News Release

    December 30, 2010

    ERCOT Releases Annual Transmission Planning Reports

    Nearly $2 billion in transmission improvements completed since 2009; up to $9 billion in projects to maintain reliability and improve grid efficiency under review

    The Electric Reliability Council of Texas, grid operator and manager of the electric market, is reviewing transmission projects for the next five years which could add nearly 8,000 miles of transmission to the grid, according to the 2010 transmission report filed today with the Public Utility Commission. 

    The annual Electric System Constraints and Needs Report identifies existing and potential constraints in the transmission system that pose reliability concerns or may increase costs to the electric power market and Texas consumers.   The Long-Term System Assessment , filed in conjunction with the transmission report provides a 10-year outlook of transmission needs.

    Transmission projects up to $9 billion under review

    Up to $9 billion in projects to maintain reliability and improve grid efficiency are under review, which could add an estimated 7,866 circuit miles of transmission and 27,026 megavolt amperes (MVA) of autotransformer capacity to the grid.  The planned projects include the Competitive Renewable Energy Zones (CREZ) transmission additions that are planned to be in service by the end of 2013. 

    Aside from the CREZ transmission additions, the largest projects planned through 2015 include three new 345-kilovolt (kV) lines totaling 368 miles.  

    Weather Zone

    Major Planned Improvements



    Circuit Miles

    South Central

    Zorn/Clear Springs-Gilleland Creek-Hutto Switch line addition


    345 kV



    Zenith-Fayetteville line addition


    345 kV



    Bell County East-TNP line addition


    345 kV


    Completed transmission improvements total $2 billion

    In addition to the five-year outlook, the report reviews transmission improvements completed since 2009.  These totaled 1,933 circuit miles of transmission and 12,299 MVA of autotransformer capacity with an estimated cost of $2 billion.  The largest projects were two new 345-kV lines completed in 2010, including a 114-mile line in the south zone and a 74-mile line in the south central zone. 

    Weather Zone

    Major Completed Improvements



    Circuit Miles


    Lobo to San Miguel new line


    345 kV


    South Central

    Hutto Switch to Salado Switch new line


    345 kV



    Bowman-Jacksboro Switch line rebuild


    345 kV



    Abilene South-Putnam Line upgrade


    138 kV


    Far West

    Big Spring-Chalk-McDonald line rebuild


    138 kV



    Congestion costs lowest since 2002

    The report also analyzes historic congestion costs – the cost incurred when more expensive generation is deployed to resolve transmission overloading or imbalance and maintain electricity flows within safe operating limits. Congestion costs in 2010 were the lowest they have been since 2002.

    Long-Term System Assessment takes 10-year view

    The Long-Term System Assessment, which takes a 10-year view of transmission needs, does not provide specific recommendations but is intended to inform the five-year planning process by providing a longer term view of system reliability needs and  indicating system needs that require solutions that will take longer than five years to implement. 

    The study consisted of two parts: an analysis of the reliability needs of the system based on peak-load system conditions; and an evaluation using scenario analysis of the cost-effectiveness of potential economic projects to improve system efficiency. 

    The conclusions in the assessment included:

    • While numerous transmission system upgrades will be needed due to expected load growth over the next 10 years, particularly in the Dallas-Fort Worth and Houston areas, the analysis showed few, incremental  long-lead-time projects to be warranted;
    • There is a potential need for new transmission import capacity into the Houston metropolitan area;
    • Load growth in areas north and west of Dallas may require additional transmission infrastructure in the next 10 years. 

    As the transmission planning authority for the region, ERCOT works with the region’s transmission and distribution providers and other stakeholders to identify the need for new transmission facilities based on engineering analysis of operational results, load forecasting, generation interconnections, and transmission and system studies.  As part of the planning process, ERCOT seeks input from all market participants and stakeholders about options and possible solutions through the ERCOT-led Regional Planning Group.  Major projects must be also be endorsed by the ERCOT Board of Directors.  


    In the ERCOT region, the cost for transmission construction and upgrades is rolled into costs that all ratepayers pay – also known as a “postage-stamp transmission rate” because it is the same access fee regardless of location.  Transmission and distribution providers must offer access to their wires to all electric providers on a non-discriminatory basis.  The Public Utility Commission regulates transmission and distribution providers and approves the rates they are allowed to charge for the delivery of power to retail customers. 

    • 40,530 miles of high-voltage transmission, including:
      • 9,249 miles of 345 kV
      • 19,565 miles of 138 kV
      • 11,715 miles of 69 kV
    • $9 billion under development in five-year plan, including approximately $5 billion to support 18,456 MW of renewable generation
    • More than 8,000 circuit miles of transmission improvements since 1999
    • Approximately $6 billion in transmission improvements added since 1999

    The Electric Reliability Council of Texas (ERCOT) manages the flow of electric power to more than 25 million Texas customers -- representing about 90 percent of the state’s electric load. As the independent system operator for the region, ERCOT schedules power on an electric grid that connects more than 46,500 miles of transmission lines and 600+ generation units. It also performs financial settlement for the competitive wholesale bulk-power market and administers retail switching for 7 million premises in competitive choice areas. ERCOT is a membership-based 501(c)(4) nonprofit corporation, governed by a board of directors and subject to oversight by the Public Utility Commission of Texas and the Texas Legislature. Its members include consumers, cooperatives, generators, power marketers, retail electric providers, investor-owned electric utilities, transmission and distribution providers and municipally owned electric utilities.