Denise van Regemorter has made a good summary of the points that the user may need to consider with respect to peaking equations. The summary is given below, with some editorial changes:
Peaking Equation
A peaking equation can be activated for a commodity by defining the
peaking timeslices in the set COM_PKTS, or by defining the commodity to
be a member of the set COM_PEAK. In VEDA-FE, the COM_PKTS timeslices can
be defined in the ~FI_Comm table. (Using COM_PEAK is actually never needed, you can always use COM_PKTS instead.)
A single peaking equation combining several different ELC commodities (e.g. ELCHIG, ELCMED, ELCLOW) is sometimes needed. This can be accomplished by defining a user-defined commodity group containing the electricity commodities, and by defining COM_PKTS for the group. The peak equations will then be generated for the aggregated group, and not for the member commodities, unless the user has explicitly requested TIMES to generate them by defining COM_PKTS or COM_PEAK also for those member commodities. So, to eliminate these equations, just remove any such unnecessary specifications.
Additional notes:
1. Currently, the peak equations can be generated only for the timeslices at the commodity timeslice level. COM_PKTS(“annual”) means that a peak equation will be generated for all of those commodity timeslices. (In VEDA-FE, COM_PKTS can be defined for several individual timeslices by putting PEAKTS=ts1,ts2,…,tsn).
2. By using the SET PRC_PKNO one can exclude technologies from contributing to the peak. For example, possible electricity transmission technologies should normally not be included in the peaking equation, and should therefore be declared as belonging to the SET PRC_PKNO.
3. When defining the reserve margins with COM_PKRSV, one should take into account the grid-losses upstream of the peak consumption processes, either in the peak reserve (COM_PKRSV) or in the value of the (optional) COM_PKFLX parameter (default=0). However, on the production side of the peaking equation, any COM_IE efficiencies of the produced electricity commodities are already taken into account in the peak equation. Therefore, if any of the grid-losses have been modeled with such COM_IE parameters for the produced electricity, they should not be included in the peak reserve margin. Only those grid-losses that have been defined in some other way should be included in the reserve margin (e.g. the efficiencies of the grid transmission processes).
4. For each technology producing a peaking commodity one can also define an NCAP_PKCNT parameter for specifying the % contributing to the peak. If the associated timeslice is annual, the NCAP_PKCNT is value is defined for all peaking timeslices. The default value of NCAP_PKCNT is 1 for all of the peaking timeslices, and that should be reasonable in many cases. But the default value can be quite non-appropriate for technologies like solar or wind which cannot contribute so much to the peak. NCAP_PKCNT is always applied only on the production side. So, for example, if NCAP_PKCNT is defined for a trade process, it will be applied to the Imports only. For the consumption side (or Exports), FLO_PKCOI(R,T,P,C,TS) can be used to apply any given multiplier for the consumption that will occur during the peak.
5. If NCAP_PKCNT is explicitly defined for a process, it will override PRC_PKNO, but in that case the process will contribute to the peak only by its production in the peak timeslice, not by capacity. It has been implemented in this way, because in some cases one should not assume that the capacity contributes to the peak, but only the actual production during the peak, and by using NCAP_PKCNT you can accomplish that. In other words, if you specify PRC_PKNO and no NCAP_PKCNT, the process will have no contribution to the peak; but if NCAP_PKCNT is also specified, the process will contribute to the peak by its production multiplied by the NCAP_PKCNT value, instead of the capacity.
Note also that existing powerplants do also appear in the peak equation, but because their capacities are usually defined by either RESIDs or PASTIs, their contribution is included only in the RHS constant of the equation.