Southern Cross Transmission





The Southern Cross Transmission project (SCT) is an advanced-stage High-Voltage Direct Current (HVDC) bi-directional transmission line that will connect ERCOT to SERC. The 500kv, 2,000MW capacity project will allow ERCOT to access power from the southeast transmission system during times of extreme demand in Texas. The bi-directional capability of the line will also allow ERCOT to export power to southeast markets during times of excess generation and curtailments within ERCOT, bringing further stability benefits to ERCOT.


Positioned to Start Construction in 2022 

  • FERC Order to interconnect with ERCOT Transmission Service Providers already granted; FERC Order expressly maintains ERCOT’s status as exempt from FERC jurisdiction 
  • Texas PUC Certificate of Convenience and Necessity (CCN) for the transmission line to connect to SCT at the Texas border has already been issued. Process for implementing several protocol revisions to accommodate SCT interconnection is well advanced 
  • ERCOT Interconnection Agreement in place 
  • Routing study completed in Texas, underway in Louisiana and Mississippi



Benefits to ERCOT and Texas Consumers

  • Enhanced grid reliability and resilience through interconnection with robust, geographically separated southeastern grid. 
  • 2,000 MW of electricity can power about 400,000 Texas homes at peak demand
  • Benefit to ERCOT generators by providing additional outlet for power sales during surplus periods within ERCOT
  • A study conducted by Southern Cross Transmission in conjunction with ERCOT CCN process showed ~$250 million annual benefit to ERCOT ratepayers
  • Project interconnection point provides access to both Southeast and Central Regions of SERC


Transmission Experience

  • Pattern Energy team members developed, financed, and managed construction of the first and only merchant transmission line in California, the TransBay Cable (53-mi, 345kV HVDC undersea) 
  • Developed, constructed and currently operates a major merchant line in New Mexico, Western Interconnect (39-mi 345kV HVAC) 
  • Primary developer for the Southern Cross Transmission project (~400mi 500kV HVDC) from Texas to the Southeast 
  • Is currently constructing an 800 MW network line in New Mexico, Western Spirit (148-mi 345kV HVAC) for operations in late 2021 
  • Pattern Energy’s team has built hundreds of miles of high voltage gen-tie infrastructure for approximately thirty operational wind and solar facilities worldwide 
  • Primary developer for new transformative interregional lines, including the SunZia Southwest Transmission Project (500+mi 500kV HVDC) from New Mexico to Arizona and California markets