Challenges for the accounting of emerging negative and zero/low emission technologies

The present paper investigates challenges for the reporting and accounting of negative emission technologies (NETs) and zero or low emission technologies (ZLETs) in GHG emissions inventories, under the EU Directive on the promotion of renewable energies (RED II) and under the EU Emissions Trading System (EU-ETS). Technology-wise we focus on NETs/ZLETs based on engineered processes setting aside natural processes and natural process enhancers.

For GHG emission inventories, there are open questions how to address the intermediate storage of carbon in E-fuels based on fossil CCU, biomass (BECCU) or atmospheric origin (DACCU): The basic options are (1) to either calculate negative emissions for the recovery or removal of CO₂ for E-fuel production or (2) not to include the emissions of CO₂ from E-fuel combustion in national emission totals, comparable to the present treatment of CO₂ from biomass combustion, which is reported separately from national totals. Furthermore, international agreement should be sought on methodologies and inventory categories to be used for reporting permanent CO₂ removals (e.g. DACCS).

The definitions frameworks of the RED II and the EU-ETS are consistent and ensure that CO₂ recovery for production of E-fuels cannot be subtracted from CO₂ emissions in ETS installations, thus close to the 2^nd option discussed for E-fuels GHG inventories.