(The Center Square) — The Midcontinent Independent System Operator is facing sharp criticism from Louisiana regulators following a presentation on Wednesday on last month’s emergency load-shedding event in New Orleans, which left parts of the city without power for four hours.
Public Service Commissioner Eric Skrmetta told The Center Square that MISO would soon receive subpoenas and be required to provide data and further testimony on their decision. The District 1 commissioner suggested the organization’s failure to interrupt industrial load, as required by protocol, may constitute a violation.
“See you in August,” Skrmetta said on Wednesday before making a motion to adjourn.
MISO officials, who oversee grid reliability across 15 states, described the May incident as the result of a combination of circumstances, including critical outages and transmission constraints during what is known as the “shoulder season,” when utilities schedule planned maintenance to prepare for summer peak demand.
“We understand this was deeply frustrating and disruptive,” a MISO official told Louisiana’s Public Service Commission. “But we were dealing with a unique set of reliability circumstances.”
Skrmetta was particularly critical of MISO officials, accusing them of mismanaging the situation and failing to follow procedure. Skrmetta said the grid operator ignored established steps — such as calling on large industrial users with interruptible service contracts to curtail usage — before cutting power to retail customers.
“If I’m giving industrial customers discounts to be interrupted, and they’re not being interrupted, why am I giving them those discounts?” Skrmetta asked. “You took your eye off the ball.”
According to MISO, four generation units — totaling approximately 2,600 megawatts — had been undergoing planned outages since March, all of which had been studied and approved. Another eight units, accounting for nearly 4,000 megawatts, were forced offline due to unplanned issues between April and May 25.
Compounding the situation, a major transmission line near the Waterford plant had been out since March due to tornado damage, creating what MISO described as a “load pocket” in the New Orleans area — a region with limited ability to import or export electricity.
As temperatures climbed over the Memorial Day weekend, MISO said grid models triggered an “Interconnection Reliability Operating Limit” event, requiring immediate action to avoid a widespread system collapse.
“We are required to resolve IROL violations within 30 minutes,” officials said, referencing the federally mandated reliability protocol created in the wake of the 2003 Northeast blackout.
MISO defended its actions, saying that decisions were made under pressing circumstances.
