Table 8.10.B. Proposed Transmission Capacity Additions by High-Voltage Size, 2012 - 2018
(Circuit Miles of Transmission)
 

Voltage Circuit Miles
Type Operating (kV) Year 2012 Year 2013 Year 2014 Year 2015 Year 2016 Year 2017 Year 2018 All Years
AC 100-199 1,470 1,412 1,370 504 530 261 421 5,967
AC 200-299 1,038 658 641 1,027 237 596 487 4,685
AC 300-399 1,208 5,058 1,459 650 1,157 390 1,487 11,407
AC 400-599 226 450 861 677 3,400 980 709 7,303
AC 600+ -- -- -- -- -- -- 258 258
AC Total   3,941 7,578 4,331 2,858 5,324 2,226 3,362 29,620
DC 100-199 -- -- -- -- -- -- -- --
DC 200-299 -- -- -- -- -- -- -- --
DC 300-399 -- -- -- -- 140 -- -- 140
DC 400-599 -- -- -- -- -- -- -- --
DC 600+ -- -- -- -- -- -- -- --
DC Total   -- -- -- -- 140 -- -- 140
Grand Total   3,941 7,578 4,331 2,858 5,464 2,226 3,362 29,760
Lines Taken Out of Service   -- -- -- -- -- -- -- --

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.
Some structures were designed and then built to carry future transmission circuits in order to handle expected growth in new capability requirements.
Lines are taken out of service for a variety of reasons including intentional changes to the right-of-way to better useavailable land for different levels of voltage and types of poles and towers.
Source: U.S. Energy Information Administration, Form EIA-411, "Coordinated Bulk Power Supply and Demand Program Report."