Posted on March 20, 2013

Projects, Technology Resulted in Record Electric Reliability for PG&E Customers in 2012

PG&E customers experienced the fewest minutes without electricity in company history in 2012. The just-released numbers for last year show that PG&E continues to make significant progress in electric reliability that benefit customers throughout its service area.

In 2012, not only did the average duration of a service interruption for a PG&E customer fall to an all-time low but also the number of service interruptions was the second lowest on record, just behind 2011.

“PG&E’s customers are experiencing the most reliable service in our company’s history thanks to significant investments to upgrade and modernize our electric facilities,” said Geisha Williams, executive vice president of Electric Operations for PG&E. “Building on that success, we are committed to further strengthening our operations to provide our customers with the safest and most reliable electric service possible.”

PG&E and other electric utilities measure the overall reliability of their systems using two primary indices defined by the Institute of Electrical and Electronic Engineers (IEEE). The System Average Interruption Duration Index (SAIDI) measures the number of minutes over the year that the average customer is without power. The System Average Interruption Frequency Index (SAIFI) measures the system-wide frequency of power interruptions per customer.

The numbers show that the average PG&E customer was without power for 131.5 minutes in 2012, down from 157 minutes in 2010 and 181 minutes in 2008. And, the frequency of power interruptions per customer in 2012 was 1.128 compared to 1.3 in 2008.

These improvements in dependable, reliable service are due to the utility’s ongoing investments in several key projects:

  • Targeted Circuit Program. In 2012, PG&E crews targeted 74 distribution circuits and eight transmission circuits based on their history of outages. Crews strengthened the circuits and used infrared technology to identify potential trouble spots so that stressed equipment could be repaired or replaced before it failed. By the end of 2013, PG&E will have upgraded more than 330 circuits in five years.
Bakersfield targeted circuits

In 2012, PG&E linemen Nick Walker and Paul Begley worked in a Bakersfield neighborhood to upgrade the electrical system by adding intelligent switches. (Currents Archive Photo.)

  • Intelligent Switches. Utility workers installed automated “intelligent” switches on 122 circuits in 2012. This Smart Grid technology dramatically reduces the amount of time it takes to restore power to customers. Instead of waiting for a crew to arrive on scene to restore circuits manually, the new devices do it automatically, often within five minutes. By the end of 2013, PG&E will have automated 400 circuits with this technology.  (Click here to read a Currents story on a project in Bakersfield where intelligent switches were installed.)
  • Rural Circuit Upgrades. PG&E installed more than 5,000 fuses and 500 reclosers on more than 600 of the worst-performing rural circuits since 2010 to isolate service interruptions and minimize their impact on customers.  
  • Substation Upgrades. Technicians have replaced and upgraded 138 substation transformers since 2010 to handle an increase in demand, to improve equipment performance or to maintain or restore service when electricity needs to be rerouted. (Click here to watch a Currents video of PG&E upgrading its Embarcadero substation in San Francisco.)
  • Vegetation Management Reliability Program. Crews worked to keep our electric lines free from trees and brush. Last year, crews either pruned or removed more than 26,500 trees that could have potentially caused a power outage. Since 2007, this program has reduced vegetation-related outages by 44 percent.

While PG&E has experienced across-the-board reliability improvements over the last couple of years, the company is focused on continuous improvement so that it can continue to meet its commitment to provide customers safe, reliable and affordable service.




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