Peaking Equation

[Yacine]

Hello,
I was wondring why CHP process are not participating in the electricity peaking reserve equation by their Capacity.
Thanks you for your response.

[Antti-L]

It is so by default, because 1) crediting by capacity would be a bit dangerous, as the capacity of CHP processes may be modeled in different ways, and 2) "back-pressure" type of CHP plants typically cannot be "regulated" sufficiently for being credited with their electrical capacity (they can only produce when there is sufficient heat demand).  But for pass-out turbine plants modeled with electrical capacity one could well assume contribution by Capacity, and you can define that by setting PRC_PKAF for the process.  You can then use NCAP_PKCNT for overriding AF as the contribution factor.

[Yacine]

It is so by default, because 1) crediting by capacity would be a bit dangerous, as the capacity of CHP processes may be modeled in different ways, and 2) "back-pressure" type of CHP plants typically cannot be "regulated" sufficiently for being credited with their electrical capacity (they can only produce when there is sufficient heat demand).  But for pass-out turbine plants modeled with electrical capacity one could well assume contribution by Capacity, and you can define that by setting PRC_PKAF for the process.  You can then use NCAP_PKCNT for overriding AF as the contribution factor.

Dear Antti,
Thank you for your reply. In my case I am working only on the electricity sector with a heat demand equal to zero. I have some observations:

First, I converted all the CHP process to the ELC group and deleting the CHPR parameter, but the problem remains (CHP are participating with their VAR_FLO not VAR_NCAP). I think this is due to the fact that a process producing two commodities will automatically participates by its VAR_FLO. For example a Hydro process producing ELCHIG and ELCMED also particpate with the VAR_FLO (the same thing as a CHP process producing ELCHIG and HEAT).



I applied your method activating the PRC_PKAF and using the NCA_PKCNT=1, and it works.



The vintiaging method used in the equation, add some VAR_FLO to the equation for the CHP process.  For example for the 2045 peaking equation I have this additional lines:
+ 0.952380952380952 VAR_FLO(UK.2017.2045.CHPPUBBGAS201.ELCHIG.DJFBP7)#9996177
                                 + 0.952380952380952 VAR_FLO(UK.2017.2045.CHPPUBSBCOH101.ELCHIG.DJFBP7)#9996369
                                 + 0.952380952380952 VAR_FLO(UK.2020.2045.CHPPUBBGAS201.ELCHIG.DJFBP7)#10021630
                                 + 0.952380952380952 VAR_FLO(UK.2020.2045.CHPPUBSBCOH101.ELCHIG.DJFBP7)#10021822
                                 + 0.952380952380952 VAR_FLO(UK.2025.2045.CHPPUBBGAS201.ELCHIG.DJFBP7)#10044957
                                 + 0.952380952380952 VAR_FLO(UK.2025.2045.CHPPUBSBCOH101.ELCHIG.DJFBP7)#10045149
                                 + 0.952380952380952 VAR_FLO(UK.2030.2045.CHPPUBBGAS201.ELCHIG.DJFBP7)#10068092
                                 + 0.952380952380952 VAR_FLO(UK.2030.2045.CHPPUBIGWOO101.ELCHIG.DJFBP7)#10068476
                                 + 0.952380952380952 VAR_FLO(UK.2030.2045.CHPPUBSBCOH101.ELCHIG.DJFBP7)#10068668
                                 + 0.952380952380952 VAR_FLO(UK.2030.2045.CHPPUBSMUN01.ELCHIG.DJFBP7)#10068860
                                 + 0.952380952380952 VAR_FLO(UK.2030.2045.CHPPUBSPWOO101.ELCHIG.DJFBP7)#10069052
                                 + 0.952380952380952 VAR_FLO(UK.2035.2045.CHPPUBBGAS201.ELCHIG.DJFBP7)#10090139
                                 + 0.952380952380952 VAR_FLO(UK.2035.2045.CHPPUBIGWOO101.ELCHIG.DJFBP7)#10090907
                                 + 0.952380952380952 VAR_FLO(UK.2035.2045.CHPPUBSBCOH101.ELCHIG.DJFBP7)#10091099
                                 + 0.952380952380952 VAR_FLO(UK.2035.2045.CHPPUBSMUN01.ELCHIG.DJFBP7)#10091291
                                 + 0.952380952380952 VAR_FLO(UK.2035.2045.CHPPUBSPWOO101.ELCHIG.DJFBP7)#10091483
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.CHPPUBBGAS201.ELCHIG.DJFBP7)#10106853
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.CHPPUBIGWOO101.ELCHIG.DJFBP7)#10107941
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.CHPPUBSBCOH101.ELCHIG.DJFBP7)#10108133
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.CHPPUBSMUN01.ELCHIG.DJFBP7)#10108965
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.CHPPUBSPWOO101.ELCHIG.DJFBP7)#10109157
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.EUFCHH201.ELCHIG.DJFBP7)#10109477
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.EUMFCBGS110.ELCHIG.DJFBP7)#10110501
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.EUMFCGAS101.ELCHIG.DJFBP7)#10110821
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.EUSFCBGS210.ELCHIG.DJFBP7)#10111833
                                 + 0.952380952380952 VAR_FLO(UK.2040.2045.EUSFCGAS201.ELCHIG.DJFBP7)#10112153


Also, in the equation the base_year investments PASTI are not represented as variables. Are they represented in the right-hand side  (Sum(varibles)>-RHS = base_year participation).


The last observation, is about the transformers process HIGH_MED and MED_LOW. I set a capacity credit of 0, but in the equation they participate with VAR_ACT ?


Thank you

[Antti-L]

Thanks for the follow-up.

Yes, if the PCG of a process contains more than one commodity, such a process by default contributes to the peaking equation by the output only. I am glad you found the PRC_PKAF working.

I am not aware of the situation where some VAR_FLOs would be added to the equation for CHP processes, even if PRC_PKAF is used. Maybe you can give more info about the conditions under which this may occur?

Yes, any existing capacities are included in the constant term.

I think you should use PRC_PKNO for excluding processes from the peaking equation (and do not set NCAP_PKCNT).

[Antti-L]

I just tested with a vintaged CHP process, using PRC_PKAF.  I am not seeing any VAR_FLO terms in the peaking equation for it; only VAR_NCAP terms (contributing by capacity) as expected.  So, I cannot confirm you findings about some VAR_FLO being added to the equation for a CHP process.