Probabilistic economic evaluation of substation seismic upgrade

The authors present a methodology for deciding whether or not to implement seismic design modifications at Southern California Edison´s (SCEs) substation facilities. The method considers the potential for substation capability loss resulting from earthquake damage, cost of seismic modification made today, the cost of damage restoration after that modification is made, the cost of doing nothing now, and the site-specific earthquake probability. On the basis of these findings, recommendations for seismic modifications of substation facilities could be made. A `crossover year´ is developed which shows a net savings period and net cost period depending upon whether the seismic event takes place prior to or after the crossover year