ZGlobal Retained to Evaluate the Caltrain Modernization (CalMod) Program

The project includes full conversion to an electric fleet, platform and station improvements, extension of service to Downtown San Francisco, and other projects that allow Caltrain to grow and evolve with the Bay Area.

ZGlobal services include the design of two substations, interconnection services to PG&E 115kv lines as well as cost allocation and reliability studies. ZGlobal recently concluded as part of the Caltrain electrification project, assessment of Caltrain’s request for two electric distribution services circuits, or feeders, from PG&E at the FMC substation in San Jose area. One of the feeders will serve as the primary source of electricity powering the Caltrain electrification project. The secondary feeder is a backup to the primary feeder designed to improve electrical service reliability.

PG&E concluded that the FMC substation would have to be totally rebuilt and reconfigured to provide two feeders to Caltrain at a cost of nearly $65 million. PG&E also suggested that if Caltrain would be satisfied with one feeder, that the FMC substation rebuild could be avoided and accommodating a single feeder would cost less than $5 million. The large incremental cost for the second feeder begs the question of whether the additional feeder will be worth the additional $60 million in capital costs and increased maintenance costs.

We concluded that under the one-feeder option, the total expected amount of time a Caltrain rider may experience a sustained outage (being without power for more than five minutes) annually is estimated to be 69 minutes/year or 99.9878% reliability. We also concluded that under the two-feeder option, the total expected amount of time that a Caltrain rider may experience a sustained outage annually is estimated to be 32 minutes/year or 99.9939% reliability.

This equals a net decrease in sustained outages of 37min/yr. The two-feeder option represents 0.0074% reliability increase over the one-feeder option. However, achieving 37 min/year decrease in annual outage time comes at a cost of $65 million plus incremental maintenance costs. More work is under way to model and calculate the probability of an outage during the peak period (rush hours) where Caltrain riders can experience degradation of services.