All hands on deck: Co-ops step up during heat wave

In late July, a heat dome settled over the heart of the country, causing electricity demand to soar.

In response, the Midwest grid operator, MISO, declared conservative operations. This meant that utilities in the region had to keep all grid resources on standby, ready for action.

Great River Energy quickly rescheduled all planned maintenance and focused on prepping every generation and transmission resource to handle elevated electric demand.

“These are the types of weeks we prepare for,” said Great River Energy Power Supply and Markets Director Greg Padden. “We had sufficient power supply resources to meet our members’ needs, with a surplus of generation capacity available at peak times to support grid reliability and produce revenue for the membership.”

Saturated soils and strong winds can pose major challenges to transmission reliability, but Great River Energy’s system held strong through several rounds of storms, according to Great River Energy System Operations Director Mark Peterson.

“[That weeek’s] performance is a testament to the way our system is designed and maintained — we were ready.”

— Mark Peterson, Great River Energy system operations director

Great River Energy took the rare step of dispatching all member demand response resources on July 28. Great River Energy and member-owners reduced electric load by interrupting water heaters and cycling air conditioners on and off for member-consumers enrolled in demand response programs.

The cooperative called on irrigation members and commercial and industrial members equipped with backup generators, as well as those who voluntarily curtail electric service under Great River Energy’s programs.

“We were able to reduce demand by hundreds of megawatts during periods that saw day-ahead market prices reach over $300 per megawatt-hour,” said Great River Energy Member Services Director Jeff Haase. 

For comparison, the average wholesale price of electricity in Minnesota in July was approximately $60 per megawatt-hour.

Not only did Great River Energy avoid high-price purchases, but it was also able to sell energy into the market at opportune times. Every Great River Energy peaking power plant was called on to generate electricity over the heat wave.