Windstorm underscores need for energy diversification
- Jan 21, 2021 8:32 am GMTJan 21, 2021 2:52 pm GMT
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The automatic shutdown of turbines during Montana's windstorm last week prove the need to maintain multiple energy sources to prevent consumers from experiencing "higher costs, lower reliability and grid instability," NorthWestern Energy officials say.
John Hines, the company's vice president of supply, said the Jan. 13 storm forced the automatic shutdown of many wind turbines in Montana. Those that generated close to their maximum capability of 430 megawatts on Tuesday afternoon, Jan. 12, completely shut down the next morning when wind speeds accelerated to around 70 miles per hour.
On Jan. 13, electricity generation fluctuated every 15 minutes from about 280 megawatts to less than 30 megawatts as the wind howled across the state, illustrating that "there is always the potential to be 450 megawatts long or 450 megawatts short when it comes to meeting our customers' demand with the wind resources in our Montana portfolio," Hines said.
Although it varies by turbine, the cut-out speed designed to prevent damage to equipment is generally 55 miles per hour, according to the U.S. Department of Energy. Last week's storm generated gusts ranging between 65 miles per hour to more than 90 miles per hour across the state.
According to a NorthWestern Energy news release, 67 percent of the company's energy portfolio comprises carbon-free sources, including wind, which it describes as a "good, clean energy resource, available 24/7." However, because it is a variable resource, it creates unique challenges to operating the energy grid reliably. Because of those challenges and built-in variability, the company does not rely on wind during times of critical energy demand, such as cold winter night and hot summer days.
The service outages experienced by some customers last week underscore the need for flexible capacity resources available on demand, such as hydro, storage and natural gas to keep the grid balanced and operating reliably at all times, the company asserts.
"NorthWestern Energy's redundant grid and energy generation resources located in Montana were critical to limiting customer outages," said Vice President of Transmission Mike Cashell. "This storm underscores the value flexible resources within NorthWestern Energy's service area contribute to maintaining reliability when conditions are good and when the weather turns and creates challenges."