Large combustion plants are responsible for a significant proportion of anthropogenic pollutant emissions. Since 2004, emissions from large combustion plants in the 28 EU Member States have decreased, by 86 % for sulphur dioxide, 59 % for nitrogen oxides and 84 % for dust.
In 2017, from a total of 3 664 large combustion plants, 50 % of all emissions came from just 68, 141 and 58 plants for sulphur dioxide, nitrogen oxides and dust, respectively. However, the performances of these largest plants have improved greatly over time.
One indicator of the environmental performance of large combustion plants is the ratio between emissions and fuel consumption (i.e. the implied emission factor). The implied emission factors for all three pollutants decreased significantly between 2004 and 2017 for all sizes of large combustion plants.
Large combustion plants (LCPs) have been regulated in the EU through:
- the LCP Directive (Directive 2001/80/EC; fully repealed by the Industrial Emissions Directive (IED) (2010/75/EU) by 1 January 2016), which imposed minimum requirements for emissions of nitrogen oxides (NOx), sulphur dioxide (SO2) and dust;
- the Integrated Pollution Prevention and Control (IPPC) Directive (Directive 2008/1/EC; repealed by the IED (2010/75/EU) by 7 January 2013) and the related Reference Document on Best Available Techniques (BREF) for Large Combustion Plants (updated in 2017); the IPPC Directive required the establishment of integrated permits taking into account the principle of best available techniques (BATs) and local considerations;
- the IED, Directive 2010/75/EU (see Indicator specification and metadata for details); from 7 January 2013, minimum requirements have been set by this directive for new LCPs and as from 2016 for all LCPs.
The collective aim of these policies was to reduce the environmental impacts of LCPs and in particular the emissions of acidifying pollutants, particulate matter and ozone precursors, to which NOx, SO2 and dust contribute.
Emission reductions occur not only as a result of implementing policies, but also because of other factors including broader economic and societal changes, e.g. economic conditions, international fuel prices and industry initiatives.
LCPs vary significantly in size. Four capacity classes have been established for this indicator:
- small LCPs, with a thermal input of between 50 and 100 megawatts thermal (MWth);
- medium-sized LCPs, with a thermal input of between 101 and 300 MWth;
- large LCPs, with a thermal input of between 301 and 500 MWth;
- very large LCPs, with a thermal input greater than 500 MWth.
Large combustion plant emissions
Emissions from LCPs constitute a significant proportion of total anthropogenic emissions.
Between 2004 and 2017, emissions of SO2 from LCPs reduced by 86 %, NOx by 59 % and dust by 84 % (Fig. 2). Emissions have decreased for LCPs in all capacity classes; however, the majority of emission reductions in absolute terms has been achieved through environmental improvements in very large LCPs, with a rated thermal input above 500 MW (21 % of all LCPs by number, representing 70 % of the installed capacity).
Between 2007 and 2009, emissions of SO2, NOx and dust declined very significantly. Although the entry into force (on 1 January 2008) of emission limit values for existing plants under the LCP Directive occurred in this period, a potentially more significant factor was the general economic downturn in Europe that commenced during 2008. A corresponding decrease in fuel consumption between 2007 and 2009 (9 %) suggests that the decrease in emissions may have been due to a decrease in the activity of LCPs, rather than to a substantial improvement in environmental performance. This significant reduction in emissions was followed by a period of more stable but nonetheless decreasing emissions until 2017.
Very large LCPs account for only 21 % of all LCPs but are responsible for the vast majority of LCP SO2, NOx and dust emissions. In 2017, these largest plants emitted 71 % of all LCP SO2 emissions, 64 % of NOx emissions and 67 % of dust emissions.
In fact, only a small number of very large LCPs are responsible for the majority of emissions. In 2017, from a total of 3 664 LCPs, 50 % of all emissions came from just 68, 141 and 58 plants for SO2, NOx and dust, respectively. Conversely, the 1 216 smallest LCPs emitted only 5 % of SO2, 7 % of NOx and 8 % of dust.
Source – European Environment Agency