Market Information System Grid and Market Conditions

News Release

April 02, 2008

ERCOT Files Wind Transmission Options with Commission

The Electric Reliability Council of Texas, Inc., filed a 115-page transmission study with the Public Utility Commission (PUC) today, which provides transmission plans for four scenarios of wind generation ranging from 12,000-24,000 megawatts (MW). 

Texas Senate Bill 20 (2005) directed the Public Utility Commission (PUC) to designate Competitive Renewable Energy Zones (CREZs), after consultation with ERCOT and Southwest Power Pool, in areas with sufficient renewable resource potential and financial commitment from developers and to designate a plan for transmission to the areas.  The PUC issued an interim order in July 2007 designating CREZs in five areas of the Panhandle and West Texas.  The PUC directed ERCOT to perform optimization and reliability studies and recommend a transmission plan for four different levels of wind capacity from the designated zones. 

The transmission optimization study evaluated a variety of transmission solutions and hundreds of individual plans, using three overarching criteria: system reliability, sufficient transfer capacity, and how “beneficial and cost-effective to consumers” each plan would be. 

The estimated costs, excluding collection costs, of the transmission proposal that best meets the criteria for each are:

  • Scenario 1, Plan A, 12,053 MW, $2.95 billion
  • Scenario 1, Plan B, 12,053 MW, $3.78 billion
  • Scenario 2, 18,456 MW, $4.93 billion
  • Scenario 3, 24,859 MW, $6.38 billion
  • Scenario 4, 24,419 MW, $5.75 billion.

While Plan A is the least expensive, ERCOT noted that Plan B can be expanded more cost-effectively to the larger wind scenarios. 

Each scenario includes 6,903 MW of existing wind generation (in service or with interconnection agreements as of fall 2007).  


In ERCOT’s deregulated market, transmission and distribution providers are still regulated by the Public Utility Commission.  The cost of transmission is “uplifted to load;” it is rolled into costs that all ratepayers pay (also known as a “postage-stamp” transmission rate because – like stamps – it’s the same access fee no matter where the location is). 

 “Collection costs” refers to the estimated cost of equipment to connect the wind generation to the new CREZ facilities.  The costs are based on assumptions of average length of transmission lines from the wind facilities to the collection substation (10 Miles); average amount of wind generation on each new circuit, and voltage level for lines connecting the wind farms to the collection substation.

The Electric Reliability Council of Texas (ERCOT) manages the flow of electric power to more than 26 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 710+ generation units. It also performs financial settlement for the competitive wholesale bulk-power market and administers retail switching for nearly 8 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.