A combustion plant is a technical apparatus in which fuel is oxidised to use the heat generated. Large Combustion Plants (LCPs) have a total rated thermal input equal to or greater than 50 MW, irrespective of the type of fuel used. There has been considerable progress in reducing their pollutant emissions in the EU as shown in the graph below and others at the EEA indicators page. Nevertheless, in 2015, LCPs accounted respectively for 44 % and 14 % of EU-28 total emissions of sulphur dioxide (SO2) and nitrogen oxides (NOX) to air.
Since they account for such a significant share of total pollutant emissions to air, the IED contains specific provisions for them. A recent study assessed the contribution of EU legislation and other factors to the reductions in LCP pollutant emissions between 2004 and 2015. This concluded that of the observed reductions in pollutant emissions, 71% of SO2, 38% of NOX and 75% of dust were due to changes in the emission factors, which were largely due to EU legislation.
Chapter III and Annex V of the IED set the minimum requirements for certain pollutant emissions from LCPs. These provisions replaced the LCP Directive (2001/80/EC).
The minimum requirements apply without prejudice to the provisions of Chapter II of the IED. In line with these requirements, permits for LCPs need to be updated in line with the LCP BAT conclusions by August 2021. These BAT conclusions establish performance levels associated with BAT and include monitoring requirements.
1. Aggregation rules
In cases where the waste gases of two or more combustion plants are, or could be, discharged through a common stack, the aggregation rules of Article 29 of the IED define whether and when such a combination of plants shall be considered as a single combustion plant. For the purpose of calculating the total rated thermal input, combustion plants with a rated thermal input below 15 MW shall not be considered. More information is provided in the questions answered on CIRCABC.
2. Emission limit values
Until their permits are updated in line with the LCP BAT conclusions, LCP emission limit values are set out in Annex V to the IED. The applicable values are determined in relation to the total rated thermal input of the entire combustion plant.
Where an LCP is extended or changed, the emission limit values in Part 2 of Annex V (in relation to the total rated thermal input of the entire LCP) apply to the part of the plant affected by the change.
LCPs firing indigenous solid fuel may not be able to comply with the SO2 emission limit values set in Annex V due to the fuel characteristics. They may instead apply a minimum rates of desulphurisation set out in Part 5 of Annex V, subject to prior validation by the competent authority of a technical report with a justification.
In the case of a multi-fuel firing combustion plant, the emission limit values shall be set in accordance with Article 40 of the IED or, where applicable, Part 7 of Annex V.
3. Monitoring and compliance assessment
Monitoring of air polluting substances must be carried out in accordance with the provisions of Part 3 of IED Annex V. The IED emission limit values to air shall be regarded as being complied with if the conditions set out in Part 4 of Annex V are fulfilled.
EU emission inventories for LCPs have been established since the 2004 reporting year. The Commission published a summary of these inventories covering each three year period until the 2012 reporting year.
From the 2013 reporting year, Member States are required to report annually on the energy input and sulphur dioxide, nitrogen oxides and dust emissions of all LCPs. The following links provide access to this data and indicators derived from it:
Information on annual emissions from large combustion plants and other industrial sources is also available through the European Pollutant Release and Transfer Register (E-PRTR).
Four mechanisms allow temporary exemptions from the emission limit values set in Annex V for some LCPs meeting the specified conditions. In no case can the resulting emission limit values be weaker than in their permits on 31 December 2015.
1. Transitional National Plan (Article 32)
2. Limited life time derogation (Article 33)
3. Small isolated systems (Article 34)
4. District heating plants (Article 35)