dummy imports of CGHG emissions

[dtsintsk]

Hello, could you please help me with my current issue of dummy imports of negative emissions? The situation is the following, I am running a WAM scenario, including a scenario which limits CGHG emissions by 2050 to 4Mt. Model lets CGHG total emissions of 9147kt, then we have negative emissions by LULUCF of 2447, negative meissions by BECCS technology of 947.7 and remaining -1752kt is dummy imported as IMPMATS. I tried to shut down a user option of IMPMATS, which crashes the model. I wonder, why would not model choose some processes with less emissions or emoploy other capture technologies and instead decide to dummy import negative emissions, after all, it is so much more costly behavior. What could I be doing wrong? I can provide any material that is needed to solve this mistery

[Antti-L]

For me it does indeed look strange, because I think all the output flows of the IMPMATZ process should be non-negative flows. Maybe Amit could confirm that, and if he does, I think you probably have some modeling error affecting the IMPMATZ process itself. Unless Amit can also point out what might cause such, I could take a look at it, if you can provide the TIMES input files for this case (*.DD & *.RUN), plus the listing file *.LST.

[AKanudia]

Veda creates these IMP*Z processes as regular exogenous import processes. No recent changes here.. except from the new one - IMPDUCZ.

[Antti-L]

@Amit: So, I guess you would not expect negative output flows from IMPMATZ to occur at all?

[Antti-L]

Ok then, my guess is that you have somehow managed to define an auxiliary CGHG output flow for the IMPMATZ process, by some model data specification mistake, such that the auxiliary flow equals the activity of that process but with opposite sign, as shown in your results. By removing that modeling error you should be able to eliminate the dummy CGHG flow, and thereby any other GHG mitigation options available would most likely become used.

[dtsintsk]

I hope I understand it correctly, I am giving an example of how I have defined the LULUCF emissions for example. Here SINKLUL is MAT commodity and CGHG emission is attached to it as a negative number (see screenshots), however, it starts only 2025, I have very small negative CGHG IMPMATZ already in 2019 and 2021.

[Antti-L]

Please add -IMPMATZ into the PSet_PN column of that table where you define the ENV_ACT = -1, on the row for CGHG from SNKLUL.

[dtsintsk]

Please add -IMPMATZ into the PSet_PN column of that table where you define the ENV_ACT = -1, on the row for CGHG from SNKLUL.

Hi Antti, thank you, this helped solve the issue with negative CGHG