SPP’s Statement on the April 26 Load Shed Event in Northwest Louisiana
Southwest Power Pool (SPP) is a grid operator responsible for maintaining electric reliability across a 14-state region in the central U.S., including SWEPCO’s service territory. On Saturday, April 26, SPP identified instability on the grid in the Northwest Louisiana area and directed SWEPCO to immediately reduce its electricity use by 140 MW to prevent more widespread impacts. This directive resulted in the immediate loss of power for approximately 30,000 customers, primarily in Caddo and Bossier Parish, for approximately six hours. Although this step mitigated the risk of cascading outages that would have resulted in the loss of approximately 2,000 MW, putting hundreds of thousands of customers in the dark for a longer period, SPP acknowledges and regrets the burden this preemptive action put on many of SWEPCO’s customers.
The April 26 outage was not a direct result of record electricity consumption, but resulted because in the preceding days, some generators and transmission lines in the SWEPCO area were either taken or left out of service for planned maintenance. SPP and its member utilities – including SWEPCO – carefully coordinate planned maintenance outages far in advance based on the best forecast data available at the time. SPP’s forecasts did not identify the need for these facilities to be brought back into service in time to mitigate issues that arose on April 26.
SPP ultimately deemed the April 26 service interruption to be necessary in response to rapidly developing voltage instability on transmission lines in and around Caddo and Bossier Parish. Emergency protocols dictated that local electricity use be curtailed to prevent a cascading system collapse that would have impacted a wider area. As the local utility, SWEPCO was required to follow SPP’s instructions and maintain the controlled outage until SPP determined the system was no longer at risk.
In more than eight decades of experience managing regional grid reliability, SPP has only ever used controlled interruptions as a last resort and as required under certain circumstances by federal reliability standards. Also known as “load shed”, this step is taken to prevent an uncontrolled blackout that could be longer-lasting, more widespread and more difficult and costly to recover from.
We sincerely regret this action was needed and the negative impact it had on SWEPCO customers. SPP remains committed to ensuring regional reliability through all available means. We underscore that service interruptions are only ever used as a last resort and acknowledge the impact our actions have on consumers. We will work with SWEPCO to perform a comprehensive analysis of this event to understand its drivers and assess what is needed in the future to ensure the continuous delivery of wholesale electricity. We will consider all possible solutions to issues that threaten real-time and long-term reliability across the region we serve.