ERCOT's First 765-kV Transmission Line: A Major Step for Grid Reliability and Regional Growth

As Texas experiences rapid economic development and population growth, the state's electric grid is evolving to meet rising demand.  In a major milestone, American Electric Power (AEP) Texas is set to build one of the first 765-kV transmission lines in ERCOT, marking a historic leap forward in both transmission capacity and system reliability. 

The Howard-Solstice Project: A New Era in Texas Transmission 

On April 24, 2025, the Public Utility Commission of Texas (PUCT) approved the Howard-Solstice Line Project, one of the first 765 kV extra high voltage transmission line projects in ERCOT.  As part of the Permian Basin Reliability Plan, the project is intended to ensure that the electric grid is better prepared to meet the growing demand on Texas’s electric system.   AEP Texas will construct approximately 300 miles of 765-kV transmission, stretching from the Solstice Substation near Fort Stockton to a new substation near San Antonio. 

This effort is part of a broader push to supply more power to the Permian Basin, one of the most energy-intensive and strategically vital regions in the country.  The new extra-high voltage infrastructure will move large volumes of electricity more efficiently and reliably than the 345-kV system currently used in Texas. 

These upgrades are not just about capacity – the upgrades represent a step-change in transmission efficiency, reliability, and resilience.  They also lay the groundwork to serve growing communities and the expanding oil and gas industry in West Texas. 

Why 765-kV and Why Now? 

Though common in the U.S. Midwest and Northeast, 765-kV transmission lines are new to ERCOT.  The decision to deploy them here is a clear response to the unprecedented load growth in the Permian Basin.  This transition also aligns with Texas House Bill 5066, passed in 2023, requiring the PUCT to direct ERCOT to create a long-term reliability plan for high-growth areas. 

By using 765-kV lines, the grid can deliver more power over longer distances with fewer losses.  This helps reduce congestion, improves voltage stability, and allows for future interconnection opportunities across wider geographic areas. 

While a finalized route map for the Howard-Solstice 765-kV Transmission Line Project has not yet been released, AEP Texas has announced plans to hold open houses along the proposed route this summer.  These events will provide local community members with detailed information about potential routing options and offer opportunities to engage directly with project team members. 

Looking Ahead 

The Howard-Solstice project sets the stage for a more robust and future-ready ERCOT grid, with an increased ability to serve industrial growth, residential development, and statewide electrification. As one of ERCOT’s first 765-kV systems, it is not only historically significant, but strategically important. 

At Electric Power Engineers (EPE), we are tracking these infrastructure developments closely to help our clients anticipate grid shifts, plan ahead, and align projects with emerging transmission capabilities. 

If you are developing in the ERCOT region, it is important to understand how the 765-kV transmission may launch new possibilities for your load or generation project. Reach out below to see how EPE can support your next steps.