Highline Electric Association Supports Members During February 2021 Cold Weather

The inherent advantages of the U.S. electric cooperative model have been known for decades. During the Feb. 13-18 Arctic cold wave that affected most of the nation, however, the Highline Electric Association in Holyoke, Colo., took the principles of cooperation among cooperatives and concern for the community to new levels.

During last month’s historic cold, Highline Electric utilized the unique configuration of its local distribution system to save fellow Tri-State Generation and Transmission Association cooperative members tied to the eastern interconnection from potential multiple controlled interruptions. 

These controlled interruptions were directed by the Southwest Power Pool (SPP) regional transmission organization and were implemented across its region including western Nebraska, during the early part of the week. The limited and brief controlled interruptions were directed as reserves tightened, in an abundance of caution to protect overall grid reliability. Tri-State had sufficient generation resources in the SPP to serve its members’ demand, but all transmission operators were directed by SPP to take part in a pro-rata share of the controlled interruptions. 

Unique Electrical Distribution Created Helpful Resources

 “Highline Electric’s distribution system is tied to both the eastern and western interconnect through several of our substations. It’s fairly unique among distribution cooperatives and investor-owned utilities in the U.S, but during the recent cold, it presented some unusual opportunities to help our fellow Tri-State members,” said Dennis Herman, Highline Electric general manager.

On a typical day, about two-thirds of Highline Electric’s 10,400 metered-customers are served on the western interconnection. Through some creative thinking, and later implementation by cooperative employees Alex Astley, Rance Ferguson, and field employees, Highline Electric on Tuesday, Feb. 16, shifted approximately three megawatts of load from its eastern interconnection to the western grid.

This action by Highline Electric met the Southwest Power Pool-directed load shed requirements in the eastern interconnection and prevented other cooperative members in Nebraska from additional controlled interruptions. During this eastern interconnection issue, there were no controlled interruptions needed in the Western Interconnection.

Once the tight supply issues subsided, Midwest Electric in Grant, Neb., was able to restore its normal operating configuration in relatively short order. The Wheat Belt Public Power District in Sydney, Neb., was called upon for a one-hour controlled interruption earlier on Tuesday but did not have to go through any more such situations through the rest of the week.

Herman noted that Highline Electric and Tri-State originally discussed the unique solution on Monday, Feb. 15, but did not have a need to implement the changeover that day. As the extreme cold continued into Tuesday, however, Highline Electric was prepared by the early morning hours to make the switch and help its fellow cooperatives, and the manual switchover was accomplished with two switching operations at 8 a.m.

Highline Electric ended up shifting load to the western interconnect through four of its dual-grid substations and had several more substations that could have handled the additional load. Highline Electric stayed in this configuration for the rest of the day on Tuesday and shifted back into a more normal configuration on Wednesday.

“The process of shifting the load is fairly seamless to our customers, but it does result in a momentary ‘blink’ on our system,” Herman said. “We wanted to keep these brief interruptions to a minimum, and we did. Given the severity of the situation and the potential issues for our eastern cooperative members, however, we knew our customers would be more than willing to support the effort and deal with the minor inconvenience.”

For some consumer-members, that short blink in the lights represented a meaningful action by HEA to help ensure others could keep their lights on. Tri-State offered a “tip of the hat” to all those who experienced the momentary blink, yet another example of the cooperative spirit among our members.  

Highline Electric serves its customer load with 25 substations and more than 5,000 miles of distribution line.

“What we were able to accomplish cannot happen at many locations in the U.S., and certainly not among members that belong to the same generation and transmission cooperative,” Herman noted. “While it’s not something we want to do all of the time, we were able and honored to help out, because it shows the spirit of cooperation between cooperatives and their members. And, that’s just the way we do things in the Highline Electric service territory.”
 

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Tri-State is a not-for-profit cooperative of 45 members, including 42 member utility electric distribution cooperatives and public power districts in four states, that together deliver reliable, affordable, and responsible power to more than a million electricity consumers across nearly 200,000 square miles of the West.