about Trade process

[myhan]

Dear support teams,

I defined the transmission process and set its Stock and Cost parameters for one region, which we'll call `Reg1`. However, when reporting results, `Reg2` still shows `capacity (VAR_CAP)`, and it doesn't match Reg1's capacity. Why is this happening? Can I force the capacities of these two regions to be equal?


Best regards,
myhan

[Antti-L]

I think that should not be happening, unless you have some parameters referring to that capacity in Reg2 (bounds, UC_CAP, capacity costs, etc.).  I could give an full explanation why it is happening, if you could provide a reproducible case.

Yes, you could force the capacities to be equal with a user-constraint.

[myhan]

How do I apply this constraint? I want to enforce equal new capacity across both regions and try again.

Thanks very much.

[Antti-L]

In TIMES it is quite easy.  For example, assuming that the IRE process is named 'IRE12', one could define a constraint 'UC_IRE12' with the following parameters:

  UC_NCAP('UC_IRE12','LHS','REG1',T,'IRE12')  =  1;
  UC_NCAP('UC_IRE12','LHS','REG2',T,'IRE12')  = -1;
  UC_RHST('UC_IRE12','0','FX') = 2;

Under VEDA you would probably also need to set R_S: Reg1, Reg2 (or Allregions).

However, I wonder why you now would wish to force such. In your first post, you said: "I defined the transmission process and set its Stock and Cost parameters for one region, which we'll call `Reg1`. However, when reporting results, `Reg2` still shows `capacity (VAR_CAP)`".  That sounds to me like you originally wished that there would be no capacity in Reg2.  So, I am confused why you now want to force a capacity to exist and be reported also for Reg2. 

[myhan]

Thank you very much for your patient and detailed explanation — it was very helpful.

My motivation is the following: in TIMES the inter-regional transmission (IRE) process is effectively represented in both regions, so the model reports a capacity (VAR_CAP) on both the Reg1 and Reg2 “sides”. Conceptually, though, this nameplate capacity is a single physical asset associated with the transmission link/process itself, not two regions-linked process capacity.

In my current setup I only assigned investment/stock/cost parameters in one region (Reg1). As a result, the reported capacities in Reg1 and Reg2 are not necessarily equal in the solution output, which creates confusion when interpreting the capacity of the line. To address this, I would like to add a constraint to enforce equality between the two reported capacities (e.g., VAR_NCAP in Reg1 equals VAR_NCAP in Reg2). Then, when presenting results, I plan to report the physical line capacity as the average of the two sides (i.e., divide the sum by 2), so it corresponds to the single transmission asset.

Thank you again for your guidance (especially the UC_NCAP example) — I’ll implement this in VEDA with the appropriate region set.

One quick follow-up: if there are many transmission links/IRE processes, is there a simpler or more scalable way to impose this equality (e.g., using a wildcard, process set, or some generic template in VEDA), rather than defining one UC constraint per line?

Best regards,