| Table 8.10.A. U.S. Existing Transmission Capacity by High-Voltage Size, 2011 |
| Voltage | Circuit Miles | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Type | Operating (kV) | FRCC | MRO | NPCC | RFC | SERC | SPP | TRE | WECC | Contiguous U.S. |
| AC | 100-199 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| AC | 200-299 | 5,964 | 7,765 | 1,548 | 6,954 | 21,433 | 2,872 | -- | 37,488 | 84,023 |
| AC | 300-399 | -- | 11,592 | 4,981 | 13,637 | 3,640 | 5,093 | 9,645 | 10,437 | 59,025 |
| AC | 400-599 | 1,201 | 473 | -- | 2,637 | 8,894 | 94 | -- | 12,905 | 26,204 |
| AC | 600_799 | -- | -- | 190 | 2,226 | -- | -- | -- | -- | 2,416 |
| AC Multi-Circuit Structure | 200-299 | 1,154 | 60 | 36 | 2,001 | 4,102 | 9 | -- | 5,315 | 12,677 |
| AC Multi-Circuit Structure | 300-399 | -- | 773 | 274 | 3,296 | 155 | 153 | 2,708 | 233 | 7,591 |
| AC Multi-Circuit Structure | 400-599 | -- | -- | -- | 90 | 631 | -- | -- | 592 | 1,312 |
| AC Multi-Circuit Structure | Mixed Voltages | -- | 57 | 28 | 9 | 27 | -- | -- | 194 | 315 |
| AC Total | US Total | 8,319 | 20,721 | 7,057 | 30,849 | 38,881 | 8,220 | 12,353 | 67,165 | 193,564 |
| DC | 100-199 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC | 200-299 | -- | 930 | -- | -- | -- | -- | -- | 53 | 983 |
| DC | 300-399 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC | 400_499 | -- | 872 | -- | -- | -- | -- | -- | -- | 872 |
| DC | 500_599 | -- | -- | -- | -- | -- | -- | -- | 2,137 | 2,137 |
| DC | 600_799 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC Total | US Total | -- | 1,802 | -- | -- | -- | -- | -- | 2,190 | 3,991 |
| Grand Total | Grand Total | 8,319 | 22,522 | 7,057 | 30,849 | 38,881 | 8,220 | 12,353 | 69,354 | 197,555 |
| Voltage | Circuit Counts | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Type | Operating (kV) | FRCC | MRO | NPCC | RFC | SERC | SPP | TRE | WECC | Contiguous U.S. |
| AC | 100-199 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| AC | 200-299 | 402 | 187 | 65 | 572 | 1,278 | 130 | -- | 1,432 | 4,065 |
| AC | 300-399 | -- | 189 | 232 | 485 | 116 | 112 | 295 | 143 | 1,572 |
| AC | 400-599 | 19 | 2 | -- | 78 | 226 | 1 | -- | 218 | 544 |
| AC | 600_799 | -- | -- | 2 | 32 | -- | -- | -- | -- | 34 |
| AC Multi-Circuit Structure | 200-299 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| AC Multi-Circuit Structure | 300-399 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| AC Multi-Circuit Structure | 400-599 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| AC Multi-Circuit Structure | Mixed Voltages | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| AC Total | US Total | 421 | 378 | 299 | 1,168 | 1,620 | 243 | 295 | 1,792 | 6,216 |
| DC | 100-199 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC | 200-299 | -- | 2 | -- | -- | -- | -- | -- | 1 | 3 |
| DC | 300-399 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC | 400_499 | -- | 2 | -- | -- | -- | -- | -- | -- | 2 |
| DC | 500_599 | -- | -- | -- | -- | -- | -- | -- | 4 | 4 |
| DC | 600_799 | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| DC Total | US Total | -- | 4 | -- | -- | -- | -- | -- | 5 | 9 |
| Grand Total | Grand Total | 421 | 382 | 299 | 1,168 | 1,620 | 243 | 295 | 1,797 | 6,225 |
| Notes: NERC region and reliability assessment area maps are provided on EIA's Electricity Reliability web page: http://www.eia.gov/cneaf/electricity/page/eia411/eia411.html Circuit miles do not equal physical miles on the ground; the reference terminology for that concept is structural mile. Source: U.S. Energy Information Administration, Form EIA-411, "Coordinated Bulk Power Supply and Demand Program Report." |