National High-Voltage Transmission Interconnect Project Continues to Face Support and Financing Hurdles
The proposed Tres Amigas interconnection has been viewed as a critical development for establishing solid superconducting high-voltage direct current (HVDC) linkages between the three primary transmission networks in the United States. These networks include the Western Electric Coordinating Council (WECC), ERCOT, and the Eastern systems. The project is thought to be critical to maintaining reliability and connecting the tremendous wind and solar renewable energy resources in the upper Midwest and the Southwest, with the urban population centers in the Central Midwest and the East. The project has been in planning and early development stages since 2008, and it has struggled to get approximately $1.6 billion in funding for a highly technical project that involves large scale high-voltage alternating current transmission lines (HVAC) to HVDC lines necessary for synchronization of the three systems. It also incorporates re-conversion to HVAC at the interconnect points with the other networks.
In late July, the Federal Energy Regulatory Commission (FERC) announced that it had approved a request from the Southwest Power Pool (SPP) to void an interconnection agreement between Tres Amigas and Southwestern Public Service (SPS), primarily based on Tres Amigas missing multiple payments and a number of performance milestones. While the missed payments are a small portion of the total $1.6 billion dollar project, partnerships with adjacent transmission operators are critical to the completion of the project.
In previous Navigant Research blogs, I have discussed the development of a north-south transmission highway between the northern Midwest wind farms, the utility scale solar in the Southwest, and the population centers in Nebraska, Kansas, and Texas. Interestingly, the SPP transmission plans I saw show that this conceptual idea is beginning to come to fruition as new 345 kV transmissions systems are being built and older systems are upgraded. Many of these projects have been completed by the transmission owner/entities in the region to address congestion issues in corridors like the Omaha/Kansas City to the Texas Panhandle route.
Anticipating Coal Plant Retirements
However, coal plant retirements across the lower Midwest, East Coast, and southeastern United States will have a serious impact on electric reliability across those regions, according to the North American Electric Reliability Corporation (NERC). Forward-thinking electric transmission companies are anticipating this and are now building new West-to-East transmission to deliver wind power from the High Plains to population centers in the Midwest and Southeast that will be hit hard by the retirements. The Tres Amigas interconnection may be a critical part of the puzzle that is the modernization of the national versus regional transmission grids. While Navigant Research expects that it will ultimately be funded by numerous transmission utilities, the full funding for the multi-billion dollar project has yet to fall into place.
You can read more about the Tres Amigas project and HVDC transmission systems in my syndicated reports, including High-Voltage Transmission Systems and High-Voltage Direct Current Transmission Systems.