“…PJM Interconnection and the Midcontinent Independent System Operator (MISO), for example, were able to adjust their systems and export power to other regional power grids during the storm, said Devin Hartman, director of energy and environmental policy at the R Street Institute.

PJM and MISO are regional transmission organizations (RTOs), which manage electric reliability and facilitate the development of regional transmission lines. The two grid operators’ territories stretch across more than 20 states in total.

Overall, PJM and MISO showed “superior performance” compared to the Southeast during the winter storm that occurred on Dec. 24, said Hartman, whose think tank advocates for free markets and limited government.

“Winter Storm Elliott was a good initial test run for SEEM. The utilities in the Southeast region are supposed to be able to share excess supplies on SEEM,” Hartman said. “When Elliott hit, the buying opportunities on SEEM disappeared…”