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Electric Power Annual 2010 Data Tables

With Data for 2010   |  Release Date:  November 09, 2011   |  Next Release Date: November 2012

Table 4.6. U.S. Transmission Circuit and Transformer Outages by Type and NERC Region, 2010
  FRCC MRO NPCC RFC SERC SPP TRE WECC Contigious
U.S.		 Contigious
U.S.
  Circuit Outages  
  AC DC
Circuit Outage Counts
Automatic Outages
Momentary 96 110 35 231 281 115 121 444 1,433 44
Sustained 136 217 70 264 320 128 71 838 2,044 61
Non-Automatic Outages
Operational 110 42 61 136 219 10 24 661 1,263 18
Planned 2,447 358 505 1,571 1,943 227 548 3,043 10,642 30
Circuit Outage Counts per 1,000 Circuit Miles
Automatic Outages
Momentary 13 6 5 9 8 15 13 7 8 11
Sustained 19 11 10 10 10 17 7 14 12 15
Non-Automatic Outages
Operational 15 2 9 5 7 1 3 11 7 4
Planned 344 19 75 62 58 29 58 51 63 7
Circuit Outage Hours
Automatic Outages
Sustained Initiate 6,864 7,619 14,530 13,341 4,642 1,117 1,089 22,422 71,623 3,261
Non-Automatic Outages
Operational 270 8 84 39 46 1 4 39 493 158
Planned 350 314 1,467 797 602 96 111 367 4,103 2,934
Circuit Outage Hours per Outage Incident[1]
Automatic Outages
Sustained Initiate 50 35 208 51 15 9 15 27 35 53
Non-Automatic Outages
Operational 2 0 1 0.29 0.21 0.09 0.17 0.06 0 9
Planned 0.14 1 3 1 0.31 0.42 0.20 0.12 0 98
                     
    Eastern Interconnection
(FRCC, MRO, NPCC, RFC,SERC, SPP)		 TRE WECC Contigious
U.S.		  
  Transformer Outages              
Transformer Outage Counts
Automatic Outages
Momentary       9 - 20 29  
Sustained       53 - 55 108  
Non-Automatic Outages
Operational       35 - 188 223  
Planned       316 - 214 530  
Transformer Outage Hours
Automatic Outages
Sustained       32,124 - 11,971 44,094  
Non-Automatic Outages
Operational       275 - 30 305  
Planned       1,543 - 257 1,800  
Notes:
[1] Circuit outage duration in hours per outage incident
· An Automatic Outage is an outage which results from the automatic operation of a switching device, causing an Element to change from an In-Service State to a not In-Service State.
· Momentary Outage is an automatic outage with an outage duration less than one minute.
· A Sustained Outage is an automatic outage with an outage duration of a minute or greater.
· A Non-Automatic Outage is an outage which results from the manual operation (including supervisory control) of a switching device, causing an element to change from an In-Service State to a not In-Service State.
· An Operational Outage is a Non-Automatic Outage for the purpose of avoiding an emergency (i.e., risk to human life, damage to equipment, damage to property) or to maintain the system within operational limits and that cannot be deferred.
· A Planned Outage is a Non-Automatic Outage with advance notice for the purpose of maintenance, construction, inspection, testing, or planned activities by third parties that may be deferred.
· Detailed information on the Transmission Availability Data System outage definitions is available at: http://www.nerc.com/docs/pc/tadswg/Appendix%207%2020101202a%20clean.pdf
Source: U.S. Energy Information Administration, Form EIA-411, "Coordinated Bulk Power Supply Program Report."