Retirement Problems in Generation Expansion Planning

Percentage revenue requirements are shown to change little as generating plant service life estimates are varied from 35 to 65 years. However, early retirement of old plants may affect the schedule of new additions in a long-range expansion pattern. In general, lowest present worth of all future revenue requirements is obtained by keeping old plants in service. Individual exceptions may exist because of transmission costs or site value for particular units. Optimum retirement date is shown to be an inisensitive function of fixed operation and maintenance expenses for a particular unit.