Economic Incentives for Larger Transmission Conductors

The power industry initially designed 500 kV transmission lines in the early 1960´s. Then, as now, cost of losses versus installed cost evaluations were made to assess conductor requirements. At that time, independent of the economic analysis, electrical environmental criteria limited the minimum allowable conductor sizes. That is, radio interference mitigation required larger conductor sizes than did economic requirements. By today´s measures, energy was inexpensive, and smaller conductor sizes would have satisfied an optimum balance between initial cost and operation cost.