The waste-to-energy plant is environmentally friendly and efficient

Stringent emissions and efficiency requirements govern the operations of the waste-to-energy plant. The plant, which handles a maximum of 135,000 tonnes of waste each year, is the primary solution for meeting all the district heating needs of the city of Salo, as 90% of the demand can be met by energy from waste.

The WtE plant replaces fossil fuels and peat in primary energy production, thus making the generated energy even more environmentally friendly. The climate-friendly WtE plant halves emissions, as the impact of the plant is lower than that of traditional power plants running on peat, coal or oil.

Thanks to cost savings in waste handling, the WtE plant promotes the advancement of recycling. Legislative changes are also pushing an increase in recycling. Thanks to plastic recycling facilities and usage bans, for example, the proportion of fossil materials in waste fuel is diminishing, thereby reducing the WtE plant’s carbon emissions.

Emissions in line with the environmental permit

The waste-to-energy plant is equipped with a high-efficiency multiphase flue gas treatment system, which ensures that any impurities found in the flue gases being discharged into the air are well below the emission limits specified in the environmental permit.

The plant’s emissions are strictly regulated, and nine emissions components are monitored using continuous measurements. The Regional State Administrative Agency issued an environmental permit decision on 7 May 2018 for the Korvenmäki waste-to-energy plant, and the plant operates in accordance with its terms.

Read the terms of the environmental permit 2018 (in Finnish)
Review of the environmental permit 2022 (in Finnish)

Waste-to-energy plant, annual emissions in 2023 (kg)

The WtE plant emissions fall well below the limits specified in the environmental permit.

Other environmental impacts

Carbon dioxide

The plant’s carbon dioxide emissions are no more than 50,700 tonnes a year. Half of the emissions come from district heating production and the rest from power generation. District heating emissions have been halved by replacing peat, coal and oil fuels with waste. Taking into account the diminished emissions from the waste processing chain, the overall reduction is significant.

WtE plant halves district heating emissions of carbon dioxide by replacing peat, coal and oil with waste fuel.
Carbon dioxide emissions from the production of a similar amount of energy from different energy sources, calculated using Statistics Finland’s default emission factors.


Waste from Southwest Finland was previously transported over long distances to be processed elsewhere in Finland and abroad. Thanks to the Korvenmäki waste-to-energy plant, long-distance waste shipments are no longer needed. Around 20 truckloads of waste fuel are brought to Korvenmäki every weekday from the Salo and Turku regions.

Noise, odour and dust

The plant does not generate any additional odours or noise in the area. The waste is unloaded and stored indoors. Exhaust air from the waste bunker is not directly discharged outside: Poit is used as combustion air in the WtE plant’s boiler, thus effectively keeping odours contained. In the WtE plant’s downtime, the exhaust air is discharged outside via a filter. Trafficked outdoor areas are asphalted, and fuels, ashes and chemicals are handled, stored and transported such that there is no damage to the environment.

Ash produced by the plant

The plant’s boiler slag, boiler ash and fly ash are shipped for post-processing as their own separate fractions. The boiler slag is temporarily stored in an intermediate storage facility, from which it is collected for post-processing. Then, metals are extracted from it and sent for reuse. The mineral matter contained in the slag can be utilised for instance in earthwork. Around 99% of the furnace slag is repurposed. The boiler ash and fly ash from flue gas treatment are neutralised and properly disposed of.