Emissions of SO₂, NOx and particulate matter

G4-EN21 G4-EN30

The biggest atmospheric pollutants associated with thermoelectric production are sulfur oxides (SO2), nitrogen oxides (NOx), and particulate matter.

In almost all large plants these pollutants are measured continuously through analyzers installed on stacks, while in small plants it is done periodically through analysis and measurement campaigns or by using statistical parameters.

Compared to 2014, the most significant change concerned the reduction in particulate matter, which fell by around 30% in 2015 thanks to the coming into operation of new abatement systems in some units of the Russian plant at Reftinskaya. SO2 emissions, on the other hand, rose by 10.5%, mainly due to the temporary shutdown of some units which are being repaired in the Nováky power plant in Slovakia, which entailed a greater contribution from less efficient units with higher emissions.

Specific emissions compared to total net production (g/kWh)

Specific emissions compared to total net production

NOx emissions were similar to the figure for 2014.

The specific values of emissions into the atmosphere reflect the trend in total emissions, also in relation to simple and combined thermoelectric production in reference to the production of electricity and heat. In future years a gradual reduction in pollutants is expected thanks to a series of interventions to increase efficiency at all the generation plant, including also the gradual closure of less efficient plant.

2020 Objectives

Compared to the data recorded in 2010 Enel has set itself the target of achieving new objectives by 2020, which have been revised on the basis of the results achieved and the planning for the next four years which will see a change in the mix towards renewables and a reduction in generation from fossil fuels:

  • -30% total specific emissions of sulfur oxides (SO2) (previous target -10%);
  • -30% total specific emissions of nitrogen oxides (NOx) (previous target -10%);
  • -70% total specific emissions of particulate matter (previous target -50%).




In addition Enel, as regards “minor” pollutants (such as metals including mercury), has undertaken enormous campaigns to measure concentrations in the smoke produced by thermoelectric plant – in a range of situations divided by type of fuel and abatement systems – obtaining results that comfortably comply with the precise limits established by the laws in force in the various countries where Enel operates. In particular, as regards the emissions of mercury, which are typical of electricity production from coal, in 2015 around 0.544 tons were recorded, covering just Italy and Spain which currently represent 72% of thermoelectric production from coal for the whole Group.

Mercury emissions are communicated to the competent authorities for recording in the European Pollutant Release and Transfer Register (E-PRTR) in application of EU Regulation no. 166/2006 and are subject to associated controls in terms of completeness, coherence, and credibility (article 2 of Regulation no. 166/2006).