Southeastern Regional Transmission Planning (SERTP) stakeholder meetings in 2025 have tackled Long-Term Scenario Development and surging load forecasts - but with reliability risks mounting and economic opportunities on the line, the Southeast needs more than compliance checkboxes.

It needs leadership and vision. It needs action.

Transmission inaction is already imposing real costs. Delayed and higher cost interconnection needs, higher cost local transmission upgrades, and constrained access to low-cost resources are pushing rates higher and deterring investment. 

A report released by Grid Strategies in November, conducted on behalf of WIRES, paints the full economic picture of how delays in building large-scale transmission efforts imposes significant costs on consumers by postponing or eliminating key benefits while hindering economic development, job growth and national security. 

The report's Executive Summary notes several key findings, including: 

• For every $1 billion investment in well-planned, large-scale transmission that is delayed, it costs consumers approximately $150 million in lost net benefits for each year of delay - these losses stem from postponed reliability improvements, reduced access to lower-cost generation and lost economic efficiencies;
• Each $1 billion of delayed transmission investment defers an estimated 11,000 to 25,000 direct, indirect and induced job-years - pointing directly to the fact that transmission projects are significant infrastructure investments that support a skilled workforce. Delays in these projects slow job creation in communities that are looking for these jobs to keep moving their economies forward.

Having a modern grid in this age of rising demand from large users like data centers and large manufacturers is more important than ever. Polling released in September by the Conservative Energy Network (CEN) found broad public support in three MISO states for investing in America’s electric transmission grid to boost reliability, lower costs, spur economic growth in communities, and meet future power needs. Recent elections in Georgia, Virginia and New Jersey showed that electricity affordability has become a top priority for voters.

Scenario-based planning is essential for long-term regional transmission planning because it enables utilities and planners to prepare for a range of plausible futures rather than betting on a single forecast. By modeling diverse scenarios—such as varying levels of electrification, clean energy adoption, expected power plant retirements, or economic growth—planners can identify transmission investments that perform well across multiple outcomes like high-impact extreme weather events that occur over time. This reduces the risk of overbuilding or underbuilding and ensures that the grid remains reliable, affordable, and adaptable under changing conditions.

Essentially, it helps to “future proof” the grid.

Much of the discussion at the Q1 SERTP meeting focused on baseline scenarios; however, all scenarios are expected to only evaluate 20-years worth of forecasts. And while this is a significant improvement over SERTP’s current 10-year outlook, it falls well short of some of its industry peers.

Southwest Power Pool, for example, uses a 40-year horizon for long-term planning.

Stakeholders at the Q2 meeting were presented with 10-year forecasts for elements that influence transmission solutions. Things like demand, or ‘load forecast,’ play a large role in identifying the transmission needed to serve consumers throughout the SERTP footprint.

And SERTP's Q3 meeting provided the results of the Economic Planning Studies proposed by the Regional Planning Stakeholder Group. The report identifies potential transmission enhancements within the SERTP footprint. 

Increased demand is driven by large data center companies which have presented increasing challenges across the footprint, and a need for additional generation as well as transmission resources.

To accommodate this load forecast, Southern Company (SOCO), Duke Energy and the Tennessee Valley Authority (TVA) all have significant additions of solar and battery energy storage capacity. There are also commitments to building new natural gas generation. Demand has increased dramatically for new natural gas turbines, and with this increase in demand comes an increase in wait times - recent studies report that gas turbine supply chain delays could run up to 7 years, which would delay these in-service dates.

When this generation comes online, it becomes a big factor in what transmission needs to get built. How power moves across the grid, and when it’s available can drive drastically different transmission solutions.

In April, SREA released a report from The Brattle Group that showed the Southeast faces up to 20 GW of new load and 80 GW of new generation by 2035, yet the region hasn’t approved a single regionally-planned transmission project in more than a decade.

Proactive, scenario-based transmission planning isn’t a bureaucratic requirement—it’s an economic imperative.

If we are proactive and plan for the future now, we will reap the benefits. If not, our future will be economic losses and power outages. The choice is simple.

The SERTP Q4 meeting will be held on December 11, 2025. Registration for the meeting has already closed. As we approach the new year, urge your Southeast decision makers and regulators to prioritize proactive transmission planning before rising demand outruns our infrastructure by adding your voice here.