Force committed generators (status=2) to be built at start year - fixes bug where they were optional like candidates

Author: lucas-vivier

epm/main.gms

@@ -716,6 +716,12 @@ vBuild.fx(eg,y)$(pGenData(eg,"StYr") <= sStartYear.val) = 0;
 * Set the upper limit for new generation builds per year, accounting for the annual build limit and year weighting
 vBuild.up(ng,y) = pGenData(ng,"BuildLimitperYear")*pWeightYear(y);
 
+* Force committed generators (status=2) to be built at their start year.
+* Unlike candidates, committed generators are not optional - they must be built.
+* They remain in ng(g) so their CAPEX is included in total cost (unlike existing generators).
+* Note: BuildLimitperYear is ignored for committed generators - full capacity is built at StYr.
+vBuild.lo(ng,y)$(gstatusmap(ng,'committed') and (pGenData(ng,"StYr") = y.val)) = pGenData(ng,"Capacity");
+
 * Define the upper limit for additional transmission capacity, subject to high transfer allowance
 vNewTransmissionLine.up(sTopology(z,z2),y)$fAllowTransferExpansion = symmax(pNewTransmission,z,z2,"MaximumNumOfLines");