CHP plants are highly efficient, using up to 90% of the fuel’s primary energy. This results in a significant reduction in CO2 and other hazardous emissions, compared to separate production of electricity and heat. The volume of waste heat discharged into the environment is also smaller. CHP production is based on fuel combustion, and its main environmental impacts are related to flue-gas emissions and by-products, such as ash.
Replacing fossil fuels with renewable fuels reduces the environmental impact of CHP production. Renewable fuels are carbon neutral and, in most cases, their combustion results in clearly lower sulphur emissions. Nitrogen oxides are also reduced with advanced incineration technology, and other emissions can be decreased with various types of flue gas cleaning technologies. Most of our power plants and heat boilers operating in the EU countries meet the BAT (Best Available Technology) requirements in accordance with the Industrial Emissions Directive.
A by-product of solid fuel combustion is ash; up to 50% of the ash in Europe is utilised by the construction material industry, in earthworks and for filling up mines. Whatever remains is disposed of at landfills. All ash from our Russian plants is pumped as a wet slurry to ash ponds. So far, there is no utilisation option for ash slurry.
CHP production normally has only minor impacts on waterways. Cooling water is used only temporarily in connection with possible auxiliary condensing. Wastewaters are processed in the power plant's wastewater treatment system before being discharged into the environment or into the municipal sewage system.