PUC Annual Report–Fiscal Year 2004-05 - Public Utilities Commission

Public Utilities Commission Annual Report 2004-05State of Hawaii Page 692.00Figure 43HECO System Average Interruption Frequency (SAIF)(Lower is better)1.801.601.7611.650Interruptions1.401.201.000.801.2651.1541.2700.600.400.200.002000 2001 2002* 2003 2004**Year*Data normalized to exclude 12/19/02 AES Load Shedding outage**Data normalized to exclude 1/14/04-1/15/04 High Winds, 2/26/04-2/28/04 Storm, and 3/3/04Pukele OutagesFigure 43 shows the SAIF indices for the past five (5) years. It shows that in 2004 theSAIF was the third lowest in the past five (5) years at 1.27, or slightly more than one (1) outageper customer for the year. Compared to past history, the 2004 SAIF of 1.27 was significantlybelow the ten (10) year 1.57 SAIF average.An increase in winter weather outages contributed to a higher SAIF for 2004. Thefour (4) major weather related categories - High Winds, Trees or Branches 23 , Lightning andUnknown Failures affected a total of 107,303 customers during 2004 compared to a total of72,242 customers during 2003, an increase of 48%. However, improvements were noted in theareas of Equipment Deterioration, Auto Accidents, and Switching Errors over 2003 SAIF results.Two (2) sustained interruptions affected 10,000 or more customers during 2004.Approximately 22,466 customers were affected by these top two (2) interruptions for 2004,contributing 0.08 to the SAIF. Of the two (2) sustained interruptions, one (1) occurred on the subtransmissionsystem while tied to the adjacent line for maintenance work, and the secondoccurred on the sub-transmission system during a Lightning Storm in the Mililani area onJanuary 22, 2004.23 A vegetation management program has also helped to reduce tree-related outages.