Managing Aging Substation Structures

For electric utilities, limited outage availabilities and harsh environments are common. Preserving, maintaining, and retrofitting aging structures supporting critical assets is key to their longevity. In this paper, a twofold approach that is being developed and implemented by San Diego Gas & Electric (SDG&E) for managing their aging structures will be discussed: 1. Analysis of existing structures: A case study of how severe outage limitations impacted phasing the rebuilding of Point Loma substation and motivated preservation and retrofit of a 50-year old steel structure to accommodate all new electrical equipment. A case study of SPS1 substation steel rack structural analysis and repairs will also be presented. 2. Ongoing inspections and maintenance: It is important to have a program to perform routine inspections and maintenance of critical structural assets. This is especially important when faced with highly corrosive environments. A discussion of how this multi-year inspection and maintenance program is being implemented at SDG&E’s SONGS substation will be presented. This proactive approach to inspections and maintenance manages the high risks associated with deterioration. Aging infrastructure is a reality in the industry. Planning for it and accounting for it in project planning is key to a robust and sustainable utility infrastructure management program.