Table 11.2 Reliability Metrics Using IEEE of U.S. Distribution System by State, 2023 and 2022 |
All Events (With Major Event Days) | Without Major Event Days | Loss of Supply Removed | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Percent of Customers Reported | SAIDI (minutes per year) |
SAIFI (times per year) |
CAIDI (minutes per interruption) |
SAIDI (minutes per year) |
SAIFI (times per year) |
CAIDI (minutes per interruption) |
SAIDI (minutes per year) |
SAIFI (times per year) |
CAIDI (minutes per interruption) |
|||||||||||
Census Division and State |
Year 2023 | Year 2022 | Year 2023 | Year 2022 | Year 2023 | Year 2022 | Year 2023 | Year 2022 | Year 2023 | Year 2022 | Year 2023 | Year 2022 | Year 2023 | Year 2022 | Year 2023 | Year 2022 | Year 2023 | Year 2022 | Year 2023 | Year 2022 |
New England | 83.3% | 85.5% | 489.3 | 309.3 | 1.368 | 1.341 | 357.7 | 230.7 | 103.4 | 98.2 | 0.919 | 0.972 | 112.5 | 101 | 481.2 | 349.9 | 1.298 | 1.333 | 370.7 | 262.4 |
Connecticut | 79.0% | 78.5% | 193.4 | 187.4 | 0.911 | 0.905 | 212.4 | 207 | 77.7 | 73.7 | 0.681 | 0.673 | 114 | 109.4 | 188.2 | 187.1 | 0.876 | 0.897 | 214.9 | 208.5 |
Maine | 100.8% | 102.7% | 1863 | 963.6 | 3.314 | 3.001 | 562.2 | 321.1 | 247.4 | 216.7 | 1.979 | 1.956 | 125 | 110.8 | 1781.4 | 930.7 | 3.015 | 2.786 | 590.9 | 334.1 |
Massachusetts | 86.0% | 90.9% | 265.3 | 165.8 | 1.069 | 1.093 | 248.2 | 151.7 | 83.5 | 84.4 | 0.79 | 0.897 | 105.7 | 94 | 268.5 | 186.4 | 1.025 | 0.997 | 262 | 186.9 |
New Hampshire | 88.2% | 88.2% | 590.6 | 495.5 | 1.485 | 1.417 | 397.7 | 349.6 | 89.3 | 78.2 | 0.766 | 0.7 | 116.6 | 111.8 | 587.7 | 487.4 | 1.48 | 1.383 | 397.2 | 352.5 |
Rhode Island | 98.3% | 98.2% | 104.6 | 81.9 | 0.782 | 0.959 | 133.7 | 85.4 | 52.2 | 63.2 | 0.667 | 0.808 | 78.3 | 78.2 | 100.8 | 81.1 | 0.736 | 0.932 | 136.9 | 87 |
Vermont | 10.4% | 10.5% | 486.3 | 914.6 | 2.25 | 2.44 | 216.1 | 374.8 | 204.3 | 178.5 | 1.38 | 1.95 | 148.1 | 91.5 | 480.1 | 877.6 | 2.04 | 2.26 | 235.3 | 388.3 |
Middle Atlantic | 58.8% | 58.7% | 196.8 | 184.7 | 1.041 | 1.102 | 189 | 167.7 | 112.2 | 111.7 | 0.89 | 0.952 | 126.1 | 117.3 | 185.9 | 176.3 | 0.951 | 1.017 | 195.5 | 173.3 |
New Jersey | 99.3% | 99.2% | 108.2 | 89.6 | 0.88 | 0.876 | 122.9 | 102.3 | 88 | 78.7 | 0.83 | 0.838 | 106 | 94 | 99.2 | 81.4 | 0.783 | 0.776 | 126.8 | 104.9 |
New York | 20.0% | 20.1% | 204.8 | 347.7 | 1.127 | 1.466 | 181.7 | 237.2 | 130.1 | 150 | 0.963 | 1.162 | 135.1 | 129.1 | 207.5 | 354 | 1.14 | 1.489 | 182 | 237.7 |
Pennsylvania | 84.3% | 84.1% | 265.1 | 207.5 | 1.143 | 1.163 | 232 | 178.3 | 125.9 | 125.4 | 0.914 | 0.975 | 137.7 | 128.6 | 248.3 | 195.1 | 1.025 | 1.059 | 242.3 | 184.2 |
East North Central | 91.0% | 90.8% | 489.5 | 319.7 | 1.187 | 1.212 | 412.3 | 263.8 | 108.8 | 121.4 | 0.808 | 0.931 | 134.6 | 130.4 | 483.4 | 288.6 | 1.113 | 1.09 | 434.5 | 264.8 |
Illinois | 96.3% | 95.8% | 210.4 | 90.8 | 0.833 | 0.756 | 252.4 | 120.2 | 56.2 | 59.1 | 0.604 | 0.643 | 93 | 91.9 | 209.9 | 89.2 | 0.819 | 0.745 | 256.4 | 119.8 |
Indiana | 83.4% | 83.3% | 467.4 | 276.5 | 1.414 | 1.427 | 330.6 | 193.7 | 111.3 | 139.9 | 0.944 | 1.136 | 118 | 123.2 | 462.1 | 217.6 | 1.292 | 1.229 | 357.6 | 177 |
Michigan | 94.2% | 94.1% | 1127.7 | 520.7 | 1.543 | 1.34 | 730.9 | 388.7 | 164.8 | 166.8 | 0.931 | 1.016 | 177.1 | 164.2 | 1131.2 | 519.9 | 1.533 | 1.326 | 738 | 391.9 |
Ohio | 96.4% | 96.2% | 366.6 | 413.6 | 1.252 | 1.518 | 292.7 | 272.4 | 127.1 | 144.1 | 0.918 | 1.122 | 138.4 | 128.5 | 336 | 318.9 | 1.075 | 1.204 | 312.6 | 264.8 |
Wisconsin | 74.5% | 74.3% | 203.8 | 307.9 | 0.913 | 1.101 | 223.3 | 279.6 | 76.8 | 104.7 | 0.633 | 0.763 | 121.4 | 137.3 | 200.9 | 305.2 | 0.881 | 1.053 | 228 | 289.8 |
West North Central | 76.2% | 75.9% | 222.7 | 202.8 | 1.093 | 1.107 | 203.8 | 183.2 | 84.6 | 90.1 | 0.811 | 0.868 | 104.3 | 103.9 | 215.6 | 191.7 | 0.973 | 0.98 | 221.5 | 195.7 |
Iowa | 52.8% | 52.8% | 83.9 | 95 | 0.859 | 0.978 | 97.7 | 97.2 | 60.7 | 78.2 | 0.645 | 0.837 | 94.1 | 93.5 | 75.5 | 80.1 | 0.741 | 0.76 | 101.9 | 105.4 |
Kansas | 80.1% | 79.7% | 287.1 | 178.3 | 1.327 | 1.321 | 216.3 | 134.9 | 101.8 | 108.1 | 1.004 | 1.087 | 101.4 | 99.5 | 274.4 | 157.9 | 1.171 | 1.143 | 234.3 | 138.2 |
Minnesota | 86.7% | 86.6% | 127.1 | 275.2 | 0.973 | 1.207 | 130.6 | 228 | 72.8 | 81 | 0.778 | 0.846 | 93.6 | 95.8 | 123.6 | 270.3 | 0.859 | 1.101 | 143.9 | 245.5 |
Missouri | 83.6% | 83.1% | 379 | 149.5 | 1.324 | 1.057 | 286.1 | 141.5 | 104.4 | 97 | 0.878 | 0.879 | 118.9 | 110.3 | 391.2 | 144.2 | 1.263 | 0.985 | 309.8 | 146.3 |
Nebraska | 67.0% | 66.1% | 69.4 | 73 | 0.555 | 0.59 | 125.2 | 123.8 | 55.6 | 56.2 | 0.478 | 0.534 | 116.2 | 105.2 | 66.4 | 71.1 | 0.545 | 0.573 | 121.8 | 124 |
North Dakota | 63.2% | 63.2% | 262.3 | 677.6 | 1.151 | 1.425 | 227.9 | 475.5 | 93.9 | 102.8 | 0.942 | 1.065 | 99.7 | 96.6 | 259 | 789.8 | 0.843 | 1.126 | 307.2 | 701.2 |
South Dakota | 67.9% | 67.8% | 78.1 | 338.3 | 1.017 | 1.204 | 76.8 | 281.1 | 63.9 | 126.3 | 0.894 | 0.793 | 71.4 | 159.4 | 62.2 | 244.7 | 0.691 | 0.89 | 90.1 | 274.9 |
South Atlantic | 81.7% | 80.2% | 240.4 | 615.8 | 1.341 | 1.662 | 179.4 | 370.5 | 119.7 | 127.9 | 1.071 | 1.097 | 111.9 | 116.6 | 211.7 | 635 | 1.176 | 1.526 | 180 | 416.1 |
Delaware | 87.4% | 87.1% | 109.7 | 79.8 | 0.842 | 0.853 | 130.4 | 93.5 | 61.2 | 66.4 | 0.701 | 0.767 | 87.2 | 86.5 | 112.1 | 80.8 | 0.858 | 0.864 | 130.6 | 93.4 |
District of Columbia | 98.9% | 98.2% | 71.9 | 33.7 | 0.37 | 0.302 | 194.2 | 111.5 | 33.3 | 26.3 | 0.318 | 0.277 | 104.6 | 95.1 | 71.9 | 33.7 | 0.37 | 0.302 | 194.2 | 111.5 |
Florida | 84.4% | 83.7% | 172.3 | 1011.3 | 0.982 | 1.463 | 175.5 | 691.2 | 69.4 | 69.8 | 0.78 | 0.833 | 89 | 83.8 | 160 | 1012.6 | 0.929 | 1.408 | 172.3 | 719.3 |
Georgia | 87.8% | 86.1% | 342.7 | 212.4 | 1.858 | 1.668 | 184.5 | 127.3 | 133.4 | 129.3 | 1.336 | 1.291 | 99.9 | 100.2 | 300.3 | 185.2 | 1.765 | 1.544 | 170.1 | 119.9 |
Maryland | 98.7% | 98.1% | 166.2 | 260 | 0.92 | 1.16 | 180.7 | 224.2 | 66.9 | 84.2 | 0.704 | 0.84 | 95.1 | 100.2 | 156.1 | 224.6 | 0.882 | 1.055 | 176.9 | 213 |
North Carolina | 88.5% | 86.5% | 262.5 | 486 | 1.526 | 1.97 | 172.1 | 246.7 | 156.4 | 150.7 | 1.282 | 1.238 | 121.9 | 121.6 | 249.9 | 423.1 | 1.399 | 1.788 | 178.6 | 236.6 |
South Carolina | 92.2% | 92.0% | 169.8 | 302.4 | 1.512 | 1.87 | 112.3 | 161.7 | 126.5 | 114.8 | 1.289 | 1.154 | 98.1 | 99.4 | 140.4 | 274.4 | 1.197 | 1.571 | 117.3 | 174.7 |
Virginia | 30.8% | 26.5% | 292.8 | 1108.2 | 1.655 | 2.541 | 176.9 | 436.1 | 239.9 | 342.3 | 1.522 | 1.838 | 157.6 | 186.2 | 280.6 | 1103.6 | 1.561 | 2.444 | 179.8 | 451.6 |
West Virginia | 97.8% | 98.1% | 751.5 | 1003.2 | 2.353 | 2.737 | 319.4 | 366.5 | 385.7 | 543.6 | 1.871 | 2.225 | 206.2 | 244.3 | 700.4 | 850.9 | 2.1 | 2.251 | 333.5 | 378 |
East South Central | 61.5% | 62.0% | 864.3 | 392.5 | 2.408 | 2.505 | 359 | 156.7 | 186.5 | 187.8 | 1.626 | 1.691 | 114.7 | 111 | 876.2 | 393 | 2.332 | 2.332 | 375.6 | 168.6 |
Alabama | 14.3% | 14.4% | 400.2 | 231.3 | 2.281 | 2.28 | 175.4 | 101.4 | 189.5 | 198.4 | 1.481 | 1.973 | 128 | 100.6 | 380.2 | 230.1 | 1.972 | 2.151 | 192.8 | 106.9 |
Kentucky | 93.2% | 93.0% | 861.5 | 345.5 | 1.859 | 1.707 | 463.4 | 202.4 | 140.6 | 151.5 | 1.129 | 1.278 | 124.5 | 118.6 | 841.1 | 328.1 | 1.657 | 1.525 | 507.5 | 215.2 |
Mississippi | 68.8% | 68.7% | 877.8 | 455.9 | 2.627 | 2.168 | 334.1 | 210.2 | 266.6 | 243.3 | 2.113 | 1.729 | 126.2 | 140.7 | 991.9 | 519.9 | 2.932 | 2.254 | 338.3 | 230.7 |
Tennessee | 73.2% | 74.5% | 926.9 | 428.3 | 2.803 | 3.326 | 330.7 | 128.8 | 192.7 | 194.1 | 1.891 | 1.988 | 101.9 | 97.6 | 933.4 | 425.9 | 2.773 | 3.073 | 336.5 | 138.6 |
West South Central | 64.8% | 64.8% | 685.6 | 242.8 | 1.928 | 1.775 | 355.7 | 136.8 | 163.3 | 178.3 | 1.405 | 1.498 | 116.2 | 119 | 671.2 | 238.8 | 1.784 | 1.673 | 376.3 | 142.7 |
Arkansas | 82.0% | 82.4% | 915.3 | 437.5 | 2.123 | 2.16 | 431.2 | 202.5 | 230.7 | 279.6 | 1.578 | 1.803 | 146.2 | 155.1 | 879 | 427.2 | 1.909 | 1.886 | 460.4 | 226.5 |
Louisiana | 72.3% | 74.1% | 663.2 | 323.8 | 1.881 | 1.992 | 352.5 | 162.6 | 199.3 | 252.2 | 1.501 | 1.859 | 132.8 | 135.7 | 633.7 | 306.6 | 1.759 | 1.855 | 360.3 | 165.3 |
Oklahoma | 45.9% | 45.1% | 1339.4 | 165.6 | 2.079 | 1.452 | 644.3 | 114 | 123.8 | 122.4 | 1.134 | 1.264 | 109.2 | 96.9 | 1012.7 | 141.7 | 1.713 | 1.169 | 591.2 | 121.2 |
Texas | 64.3% | 64.1% | 583.1 | 204.6 | 1.889 | 1.704 | 308.7 | 120.1 | 150.3 | 153.7 | 1.39 | 1.399 | 108.1 | 109.8 | 604.3 | 202.6 | 1.777 | 1.656 | 340 | 122.3 |
Mountain | 90.2% | 90.4% | 117.9 | 153.2 | 0.966 | 1.044 | 122 | 146.7 | 90.4 | 95.4 | 0.848 | 0.905 | 106.5 | 105.5 | 101.2 | 123.5 | 0.884 | 0.963 | 114.5 | 128.3 |
Arizona | 95.8% | 95.9% | 103.8 | 136.9 | 0.951 | 1.024 | 109.2 | 133.7 | 66.9 | 69.1 | 0.788 | 0.871 | 84.9 | 79.4 | 88.7 | 103.7 | 0.916 | 0.979 | 96.8 | 106 |
Colorado | 88.8% | 89.4% | 100.2 | 143.7 | 0.925 | 1.041 | 108.4 | 138.1 | 89.2 | 96.9 | 0.873 | 0.923 | 102.2 | 105 | 96.2 | 138.2 | 0.85 | 0.97 | 113.1 | 142.4 |
Idaho | 93.1% | 92.2% | 134.4 | 167.4 | 1.071 | 1.168 | 125.5 | 143.4 | 121.8 | 144.5 | 0.985 | 1.091 | 123.6 | 132.5 | 95.9 | 112.7 | 0.757 | 0.815 | 126.7 | 138.3 |
Montana | 68.4% | 67.9% | 113.9 | 224.7 | 1.052 | 1.398 | 108.3 | 160.7 | 113.9 | 139.6 | 1.052 | 1.214 | 108.3 | 115 | 93.9 | 187.7 | 0.852 | 1.059 | 110.2 | 177.2 |
Nevada | 102.7% | 102.6% | 138.7 | 195.1 | 0.942 | 0.984 | 147.2 | 198.2 | 81.2 | 77 | 0.745 | 0.722 | 108.9 | 106.7 | 96.9 | 424.3 | 1.131 | 1.953 | 85.7 | 217.2 |
New Mexico | 85.1% | 85.6% | 156 | 175.2 | 1.102 | 1.089 | 141.6 | 160.9 | 123.7 | 125.4 | 0.908 | 0.963 | 136.3 | 130.3 | 139 | 134.6 | 0.966 | 1 | 143.9 | 134.5 |
Utah | 85.5% | 86.7% | 127.7 | 108.7 | 0.912 | 0.858 | 140 | 126.6 | 108.5 | 96.6 | 0.866 | 0.82 | 125.3 | 117.8 | 119.9 | 103.4 | 0.919 | 0.857 | 130.4 | 120.6 |
Wyoming | 65.9% | 62.9% | 121.4 | 159 | 0.935 | 1.286 | 129.8 | 123.6 | 102.6 | 116.1 | 0.825 | 1.146 | 124.3 | 101.3 | 106.4 | 157.3 | 0.915 | 1.244 | 116.3 | 126.5 |
Pacific Contiguous | 92.8% | 92.4% | 299.1 | 246.2 | 1.295 | 1.306 | 230.9 | 188.5 | 147.8 | 152.8 | 1.035 | 1.091 | 142.8 | 140.1 | 287.3 | 232.3 | 1.215 | 1.224 | 236.5 | 189.9 |
California | 94.6% | 94.3% | 352.5 | 202.4 | 1.409 | 1.259 | 250.2 | 160.7 | 157.1 | 156.5 | 1.097 | 1.146 | 143.2 | 136.5 | 351.5 | 195.3 | 1.393 | 1.221 | 252.4 | 160 |
Oregon | 87.5% | 86.2% | 122.9 | 325.2 | 0.808 | 1.311 | 152.1 | 248.1 | 103.5 | 121 | 0.738 | 0.804 | 140.4 | 150.5 | 115.9 | 304 | 0.753 | 1.215 | 153.9 | 250.3 |
Washington | 88.0% | 87.8% | 153.8 | 403.6 | 1.05 | 1.52 | 146.5 | 265.4 | 129.8 | 153.5 | 0.915 | 0.99 | 141.9 | 155 | 113.4 | 345.6 | 0.725 | 1.24 | 156.4 | 278.8 |
Pacific Noncontiguous | 23.7% | 19.5% | 456.2 | 891.3 | 3.374 | 4.959 | 135.2 | 179.7 | 325.7 | 334.9 | 2.366 | 3.406 | 137.6 | 98.3 | 472.5 | 820.6 | 2.503 | 3.431 | 188.8 | 239.2 |
Alaska | 47.7% | 47.6% | 499.4 | 891.3 | 3.26 | 4.959 | 153.2 | 179.7 | 325.7 | 334.9 | 2.366 | 3.406 | 137.6 | 98.3 | 472.5 | 820.6 | 2.503 | 3.431 | 188.8 | 239.2 |
Hawaii | 6.9% | 248.8 | 3.922 | 63.4 | ||||||||||||||||
U.S. Total | 78.4% | 78.1% | 366.6 | 333 | 1.348 | 1.426 | 271.8 | 233.5 | 123.9 | 131.1 | 1.022 | 1.09 | 121.3 | 120.2 | 357.7 | 324.7 | 1.242 | 1.315 | 288 | 246.9 |
SAIDI = System Average Interruption Duration Index. It is the minutes of non-momentary electric interruptions, per year, the average customer experienced. SAIFI = System Average Interruption Frequency Index. It is the number of non-momentary electric interruptions, per year, the average customer experienced. CAIDI = Customer Average Interruption Duration Index. It is average number of minutes it takes to restore non-momentary electric interruptions. IEEE refers to the IEEE 1366-2003 or the IEEE 1366-2012 standard. A Major Event Day is any day that exceeds a daily SAIDI threshold called Tmed. Tmed is a duration statistic calculated from daily SAIDI values from the past five years. Loss of Supply Removed excludes outages due to loss of supply from the high-voltage/bulk power system. Percent of Customers Reported is an estimate of the percentage of total customers covered by these metrics. The numerator is reported number of meters used on the reliability schedule, while the denominator is the number of customers reported on the sales to ultimate customers schedule. It is possible, in some instances, for this metric to exceed 100%. |
For a five minute video explanation of these metrics, go to https://youtu.be/oVH9L0fCMTU. |
Source: U.S. Energy Information Administration, Form EIA-861, Annual Electric Power Industry Report. |