NorthWestern Energy, SD
How often NorthWestern Energy goes out
NorthWestern Energy customers in South Dakota had 1.1 interruptions last year, 2 hours total - a bit below the typical US utility's outage time. That is 55% less outage time than the South Dakota state average of 4.5 hours a year.
What a typical outage at NorthWestern Energy looks like
Outages here typically run short, about 1.7 hours before power is back - a battery power station or small portable generator should cover the essentials through most of them. The frequency-versus-duration guide covers why length decides the kind of backup.
Do NorthWestern Energy customers need a generator
Serving 64,904 customers here, Outages at NorthWestern Energy run below the national norm, so a generator is not urgent - still worth checking if you have medical equipment or a sump pump that cannot go without power.
How NorthWestern Energy's record was measured
NorthWestern Energy filed these numbers itself, as an investor-owned utility, under EIA Form 861 - a federal reliability report covering its entire South Dakota territory, serving 64,904 customers here, not a single street or outage. See South Dakota as a whole, across every utility that filed: South Dakota's outage record. How the verdict bands are set is in the methodology.