Sharyland’s High Voltage Direct Current Tie (DC Tie) was originally commissioned into service in October 2007 as a 150 megawatt (MW) transmission interconnection located along the Rio Grande border near the cities of Mission, Texas, and Reynosa, Tamaulipas, Mexico. This DC Tie links the ERCOT grid with the Mexican national grid, operated by the Centro Nacional de Control de EnergÍa (CENACE).

Sharyland’s open-access, cross-border DC Tie was the first of its kind to support commercial business activity and to provide emergency power from either Texas or Mexico. Its technology allows for a bi-directional flow of electricity between both grids, allowing each grid to rely on the other in times of peak demand. Not only does this strengthen the stability of both grids, but it has also fostered an international wholesale market that brings together power generators and commercial customers on both sides of the border.  

In July 2014, Sharyland expanded the capacity of its DC Tie from its initial 150 MW to 300 MW, adding additional reliability support and allowing for future economic growth in the region.  

The Cross Valley Project is a perfect example of Sharyland’s creativity and willingness to work with local partners and neighboring electric providers to meet regional needs. 

In 2009, Sharyland Utilities began working with the city of Brownsville’s Public Utilities Board (BPUB) to develop a solution that would improve the reliability of the transmission system in the Brownsville area and, more broadly, the Lower Rio Grande Valley of Texas.  

Initially, the need for the project was not apparent, as ERCOT and neighboring utilities argued that a new line couldn’t be justified until a large load committed to locate in the region. However, in January 2011, as extreme cold weather affected energy-generating resources throughout the state and resulted in rolling blackouts, the Rio Grande Valley was hit especially hard and needed one of our DC Ties (high-voltage direct current power transmission lines) to help import power from Mexico. This event confirmed the need for the Cross Valley Project in the region to address different reliability and security risks in the region.

Endorsed by ERCOT in 2012 and approved by the PUCT in 2014, the Cross Valley Project consisted of a new 96-mile 345kV transmission line that runs from Edinburg to Brownsville. Sharyland constructed the eastern half of the line, while Electric Transmission Texas, a neighboring transmission provider, constructed the western half. In the summer of 2016, construction was completed and the line was finally energized.  

Competitive Renewable Energy Zones (CREZ) are specific areas in West Texas and the Panhandle that have been identified as resource-rich, high-wind areas. Established by the Texas Legislature in 2005, CREZ connects highly populated parts of the state with abundant wind resources.  

In 2006, Sharyland Utilities became an active participant in the CREZ process. Sharyland and Hunt Power saw CREZ as an opportunity to address the growing needs of electric infrastructure in the South Plains and greater Texas Panhandle regions, located over 700 miles from their original service territory in South Texas. As an innovative solution, Sharyland worked with a diverse group of renewable and traditional generators (who agreed to serve as anchor tenants) to file a proposal called the “Panhandle Loop” with the Public Utility Commission of Texas (PUCT).  

Ultimately, while the PUCT did not select our “Panhandle Loop” proposal, Sharyland Utilities was designated in 2009 to construct approximately 300 miles of new 345 kV CREZ electric transmission facilities, including four collection stations, throughout the Texas Panhandle and South Plains. By late 2013, Sharyland had completed its portion of the CREZ buildout both on time and under budget. Golden Spread Electric Cooperative, with their set of natural gas-fired peaking plants, was one of the first generators seeking to interconnect with our new CREZ lines – a possibility envisioned in the “Panhandle Loop” proposal. Hunt and Sharyland’s creative approach helped ensure that the CREZ process included the Texas Panhandle and South Plains, two regions with the best wind resources in the state!  

As part of Hunt’s acquisition of Cap Rock Energy in 2010, Sharyland agreed to file a plan with the Public Utility Commission of Texas (PUCT) to physically disconnect Sharyland’s newly acquired West Texas system from the Southwest Power Pool (SPP) and reconnect it to ERCOT no later than December 31, 2013. The PUCT approved the plan in the summer of 2011, and it took Sharyland another two and a half years to prepare for the migration of its entire West Texas transmission and distribution system to ERCOT, including a 320-mile 138kV transmission loop. The migration was completed on December 21, 2013.   

Because migrating customers from one grid to another requires the interruption, or “disconnection,” of service, the Sharyland team scheduled the transition to occur in stages. This ensured that all customers were not affected at the same time and that localized outages only lasted a few hours each. In addition, Sharyland rebuilt nearly all of the 320 miles of lines to serve the expansion needs of the Permian Basin, due to the demand for electricity tripling in under five years! Ultimately, Sharyland added new 345kV stations and interconnections, created more redundancy and reliability, and even connected several renewable plants along the way.    

Throughout its history, Hunt has proposed projects that address regional transmission needs across Texas. One notable proposal involved Lubbock Power & Light (LP&L), a municipally owned utility previously connected to the Southwest Power Pool (SPP) rather than to ERCOT.  

Anticipating the end of their power contract in 2019, LP&L initiated the RFP (request for proposal) process in 2014 to seek next-generation solutions for meeting their power needs. Sharyland recommended a transmission solution, rather than a generation solution, to connect LP&L to ERCOT. This would allow LP&L to access lower prices and a more robust power supply market in ERCOT, expanding Sharyland’s transmission network and allowing for more wind to be developed in the Panhandle region.  

LP&L embraced Hunt’s idea and, in November 2015, officially started the process to formally join the Texas grid. In March 2018, the Public Utility Commission of Texas (PUCT) approved the plan and designated LP&L and Sharyland to build the transmission facilities necessary to connect LP&L’s system to ERCOT. To further strengthen LP&L’s migration, Sharyland supported the initial review by PUCT and ERCOT of more than $300 million in transmission additions. In May 2019, shortly after completing the design, defining routes, and filing construction licenses, Hunt sold the project to Oncor as part of a larger InfraREIT transaction. LP&L successfully migrated its customers from Southwest Power Pool to ERCOT in June 2021. 

These efforts with LP&L are only a continuation of what Hunt has always done: to propose innovative solutions to areas with critical infrastructure needs and to work with local utilities to make proposals like these a reality. Both demand and generation customers have benefitted greatly from these efforts with a power service that is not only adjacent to the large wind and solar development but also more reliable and affordable.