Table 8.10.B. Proposed Transmission Capacity Additions by High-Voltage Size, 2013 - 2019
(Circuit Miles of Transmission)
 

Voltage Circuit Miles
Type Operating (kV) Year 2013 Year 2014 Year 2015 Year 2016 Year 2017 Year 2018 Year 2019 All Years
AC 100-199 954 1,222 992 1,047 392 382 176 5,165
AC 200-299 1,003 792 1,398 319 539 427 118 4,596
AC 300-399 4,779 839 1,532 1,527 502 1,650 349 11,178
AC 400-599 399 708 669 643 660 1,151 334 4,564
AC 600+ -- -- 14 -- -- 69 -- 83
AC Total   7,134 3,562 4,606 3,536 2,092 3,679 978 25,586
DC 100-199 2 11 5 -- -- 7 -- 25
DC 200-299 -- -- -- -- -- -- -- --
DC 300-399 -- -- -- -- 333 -- -- 333
DC 400-599 -- -- 10 -- -- -- -- 10
DC 600+ -- -- -- -- -- -- -- --
DC Total   2 11 15 -- 333 7 -- 368
Grand Total   7,136 3,573 4,621 3,536 2,425 3,687 978 25,955

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."