A new study from GridLab and Telos Energy challenges a recent U.S. government recommendation to maintain coal plants and build new gas capacity, arguing instead that connecting a fraction of pending clean energy projects could meet growing electricity demand and improve reliability.
The report, titled “Analysis of Resource Adequacy Across the Eastern Interconnection: An Open-Source Case Study Using GridPath,” analyzed the Eastern Interconnection—covering most of the continental U.S. and parts of Canada—and focused in particular on PJM-South, a sub-region of the nation’s largest grid operator, PJM Interconnection.
Researchers found that PJM-South, which faces the highest near-term reliability risk in the region through 2028, could meet the industry-standard reliability threshold of “one day in ten years” by deploying less than one-third of its clean energy projects currently awaiting interconnection. This could be achieved without building additional natural gas capacity, while still meeting forecasted data center demand and accommodating scheduled retirements of older generating units.
“This underscores the value of accelerating the development and interconnection of clean energy resources already in the queue,” the report said.
The study also showed that PJM-South could further reduce reliability risk by enhancing regional electricity transfers. By raising its simultaneous import limit from 9 gigawatts (GW) to 13 GW, the region would still stay below the combined non-coincident import capacity of its neighboring regions, the report found.
In contrast, the U.S. Department of Energy’s (DOE) Resource Adequacy Report concluded that allowing 104 GW of firm generation to retire by 2030 without timely replacement could result in significant outages. The DOE report supports maintaining coal and gas plants and is intended to guide planning with utility stakeholders. The agency said it will regularly update its analysis based on industry feedback.
However, the GridLab/Telos study cautioned that policy efforts to extend the life of aging generation through out-of-market contracts or “reliability-must-run” agreements may be “less efficient” than accelerating the clean energy interconnection process and enhancing transmission links.
The authors emphasized that their open-source methodology provides a replicable model for resource adequacy assessments across large geographic areas and utility systems. They suggested incorporating cold-weather-driven thermal outages and fuel supply disruptions into future modeling to better account for winter reliability risks.
