How to constraint commodity flows among processes - Printable Version +- IEA-ETSAP Forum (https://iea-etsap.org/forum) +-- Forum: TIAM ETSAP (https://iea-etsap.org/forum/forumdisplay.php?fid=4) +--- Forum: Access and Use (https://iea-etsap.org/forum/forumdisplay.php?fid=11) +--- Thread: How to constraint commodity flows among processes (/showthread.php?tid=119) How to constraint commodity flows among processes - giulia realmonte - 23-04-2018 Dear all, since I am still new with TIMES and VEDA program, do you know how I can constraint a commodity flow among processes. In particular, I would like that the electricity (ELCC) used for an industrial process comes only from renewable sources. How can I do it with user constraints or generally scenario files? Regards, Giulia RE: How to constraint commodity flows among processes - Antti-L - 23-04-2018 Welcome to the IEA-ETSAP Forum! (23-04-2018, 08:57 PM)giulia realmonte Wrote: I would like that the electricity (ELCC) used for an industrial process comes only from renewable sources. How can I do it with user constraints or generally scenario files?In order to say how to implement such a constraint in TIMES, I think one would first need to see the algebraic formulation of such a constraint. Can you write it down mathematically, referring to process flow or activity variables (VAR_FLO, VAR_ACT), or possibly also other model variables? I am suggesting this just because at least for me it is not at all clear what exactly you mean mathematically when you say that the electricity (ELCC) used for an industrial process should come only from renewable sources. RE: How to constraint commodity flows among processes - giulia realmonte - 24-04-2018 (23-04-2018, 10:33 PM)Antti-L Wrote: Welcome to the IEA-ETSAP Forum! (23-04-2018, 08:57 PM)giulia realmonte Wrote: I would like that the electricity (ELCC) used for an industrial process comes only from renewable sources. How can I do it with user constraints or generally scenario files?In order to say how to implement such a constraint in TIMES, I think one would first need to see the algebraic formulation of such a constraint. Can you write it down mathematically, referring to process flow or activity variables (VAR_FLO, VAR_ACT), or possibly also other model variables? I am suggesting this just because at least for me it is not at all clear what exactly you mean mathematically when you say that the electricity (ELCC) used for an industrial process should come only from renewable sources. I am not able to provide a mathematical formulation, because I am not sure it is possible in TIAM to track commodity flows between different processes. I can provide you a scheme of what I intend, though [attachment=38] I don't want the first flow of commodity to take place, that is the ELCC coming out from coal plants should not be an input to AZDAC001 process. Differently I would like that the ELCC commodity input of AZDAC001 process comes from solar and wind processes. I am not sure this is possible and I fear that the only solution is to define a new ELCC_RNW commodity for electricity produced by solar and wind... RE: How to constraint commodity flows among processes - Antti-L - 24-04-2018 You can of course define a constraint requiring that the ELCC output from solar and wind power plants is greater than or equal to the input of electricity into some process(es), e.g. AZDAC00*, if that's what you mean, i.e. something like this: SUM({P | TOP(P,WIND,IN) or TOP(P,SOLAR,IN)} VAR_FLO(P,ELCC)) ≥ SUM({P ∈ AZDAC00*} VAR_FLO(P,ELCC)) And yes, you could also define a new commodity ELCC_RNW for electricity produced by solar and wind, and require that {P ∈ AZDAC00*} must consume that ELCC_RNW in amounts equal to consuming ELCC. But as such, I think it would accomplish the same thing, i.e. it would just constrain the amount of wind and solar electricity to be greater than or equal to the input to AZDAC00*, but maybe I am missing something? RE: How to constraint commodity flows among processes - giulia realmonte - 24-04-2018 (24-04-2018, 08:33 PM)Antti-L Wrote: You can of course define a constraint requiring that the ELCC output from solar and wind power plants is greater than or equal to the input of electricity into some process(es), e.g. AZDAC00*, if that's what you mean, i.e. something like this: SUM({P | TOP(P,WIND,IN) or TOP(P,SOLAR,IN)} VAR_FLO(P,ELCC)) ≥ SUM({P ∈ AZDAC00*} VAR_FLO(P,ELCC)) And yes, you could also define a new commodity ELCC_RNW for electricity produced by solar and wind, and require that {P ∈ AZDAC00*} must consume that ELCC_RNW in amounts equal to consuming ELCC. But as such, I think it would accomplish the same thing, i.e. it would just constrain the amount of wind and solar electricity to be greater than or equal to the input to AZDAC00*, but maybe I am missing something? Yes, I think that the first constraint could work for my case. How can I implement it through a UC spreadsheet? I am more familiar with constraint on capacity than on commodity flows... thanks again, Giulia RE: How to constraint commodity flows among processes - Antti-L - 24-04-2018 Below you can see a constraint block requiring that the ELCC output from wind and solar power plants is greater than or equal to the total ELCC input to AZDAC* processes in each period (from 2030) and timeslice. There is a small problem with the transmission losses, which are not automatically taken into account, and so I have used 0.95 as a crude approximate loss coefficient. [attachment=39]