example 10.2   
for the same incremental costs unit1 should supply 125MW and unit 2 shold supply 100MW,for equal sharing each unit should supply 112.5MW
yearly extra cost is (671.88-699.22)8760 =12010781per year
this if the load is equally shared by the two units an extra cost of Rs.12010781 will be incurred.in other words economic loading would result in saving of Rs.12010781per year