Improvements to the Slope-Based Carbon Price Rescale Algorithm (module 47)

modules/47_regipol/regiCarbonPrice/datainput.gms

@@ -19,10 +19,15 @@ pm_emiMktTarget_dev(ttot,ttot2,ext_regi,emiMktExt) = 0;
 ***--------------------------------------------------
 $IFTHEN.emiMkt not "%cm_emiMktTarget%" == "off" 
 
+*** slope calculation algorithm parameters
+s47_slopeDegenerateThreshold = 1e-2; !! minimum emission change (fraction of 2005 emissions) for a reliable slope numerator
+s47_slopeMaxWindow = 5;              !! maximum iterations between reference and current; beyond this the reference is reset to stay local on the abatement cost curve
+
 *** Auxiliar parameters based on emission targets information
   loop((ttot,ttot2,ext_regi,emiMktExt,target_type_47,emi_type_47)$pm_emiMktTarget(ttot,ttot2,ext_regi,emiMktExt,target_type_47,emi_type_47), !!calculated sets that depends on data parameter
     regiEmiMktTarget(ext_regi) = yes; !! assigning values to set containing extended regions that have regional emission targets  
-    regiANDperiodEmiMktTarget_47(ttot2,ext_regi) = yes; !! assigning values to set containing extended regions and terminal years of regional emission targets  
+    regiANDperiodEmiMktTarget_47(ttot2,ext_regi) = yes; !! assigning values to set containing extended regions and terminal years of regional emission targets
+    p47_slopeUpperClampBound(ttot,ttot2,ext_regi,emiMktExt) = -0.3; !! initialize upper clamp bound for rescale slope 
   );
 
 *** Calculating set containing regions that should be controlled by a given regional emission target. 
@@ -106,6 +111,8 @@ p47_taxemiMkt_init(ttot,regi,emiMkt)$(p47_taxCO2eq_ref(ttot,regi) and (NOT(p47_t
 p47_factorRescaleSlope_iter("1","2020","2030",ext_regi,emiMktExt) = 0;
 *** initialize required parameter for cm_emiMktTarget rescale oscillation dampening.
 p47_factorRescaleemiMktCO2Tax_iter("1","2020","2030",ext_regi,emiMktExt) = 0;
+*** initialize required parameter to track if the upper slope clamp fired.
+p47_upperClampActive_iter("1","2020","2030",ext_regi,emiMktExt) = 0;
 
 $ENDIF.emiMkt
 

modules/47_regipol/regiCarbonPrice/declarations.gms

@@ -13,6 +13,8 @@
 Parameter
   s47_firstFreeYear                                  "value of first free year for the carbon price trajectory"
   s47_prefreeYear                                    "value of the last non-free year for the carbon price trajectory"
+  s47_slopeDegenerateThreshold                       "minimum emission change percentage relative to 2005 emissions required for a reliable slope; below this the slope numerator is treated as degenerate [fraction]"
+  s47_slopeMaxWindow                                 "maximum number of iterations between the reference iteration and the current iteration for slope calculation; beyond this the reference is reset to force a local slope [#]"
   pm_emiLULUCF_GrassiShift(ttot,all_regi)            "difference between Magpie land-use change emissions and UNFCCC emissions in 2015 to correct for national accounting in emissions targets [GtC]"
   pm_emiMktTarget_dev(ttot,ttot2,ext_regi,emiMktExt) "deviation of emissions of current iteration from target emissions, for budget target this is the difference normalized by target emissions, while for year targets this is the difference normalized by 2005 emissions [%]"
   pm_taxemiMkt(ttot,all_regi,all_emiMkt)                             "CO2 tax path per region and emissions market [T$/GtC]"
@@ -62,6 +64,9 @@ $endif.emiMktTargetType
   p47_factorRescaleemiMktCO2Tax_iter(iteration,ttot,ttot2,ext_regi,emiMktExt) "parameter to save rescale factor across iterations for debugging purposes [%]"
   p47_clampedRescaleSlope_iter(iteration,ttot,ttot2,ext_regi,emiMktExt) "auxiliary parameter to save the slope value before clamping. Useful for debugging purposes [#]"
   p47_dampedFactorRescaleemiMktCO2Tax_iter(iteration,ttot,ttot2,ext_regi,emiMktExt) "auxiliary parameter to save the rescale factor value before dampening. Useful for debugging purposes [#]"
+  p47_slopeUpperClampBound(ttot,ttot2,ext_regi,emiMktExt) "adaptive upper clamp bound for rescale slope; starts at -0.3 and halves after two consecutive triggers at the same level [#]"
+  p47_slopeUpperClampBound_iter(iteration,ttot,ttot2,ext_regi,emiMktExt) "adaptive upper clamp bound per iteration for debugging [#]"
+  p47_upperClampActive_iter(iteration,ttot,ttot2,ext_regi,emiMktExt) "1 if the upper slope clamp fired in this iteration, 0 otherwise [0 or 1]"
 
 *** Parameters necessary to define the CO2 tax curve shape   
   p47_targetConverged(ttot,ext_regi)                 "boolean to store if emission target has converged [0 or 1]"