Determining national greenhouse gas emissions from waste-to-energy using the Balance Method

Different directives of the European Union require operators of waste-to-energy (WTE) plants to report the amount of electricity that is produced from biomass in the waste feed, as well as the amount of fossil CO2 emissions generated by the combustion of fossil waste materials. This paper describes the application of the Balance Method for determining the overall amount of fossil and thus climate relevant CO2 emissions from waste incineration in Austria. The results of 10 Austrian WTE plants (annual waste throughput of around 2,300 kt) demonstrate large seasonal variations in the specific fossil CO2 emissions of the plants as well as large differences between the facilities (annual means range from 32 ± 2 to 51 ± 3 kg CO2,foss/GJ heating value). An overall amount of around 924 kt/yr of fossil CO2 for all 10 WTE plants is determined. In comparison biogenic (climate neutral) CO2 emissions amount to 1,187 kt/yr, which corresponds to 56% of the total CO2 emissions from waste incineration. The total energy input via waste feed to the 10 facilities is about 22,500 TJ/yr, of which around 48% can be assigned to biogenic and thus renewable sources.