Holistic regional transmission planning in the Southeast is essential to reducing greenhouse gas emissions from electricity by 2030, reducing customer bills by using resources more efficiently across a larger region, and maintaining or improving the reliability of the current electric grid. Regional transmission improves utilities’ access to surplus renewable energy from their neighbors. In the face of a changing electric grid, Southeastern utilities need transmission planning that looks at the entire region when establishing benefits in lieu of inefficient and unnecessarily costly local upgrades for their customers. For this reason, SACE is an active stakeholder at the quarterly meetings for Southeastern Regional Transmission Planning (SERTP).

In previous reporting, SACE and other advocates have highlighted SERTP’s shortcomings, specifically detailing how Order 1920 is part of a necessary shift away from a process that studies regional transmission lines to justify not building them. Compliance with Order 1920 for SERTP is still several years away, and involvement in the current annual SERTP process is essential to addressing immediate and long-term energy constraints across the Southeast.

Alabama Power hosted SERTP’s Q1 2025 meeting in Birmingham, Alabama, on March 25. SERTP meetings are hosted by one of SERTP’s member utilities, and representatives from all SERTP members are present. This meeting saw robust participation from clean energy advocates, consumer advocates, public service commission staff, clean energy developers, and electric cooperatives.

Prior to the meeting, SACE used SERTP’s annual Public Policy Study request process to, once again, ask the regional group to study the potential for regional transmission needs driven by North Carolina legislation HB 951, also known as the North Carolina Carbon Plan. Duke has sought to delay compliance with HB 951 by insisting on using resources within its service territory. SERTP has not carried out an examination of regional resources to achieve this target despite requests from multiple stakeholders over the last three years. As the developer of annual region-wide transmission models, SERTP is the appropriate venue for a public policy study.

However, SERTP, which includes both Southern and Duke, rejected a SERTP public policy study of HB 951, claiming that since the 2024 Carbon Plan Integrated Resource Plan approved by the North Carolina Utilities Commission did not identify any off-system resources to meet system needs, HB 951 does not drive a regional transmission need. Furthermore, absent instruction from a state public service commission, SERTP utilities will not spend money from their customers’ electric bills to study transmission that would be used to import outside resources that, in their judgment, are not cheaper than generation and transmission within their own system.

Clean energy and consumer advocates attending disagreed with this assessment. Until SERTP does a study, we cannot know for sure that regional resources would be more expensive to Duke customers.

When looking at a wide range of reliability and public policy benefits, regional transmission solutions tend to be more economical than managing the new electric generation in the Carolinas with only local upgrades. Utility-integrated resource plans, the data that SERTP aggregates for their regional planning, are written by utilities, which gives them wide discretion to document the cost of generation and transmission to regulators. As a result, integrated resource plans do not, on their own, provide regulators sufficient data to show that regional transmission projects and the imported energy they can bring into a service area are more cost-effective than a utility’s local selection of generation and transmission.

Furthermore, since SERTP’s Order 1000 process began in 2015, SERTP has not carried out any public policy studies. A review of rejected studies over the past ten years shows utilities citing a lack of an enacted state or local law, the public policy requirement not yet included in an approved utility integrated resource plan, or the public policy requirement only effects local generation and transmission, but not regional power flows.

SACE did not withdraw our public policy request, but we agreed with Duke and Southern to separately submit the regional transmission projects between systems as economic study requests. This isn’t the best approach for understanding the effect of public policy on regional transmission. At SERTP, economic studies are narrow. SERTP will only do five economic studies each year without additional cost to the requester.

However, once we moved to economic studies in the meeting agenda, the utilities and other stakeholders collaborated to adjust economic studies in order to maximize opportunities to identify potential regional projects, including three transfers to the Carolinas as a small slice of what a public policy study for the Carbon Plan would look like. One change in how SERTP utilities perform economic studies is the potential to look at scaling load in one location instead of scaling load evenly across an entire utility service territory.

The Southeast continues to face new challenges to its electric grid, including load growth and extreme weather that will become even more intense as the planet continues to warm from greenhouse gas emissions. Regional transmission is essential to improve reliability, avoid saddling customers with unnecessarily expensive local power plants, and reduce the use of fossil fuels to produce electricity. The SERTP process remains extremely limited, and consistent participation from utility commission staff, regulators, retail cooperatives, developers, and large customers is essential to improve regional planning to address a transforming grid. The next SERTP meeting will be on June 25 in Chattanooga, Tennessee. The agenda and registration will be posted on the SERTP website. We hope to see you there!

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Regional Transmission Planning Update: Reliable, Affordable Energy Needs More Work