increased use of natural gas also had an impact on the reduction of emissions.

Acidifying emissions


  Sulphur dioxide Nitrogen oxides
2016 2700 3600
2017 2200 3600
2018 2100 3600
2019 2000 3300
2020 1400 2100



  Sulphur dioxide Nitrogen oxidies
2016 220 280
2017 170 280
2018 160 260
2019 150 250
2020 110 170

Particulate emissions 2020 at the same level as in the previous year.

Particulate emissions


2016 110
2017 100
2018 86
2019 55
2020 59



2016 9.8
2017 8.6
2018 7.2
2019 4.2
2020 5.0

The limit value of sulphur dioxide emissions was exceeded in 2020 at the daily level once in Salmisaari and twice in Hanasaari. In addition, the monthly limit value for nitrogen oxides was exceeded once in Salmisaari.  

We monitor the emissions of our power plants according to the monitoring plans approved by the authorities. An independent accredited tester ensures the quality of our measurements each year.  

* Acidifying emissions and particulate emissions mg/kWh are calculated by dividing the emissions of our energy production and co-owned production by the total energy sold. Production and distribution losses have been taken into account when calculating the amount of energy produced. In 2017, the calculation was specified by including the electricity used by heat pumps and district heat pumping in the calculation of emissions.


The by-products of energy production mainly consist of ashes and the end product created in flue gas desulphurisation. In 2020, we produced a total of 102,400 tonnes of by-products (114,000 tonnes in 2019). Utilisation of by-products in landfill structures continued. The land construction use of bottom ash picked up slightly and, as a result, we were able to unload some of the intermediate storage of bottom ash. All in all, the share of by-product utilisation remained at a good level of 93 per cent (94 per cent in 2019).

We aim to utilise by-products as efficiently as possible. By-products are used, e.g. in cement manufacture and earth construction. Utilisation of by-products reduces the use of pristine mineral aggregate and soil.

N.B. A couple of corrections to the table of by-product utilisation for the year 2019. Tonne-related data is updated in the table in question.

Utilisation of by-products, tonnes

  Intermediate storage Disposal Utilisation
2015 5000 14700 50000
2016 9400 31400 75100
2017 10500 572 108200
2018 1000 2000 110700
2019 6419 11 107446
2020 7401 22 94953


Our operations also produce various types of waste. Primarily, we aim to prevent the production of waste. Any waste we produce is sorted and recycled wherever possible. We maintain waste bookkeeping and hand over waste only to transport companies that are in the waste management register and to recipients entitled to receive the waste in question.  

In 2020, we produced 14,373 tonnes of waste (9,113 tonnes in 2019), 93 per cent of which was utilised as material and 3.7 per cent as energy (58 and 5.6 per cent in 2019). The amount of waste increased especially in network and work sites. The amount of waste taken to the landfill was smaller than in the previous years. There were also fewer hazardous substances produced than in the previous year.

Utilisation of waste produced in Helen’s Ltd and, from 2016, in the energy network areas, tonnes

  Hazardous waste Landfill Utilisation as energy Utilisation as material
2016 450 1030 60 6800
2017 240 360 380 4610
2018 450 130 490 3710
2019 539 2746 514 5314
2020 367 97 534 13376


The majority of the heat we produce is utilised as district heat, which considerably diminishes the volume of heat conducted into the sea and, that way, the impacts on watercourses. We also utilise the heat of purified waste water in the Katri Vala heating and cooling plant, which reduces the volume of waste heat ending up in the sea.  

In 2020, a total of 169 gigawatt-hours of waste heat and cooling energy from power plants and cooling centres was released into the sea. This is 1.6 per cent of the used fuel energy (2019: 147 gigawatt-hours or 1.2 per cent). Since year 2000, the annual load has varied between 120 and 2,200 gigawatt-hours.

The principal impacts of our energy production on watercourses are the result of conducting cooling water, i.e. warmed-up sea water, into the sea. When studying the impacts of power plants on watercourses, no eutrophication impacts have been detected. Eutrophication in the Helsinki sea areas is caused by other loading, basically by waste waters from households and by scattered loading.  

In addition to cooling waters, small amounts of waste and washing waters from power plants, as well as neutralised washing waters from wastewater treatment plants and laboratories, are conducted into the sea. The flow rate, temperature, temperature rise, acidity and hydrocarbon, i.e. oil contents, of the waters conducted into the sea are monitored and reported to the authorities. The entry of oil into the waterways is prevented with oil separation pools equipped with alarm systems.


There were no environmental deviations in 2020.

See also

Environmental responsibility

Reduction of environmental impacts is an important part of our activities. Our long-term goal is climate-neutral energy production.

Carbon-Neutral Energy

Climate impacts

Origin and sustainability of energy