Electric System Reliability Annual Reports

Electric System Reliability Annual Reports were prepared in response to Commission Decision 96-09-045. This Decision imposed additional reliability recording, calculation, and reporting requirements on PG&E, Edison, SDG&E, Sierra Pacific Power, and PacifiCorp. Energy Division posts these reports as received, on the Commission's website for the convenience of customers and the public. Reports revised by a utility following staff review or for any other reason by the utilities will be posted as soon as possible after receipt.

System statistics are computed as follows: (1) including transmission, substation, and distribution outages, and (2) excluding planned outages. SAIDI (System Average Interruption Duration Index) and SAIFI (System Average Interruption Frequency Index) values include sustained outages, which are defined as outages lasting 5 minutes or more. MAIFI (Momentary Average Interruption Frequency Index) values include momentary outages, which are defined as outages lasting less than 5 minutes. The units for the reliability measures are:

  • SAIDI- minutes of sustained outages per customer per year
  • SAIFI- number of sustained outages per customer per year
  • MAIFI- number of momentary outages per customer per year

Annual Reports are available for the years listed below:

2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006  

2005 - 2004 | 2003 - 2002 | 2001 - 2000

1999 - 1998 - 1997


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