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 2019, our sulphur dioxide and nitrogen oxide emissions decreased by about 10 per cent on the previous year. The fall in emissions is due to the efficient operation of the cleaning equipment and the increased use of low-sulphur fuels.

Acidifying emissions


  Sulphur dioxide Nitrogen oxides
2015 1600 3600
2016 2700 3600
2017 2200 3600
2018 2100 3600
2019 2000 3300



  Sulphur dioxide Nitrogen oxidies
2015 130 280
2016 220 280
2017 170 280
2018 160 260
2019 150 250

Particulate emissions were down by about 50 per cent compared with the previous year thanks to the efficient flue gas cleaning system and the low number of fault situations.

Particulate emissions


2015 72
2016 110
2017 100
2018 86
2019 55



2015 6.2
2016 9.8
2017 8.6
2018 7.2
2019 4.2

In 2019, our emissions were below the limit values at all our plants.  

We are constantly making changes in order to reach the tightening emission limit values. In 2019, the Lassila heating plant started using only light fuel oil. In addition, the burners of the natural gas boilers of the plant were changed to low-NOx burners. As a result of these changes, the emissions continue to fall.  

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 2019, we produced a total of 114,000 tonnes of by-products (114,000 tonnes in 2018). Utilisation of by-products in landfill structures continued. On the other hand, the earth construction use of bottom ash decreased although we managed to unload some of the intermediate storage of bottom ash, for which reason the utilisation rate of by-products fell to 94 per cent (2018: 97 per cent).

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.

Utilisation of by-products, tonnes

  Intermediate storage Disposal Utilisation
2015 5000 14700 50000
2016 9400 31400 75100
2017 10500 600 108200
2018 1000 2000 110700
2019 10286 11000 107446


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 2019, we produced 9,113 tonnes of waste (2018: 4,780 tonnes), 58 per cent of which was utilised as material and 6 cent as energy (2018: 77 per cent and 10 per cent).  The amount of waste increased especially in worksites. The amount of waste taken to the landfill (e.g. rock aggregates and soil) was higher than in the previous years. The amount of dangerous substances produced was slightly up compared with last year.

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

  Hazardous waste Landfill Utilisation as energy Utilisation as material
2015 240 1270 170 950
2016 450 1030 60 6800
2017 240 360 380 4610
2018 450 130 490 3710
2019 539 2746 514 5314


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 2019, a total of 147 gigawatt-hours of waste heat and cooling energy from power plants and cooling centres was released into the sea. This is 1.2 per cent of the used fuel energy (2018: 126 gigawatt-hours or 1.0 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 2019.

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