Energy when it matters most

During cool weather in March and April, the operations and maintenance crews at Great River Energy peaking stations are hard at work with summer operations in mind.

“The maintenance we do in the springtime gets the plants ready for the hot weather in June, July and August — that’s what we prepare for,” said Great River Energy Combustion Turbine Leader Preston Walsh, whose team operates and maintains the cooperative’s northern Minnesota peaking stations.

Utilities like Great River Energy perform maintenance in the spring and fall to prepare for increased electricity use in the summer and winter.

The role of ‘peaking’

Peaking stations can produce precise amounts of energy when it’s needed. Great River Energy’s peaking stations are strategically located throughout Minnesota and possess the collective ability to produce more than 1,300 megawatts of electricity.

Great River Energy’s peaking stations can provide energy in any amount, from a small boost to the full output of the fleet. And, they can begin feeding energy to the electric grid within minutes.

As Great River Energy transitions its power supply portfolio away from coal and increasingly toward renewable energy, peaking stations will provide the core reliability that members expect and depend on.

For much of the year, electricity demand in the Midwest is met by a combination of large and medium-sized power plants and renewable resources. Peaking stations produce energy during the moments that those other resources aren’t sufficient, currently up to 5% of the year.

Each peaking unit undergoes annual testing to measure the amount of electricity it can provide and how quickly it can begin feeding the electric grid.

“There is a lot of work behind the scenes to balance the electric grid,” Walsh said. “Grid operators need to know exactly what they can expect when they deploy a peaking station.”

Peaking stations are particularly important during extreme weather, such as the heat waves Minnesota experienced in early June and July. In fact, Great River Energy’s peaking stations set a June energy production record this year. As extreme weather events are happening with more frequency and intensity, peaking generation satisfies the important role of reliability assets, providing on-demand energy to the grid.

A complement to renewables

As renewable energy has grown in the Midwest, peaking stations have begun to fulfill an additional purpose as a dependable backup to non-dispatchable resources such as wind and solar. What has previously been viewed as a bridge technology to a renewable future has quickly proven its value in concert with those resources.

“When the wind subsides or sunlight fades, the grid needs an energy source to come online quickly,” said Great River Energy Vice President and Chief Power Supply Officer Jon Brekke. “Peaking stations are a critical complement to renewables to ensure electricity is reliable in any weather.”

Great River Energy plans to add 900 megawatts of wind energy in the coming years, more than doubling the cooperative’s supply of clean energy.

“Within two years, renewables will represent a majority of the energy we use to serve our member-owners,” Brekke said. “We are able to achieve that only because we have our peaking stations there to ensure reliability at all times.”