Commodity group auxiliary input

[pedodds]

I've been trying to use a commodity group (CO2_SEQUEST) as an auxiliary input to a process.  While VEDA-BE does not produce an error, and registers the commodity group with VDA_FLOP (screenshot #2), it does not treat it as an auxiliary input (screenshot #1) and ignores it in model runs.

Is it possible to use a commodity group as an auxiliary input?

Thanks and best wishes,

Paul

   

   

[Antti-L]

Do you mean that CO2_SEQUEST is a user-defined group of commodities?

If so, you cannot define that group as an input or an output, but you have to define the intended member commodities as such. TIMES does not allow genuine commodity groups in the topology.
Then you can define the VDA_FLOP parameter for the group, just as shown in your screenshot. The group can be specified in the Other_Indexes column. Alternatively, you could use ACT_EFF on the group (with the inverse value).

And, if the member commodities are of type ENV (while HYGL is NRG), there is no need to define the members as auxiliary inputs, but just normal inputs in the topology.

[pedodds]

Thanks, Antti, that's very helpful to know. CO2_SEQUEST was a user-defined group of commodities, so I've adopted a different approach.

[Antti-L]

Oh, why a different approach?

Did you not like my suggestion to define the members in the process topology?

[pedodds]

The members of the commodity group, which were emissions, were anyway aggregated to a single commodity in the model, so I just used that - not so tidy but the same functionality.

It wasn't at all a reflection on your approach - I adopted that approach before posting the question, when my initial approach didn't work, but I asked because I (and probably others) wanted to understand why it didn't work.

[Antti-L]

Ok, nice to know!

I think it is quite tidy in that aggregated way, at least if you use a process to aggregate them into a single commodity.
But if using COM_AGG to aggregate them, one should remember that the consumption of the aggregated commodity will not be reflected in the source commodity balances, unlike in the aggregation-via-process case.