The THETIS regulation allows ships to use different emmission monitoring methods, named A to D. If my understanding is correct, A is the least precise one, and D the most precise one.
- A: BDN and period stock takes of fuel tanks
- B: Bunker fuel tank monitoring on-board
- C: Flow meters for applicable combustion processes
- D: Direct CO2 emissions measurement
In the whole THETIS fleet there are only 2 ships that use the method D:
- Mount Kimbo - IMO 9470997, a chemical tanker
- MP MR Tanker 1 - IMO 9472763, another chemical tanker
Methods used by passenger ferries
This graph represents the distribution of passenger ferries within the GreenFerries scope grouped per monitoring method:
We can see that unfortunately the most used monitoring method is the least precise one, A. Also, a non-negligeable number of ships declare that they use multiple monitoring methods, which makes things quite complicated if we want to compare ships.
We have been warned that it is probably wrong to compare ships that use different monitoring methods because their result may differ only because of the method used. However, this is exactly what we are doing currently with the EcoScore. We are still looking for a harmonization method to be able to readjust figures depending on the monitoring method used.