Grid modernization helps crews restore power quickly after storms

Two separate sections of Great River Energy transmission line sustained damage over the course of a week of severe weather, but recent grid modernization efforts allowed power to be restored quickly with minimal disruption to members.

Straight line winds on July 31 downed more than a dozen structures on a 69-kilovolt (kV) transmission line spanning approximately one mile near Zumbrota, Minnesota. Great River Energy has motor-operated switches along the line which allow system operators in the control center located an hour away to remotely open and close transmission switches quickly to sectionalize damaged line sections.

Because of this capability, there was only a six-minute outage to a Goodhue County Electric Cooperative distribution substation. With electricity being routed elsewhere, Great River Energy line crews were able to safely complete their work on the damaged line.

“We had excellent work by the crews, line engineering, procurement and system operations to get this line with 15 damaged structures restored safely in less than 48 hours,” said Jonathan McGuire, supervising manager of transmission construction and maintenance at Great River Energy.

Just a few days later, on Aug. 3, storms rolled through again and downed four structures on the 69-kV Cedar Mills tap line near Hutchinson, Minnesota. McLeod Cooperative Power, Kandiyohi Power Cooperative and Meeker Cooperative Light and Power member-owners experienced sustained outages on eight distribution substations.

Again, using motor operated switches, four of the eight distribution substations were returned to service within three minutes. Meeker’s Cedar Mills distribution substation experienced the longest outage of just over three hours. Great River Energy’s transmission team responded quickly that weekend and had the transmission line back in service by the next day.

“We had great teamwork to get these structures restored quickly,” said Darin Orbeck, supervising manager of transmission construction and maintenance at Great River Energy.

Great River Energy already has 134 motor operated switch sites located strategically on its load serving transmission system, and the cooperative has plans to add more in the years ahead.

At Great River Energy, resilience is a journey that is never complete. The cooperative is always looking for ways to improve and continuously strives to seek improvement opportunities with a focus on resilience.