Study of differences in plant data between the Energy Statistics and the EU Emission Trading Scheme

In Sweden, about 700 plants are included in the European Union Emission Trading Scheme (ETS) for carbon dioxide (CO2), which was launched on the 1st of January 2005. The Swedish Environmental Protection Agency (EPA) is responsible for collecting and reviewing the data.

For reporting of emissions to the UNFCCC, EU Monitoring Mechanism, CLRTAP and the EU NEC Directive 1990-2005, activity data is mainly based on energy statistics from Statistics Sweden’s quarterly fuel surveys (QS) and the industrial energy survey. In some cases, additional data sources, such as companies’ environmental reports or direct information from the companies, are used as a complement.

In 2006, a study was performed by SMED to verify plant specific data from the quarterly fuels statistics with data from the ETS. One recommendation in the study was to carry out an in-depth study focussing on a few plants with large differences between their QS and ETS data , which has now been carried out and the results are presented in this report. 

In this study the fossil energy amounts from 19 plants have been calculated in the ETS and compared with the energy amounts in the QS. Where differences were found the reasons were analysed comparing the levels of energy and fuel consumption by fuel type. Contacts have been made with a few plants to better understand the differences. Waste combustion is not included in the ETS and results show that the coherence is relatively good after waste combustion was excluded from the QS. 

The QS and the emission estimations that are made based on those data have a number of deficiencies. First of all, the reported fuel amount differs slightly between the data sets and since ETS data are verified, they are likely to be more correct. Besides, on plant level, the national thermal values and emission factors that are used for the GHG inventory is not totally correct. An other deficiency in the QS is that unconventional fuels are grouped in the QS into for instance ”Other not specified fuels”. The emission factors of these fuels are associated with very large uncertainties, since they are not specific for the current fuel and plant. Finally, another problem is that some of those unconventional fuels are incorrectly classified. In the ETS some of these fuels are often partly biogenic and should hence be classified as ”Other biomass”. 

The deficiencies identified should be considered to be revised if a better coherence between the QS and the ETS is desired.