Hello Dr. Antti,
I want to model a carbon emission budget constraint in my model using AnswerTIMES. For example, I have to model a total CO2 emission budget of 100 MT (from 2012 to 2050) on my power system model of Country A which runs from 2012 to 2052 (input years). I have already modelled CO2 emission as an output in each fossil fuel-based process depending on its fuel consumption and emission factor. Further, I have also created a process filter (CO2_EMISS) to select all the process who has one of the output commodity as CO2.
Now to create the constraint, I am selecting the UC by Region (Sum over periods and timeslices). However, I am not able to decide which parameter to be selected to implement this CO2 budget over the model horizon for a selected time period as I need to input one single budget value on CO2 emission.
may you please share your views on this?
Regards
Vinay Saini
> I am not able to decide which parameter to be selected to implement this CO2 budget over the model horizon for a selected time period as I need to input one single budget value on CO2 emission.
Have you tried UC_CUMCOM? I think using it would be fine, if the emissions to be constrained are represented by a commodity or several commodities. Adding some UC_CUMFLO terms may be necessary if the emissions from certain processes should be excluded from the budget constraint.
See the example on the VEDA Forum:
Carbon Budgets Excluding Processes using UC_FLO
Dear Dr Antti,
I am not sure how to use UC_Cumcom.
Further, on the link, it mentions something about Comnet which as per the Times documentation is the Coefficient of the net commodity production variable VAR_COMNET in a user constraint.
So, I tried using UC_Comnet in AnswerTIMES (User Constraint). However, I am not sure where to put the 100 MT CO2 budget. Please see the image file and suggest whether this is the correct way of representation.
Although the model didn't optimize, I would like to know whether I have modeled it correctly or not.
I want to model the following:
Total/Net CO2 Emission in the model (from 2012 to 2050) < 100 MT of CO2 Emission
I have modeled CO2 as a separate commodity coming out from fossil fuel processes.
Regards
Vinay Saini
No, I did not mean UC_COMNET, but UC_CUMCOM.
UC_COMNET is a coefficient for the annual emissions, while UC_CUMCOM is for cumulative emissions. Under ANSWER, it comes in two flavors: UC_CUMCOMNET and UC_CUMCOMPRD. If your emissions to be constrained are represented by the NET variables, then just use UC_CUMCOMNET under ANSWER.
Did you not see the example in that thread, where a budget was defined for the emissions between 2020 and 2075? It is very simple and straightforward... Sorry but I don't quite see why you did not follow that example? Is there something unclear about it?
To answer your question "I would like to know whether I have modeled it correctly or not. ":
Sure, you can also use UC_COMNET, if you only want to constrain the emissions over the full model horizon. TIMES by default multiplies the coefficients by the duration of each period, if the constraint is cumulative. I am not able to spot any problems in your constraint, and so it should indeed work for that purpose. But you also said "the model didn't optimize", which I don't really understand...
Actually, I found an example already in the ANSWER Example4 demo database, although with UC_CUMCOMPRD. But it is exactly similar with UC_CUMCOMNET. See below both alternatives, of which you should choose NET or PRD depending on how you model your emissions:
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Dear Dr. Antti,
Your last reply really helped me a lot. Since I was making a cumulative constraint for the first time so I wasn't really sure where to put the data for LHS and RHS. As it was clear from my earlier reply that I did a mistake in prescribing the LHS side of the constraint which I prescribed in the TS data field instead of the TID.
Now I have modelled the constraint using the UC_CUMCOMPRD as shown in the attached image. I have tested the model, it is working fine and giving the output as expected.
Apologies I could not follow your link as the excel files were not accessible to me being a non-member of the VEDA forum. Now, I have registered on the same so will be able to see them in detail.
Thanks again for your support and timely reply.
Regards
Vinay Saini