Progress in reducing pollution from large combustion plants (Signal)

Figure 1. SO₂ IEF 2004 and 2022 in the EU-27

Notes: IEF: Implied emission factor. It shows the emissions intensity expressed as tonnes of emissions by TJ of energy input.

Source: Compiled from EEA, 2020, 2024a.

Assessment

Large combustion plants (LCPs) have been a main source of air pollution, especially of sulphur dioxide (SO₂), nitrogen oxides (NO_X) and dust but also heavy metals, including mercury. They have been and still are a significant source of greenhouse gases (GHG). Secondary pollutants like ground-level ozone (O₃) and secondary particulate matter are also formed due to primary air pollutants being released from these plants (EEA, 2019).

What are LCPs?

LCPs are industrial facilities that burn fossil fuels or biomass to produce energy, typically in the form of electricity, heat or both. These plants are commonly found in — for example — power stations, chemical facilities, steelworks or refineries where energy-intensive operations are required. Under the Industrial Emissions Directive (IED), combustion plants are defined as ‘any technical apparatus in which fuels are [combusted] to use the heat […] generated’. Specifically, LCPs are ‘combustion plants with a total rated thermal input of 50 megawatts or more’. As of 2022, there are 3,139 LCP plants in the EU (EEA, 2024a; EU, 2024).

Frederic Weber, ZeroWaste PIX EEA

Background

Since the 1980s, the EU has been developing policies to tackle acidification and transboundary air pollution, using an EU-wide framework coherent with the internal energy market (EEA, 2019). As part of that, the first LCP Directive (LCPD I, 88/609/EEC) was introduced in 1988 to regulate SO₂, NO_X and dust emissions.

In the 1990s, critical loads for acidification of ecosystems were exceeded in more than 10% of the EU’s total area (back then, the EU was comprised of only 15 Member States). Industry was responsible for over 90% of all SO₂ and 35% of all NO_X emissions across the EU , which together with ammonia are the three main pollutants contributing to acidification (EC, 1997; EEA, 2019).

In 2001, the LCP Directive was revised with stricter limits (LCPD II, 2001/80/EC) (EU, 1988, 2001). This sector-specific legislation was replaced in 2010 by a more integrated directive – The Industrial Emissions Directive (IED, 2010/75/EU, as amended by Directive 2024/1785) — that sets out an environmental permitting framework based on the use of best available techniques (BAT). This EU law covers not only LCPs but many other highly polluting industrial sectors such as chemical plants, waste management installations and paper mills (EU, 2010, 2024).

The current and former regulation applying to LCPs have obligated Member States to report information on crucial aspects for these plants since 2004, including their rated thermal input; annual emissions of SO₂, NO_X and dust; operating hours; and annual energy input of a variety of fuel types. The reporting obligations increased in detail over time as the regulation was strengthened.

How SO₂ emissions dropped over the last 20 years

One of the best pieces of evidence proving that EU legislation targeting LCPs has been effective is the evolution of the average SO₂ implied emission factor (emissions by unit of energy input, abbreviated as IEF) from all LCPs reported by the EU-27. As can be seen in Figure 1, all EU Member States reduced their SO₂ IEF between 2004 and 2022. This is related to improved abatement technologies coupled with the decreasing use of coal in the sector, which has been replaced by natural gas and renewable energy sources. Environmental and climate legislation played a significant role in spurring these changes, while other factors such as economic aspects also played a part. In 2004 the relative performance of countries varied significantly, but now all countries perform at very similar levels, including the newest EU Member States joining in 2004, 2007 and 2013. This is not only an environment success story but also a Single Market reinforcement, as differential abatement efforts and fuel shifts were a significant issue in terms of level playing field (EU, 1996, 2001, 2019; EP, 2024).  

Today’s challenges

Although they have improved their environmental performance over the last twenty years, the EU still faces challenges from LCP emissions, especially in central and eastern Europe where solid fuels such as coal and biomass are still widely used in households and power plants (EEA, 2024b; 2024c). The long-term use of coal has also had consequences on European waters. For instance, long-lived pollutants such as mercury are responsible for the lack of improvement in the chemical status of European surface waters (EEA, 2024d). Map 1 below shows the top 100 power plants with the highest damage costs in the EU caused by the main air pollutants in 2021. The ranking is led by some of the biggest thermal power plants in Europe, many of which burn coal and lignite.

Map 1. Top 100 power plants representing the highest aggregated damage costs from main air pollutants, 2021

Note: At the time of the assessment, Czechia, Slovakia, Lithuania and Malta had not submitted 2021 data Source: EEA, 2024b

To achieve its zero-pollution ambition by 2050 (EC, 2021), the EU cannot rely solely on traditional end-of-pipe and sector-by-sector approaches. Emerging technologies and tackling the problem from a systems perspective will be key for decarbonising and reducing the impact of Europe’s energy sector. The latest rules coming into force due to the recently revised IED (published in July 2024) are a significant step in this direction. Firstly, emission limit values based on BAT will be stricter. In tandem, measures strengthening innovation and the circular economy will have more influence over the conditions LCPs and other large industrial plants will need to meet to obtain permits. This transition to a cleaner power sector will enable society to better face the challenges of high fuel prices, climate change-related events such as floods or water scarcity, dependencies on critical raw materials, the availability of affordable renewable energy sources and fierce competition from large industrial operators inside and outside of the EU.

Previously, the IED included derogation schemes allowing certain LCPs to temporarily comply with less strict emission limits than required by the IED and the BAT conclusions for LCP (EU, 2010, 2021). In 2024, these old derogation schemes expired; the LCPs previously covered by such schemes are required to have either closed or upgraded to comply with the IED and BAT requirements. This evolution is expected to result in further emission reductions.

In 2024, the Commission began assessing how around 100 of the EU’s most polluting LCPs, previously covered under one of the derogation schemes, comply with the IED and BAT requirements. The assessment will continue into 2025 and a study documenting the findings will be published the same year. This assessment used a new viewer with LCP data which presents the it in a more accesible way and helps analyse trends on various parameters (LCP Tool). This helps the Commission investigate the evolution in compliance of the most polluting LCPs with stricter requirements, which is expected to result in further emission reductions.

Satellite data to validate LCP emissions

Data from LCPs have been reported by Member States for the last 20 years. Technological advances have the potential to help validate it as well as fill data gaps. The EEA and the European Topic Centre on Data Integration and Digitalisation have been working on a pilot project to evaluate the potential of satellite imagery as a way to estimate NO_X emissions from LCPs. The results are promising but there is significant room for improvement: background pollution and meteorological events still jeopardise the calculations to a high degree and availability of sufficient satellite runs is a limitation. Map 2 shows the results of these calculations for 2021 for 36 of the plants covered by Map 1, comparing the reported emissions with those calculated with satellite data.

Map 2. 36 LCPs from the top 100 with the highest aggregated damage costs, for which NOx emissions could be calculated based on satellite data, 2021

Note: Compiled using data from the Copernicus Sentinel-5P/ TROPOspheric Monitoring Instrument (TROPOMI) complemented with the Copernicus Atmosphere Monitoring Service (CAMS). Source: EEA, 2024b; ETC-DI, 2023.

Please consult the relevant indicators and signals below for a more comprehensive overview on the topic.

Other relevant indicators and signals

Industrial pollutant releases into the air in Europe (Indicator)

Persistent organic pollutant emissions in Europe (Indicator)

Emissions of major pollutants into the air by extractive industries (Indicator)

References