They are expected to add 5,729 circuit miles of transmission, ERCOT said.
Fostering demand for a major expansion are a rebounding economy, continued population growth, new electric power generation plants, and a need to transport renewable wind energy from sparsely populated West Texas to Dallas-Fort Worth and other heavily urbanized regions.
The estimated $8.2 billion in power line projects is sharply higher than the $3 billion listed in ERCOT's 2008 transmission report. That's primarily because of inclusion of $4.93 billion for new Competitive Renewable Energy Zone transmission lines, which will support 18,456 megawatts of renewable power generation primarily from West Texas and the Panhandle. ERCOT estimates peak demand in summer 2010 will be 64,056 megawatts.
ERCOT expects Texans to have plenty of power through 2013. About 3,140 megawatts of power generation has been added since May, including 1,689 megawatts from coal-fired plants and 1,093 megawatts from natural gas-fired plants. That puts supply over projected demand by at least 12.5 percent, ERCOT's minimum desired reserve margin.
The margin could narrow, however, in 2014 and beyond. ERCOT estimates a net decrease of 1,105 megawatts of generation in 2014 and 2015 as a result of excluding the big 1,792-megawatt Cobisa plant, a gas-fired power plant planned near Greenville in northeast Texas. ERCOT said project developers notified it this month "that their current projections were such that the unit should not be included in the reserve margin calculation at this time."
Potential resources not included in ERCOT's generation total include more than 3,000 megawatts of capacity that are mothballed but could be returned to service.