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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 4.7.B. U.S. Transmission Circuit Sustained Automatic Outage Hours by Cause Code and by NERC Region, 2010
  FRCC MRO NPCC RFC SERC SPP TRE WECC Contigious
U.S.		 FRCC MRO NPCC RFC SERC SPP TRE WECC Contigious
U.S.
        AC & DC Circuit Outage Hours             Percent        
Sustained Outage Causes                                    
Weather, excluding lightning - 2,050 21 568 849 668 0.05 4,626 8,782 - 22.3 0.1 4.1 18.3 59.8 0.0 19.5 11.7
Lightning 8 2 1 82 130 38 26 101 388 0.1 0.0 0.0 0.6 2.8 3.4 2.4 0.4 0.5
Environmental - 2 - 8 202 - - 11 222 - 0.0 - 0.1 4.3 - - 0.0 0.3
Contamination 9 17 0.02 - 446 2 0.02 37 512 0.1 0.2 0.0 - 9.6 0.2 0.0 0.2 0.7
Foreign Interference 74 0.03 835 92 150 - 23 57 1,232 1.1 0.0 5.7 0.7 3.2 - 2.1 0.2 1.6
Fire 0.08 - 766 12 4 27 - 373 1,181 0.0 - 5.3 0.1 0.1 2.4 - 1.6 1.6
Vandalism, Terrorism, or Malicious Acts - - - - - - - 18 18 - - - - - - - 0.1 0.0
Failed AC Substation Equipment 6,091 614 11,329 8,863 715 27 625 3,496 31,761 88.7 6.7 78.0 64.4 15.4 2.4 57.4 14.8 42.4
Failed AC/DC Terminal Equipment - 812 - 429 - - - 9 1,250 - 8.8 - 3.1 - - - 0.0 1.7
Failed Protection System Equipment 36 38 223 396 223 5 50 116 1,086 0.5 0.4 1.5 2.9 4.8 0.5 4.6 0.5 1.5
Failed AC Circuit Equipment 521 4,742 1,235 2,489 1,380 90 342 3,353 14,152 7.6 51.5 8.5 18.1 29.7 8.1 31.4 14.2 18.9
Failed DC Circuit Equipment - 56 - - - - - 47 102 - 0.6 - - - - - 0.2 0.1
Vegetation - - 27 4 115 4 - 78 228 - - 0.2 0.0 2.5 0.4 - 0.3 0.3
Power System Condition 1 228 54 12 - 138 4 131 569 0.0 2.5 0.4 0.1 - 12.3 0.4 0.6 0.8
Human Error 9 457 12 48 244 0.20 6 318 1,095 0.1 5.0 0.1 0.3 5.3 0.0 0.6 1.3 1.5
Unknown 83 12 1 513 66 79 13 1,998 2,765 1.2 0.1 0.0 3.7 1.4 7.1 1.2 8.4 3.7
Other 32 174 26 253 118 39 0.15 8,899 9,542 0.5 1.9 0.2 1.8 2.5 3.5 0.0 37.6 12.7
TOTAL 6,864 9,204 14,530 13,770 4,642 1,117 1,089 23,669 74,884 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
Notes:
• Detailed information on the Transmission Availability Data System outage causes 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."