RAPID CITY, S.D. (KOTA) – Utility companies continue the work to restore power to people following an outage that affected about 100,000 customers in western South Dakota, Wyoming, and Montana, according to the poweroutage.us website.

As of Thursday night officials stated that the system-wide power outage, which occurred close to 1:00 p.m. on Thursday, was caused by an event still under investigation outside the Black Hills Energy system, involving a third-party provider pulling power from a regional grid.

At a news conference Thursday evening, Black Hills Energy stated that it has been working with partner power companies around the region, but has no information on what happened further upstream.

Investigating the Cause

An explanation comes from an event involving two tripped 500-kilovolt power lines near Medicine Bow, Wyoming, as reported by Wyoming Public Media based at the University of Wyoming. In the article, Western Area Power Association (WAPA) public affairs specialist Stephen Collier had the following statement:

“We are aware of power outages affecting portions of Wyoming, including the central area of the state in and around Casper, as well as western South Dakota. We believe the outage, which began around 12:45 p.m. MST, was triggered by two tripped 500-kilovolt lines near Medicine Bow, Wyoming. This incident resulted in an abnormal voltage event that subsequently tripped a number of surrounding lines, including WAPA transmission, resulting in further power outages to communities across the area. We are coordinating with a number of major utilities in the area as well as other WAPA customers to address the outage as quickly as possible,”

• Stephen Collier, Public Affairs Specialist, Western Area Power Adminsitration

WAPA is run under the U.S. Department of Energy that markets power to a 15-state area, including the upper Great Plains in which KOTA Territory resides.

Gauging the situation

Black Hills Energy is also aware of other utilities that sustained damage, as reported by burnt power lines and explosions of utility boxes.

Regarding the scope and scale of this event, Wes Ashton, Vice President of Black Hills Energy’s South Dakota and Wyoming Utilities, states that one event comes to mind.

“The last time I can recall an event that had a system-wide impact was Winter Storm Atlas. So that’s been a number of years ago, more than a decade ago, in which a large winter storm knocked out or disrupted power for all of our Black Hills Energy customers in the area,” Ashton said.

“Since that time, we have made systematic investments and capital investments each year for the resiliency of our system, and so that’s something that we continue to invest in to make sure that we’re doing everything possible to keep the lights on.”

Prioritizing critical places

Ashton says that they prioritize places such as hospitals and customers with health issues. For safety… They ask people never to run generators indoors… Be careful with candles… Instead of using flashlights with batteries.

Regarding rumors that this was related to the recent solar storm/aurora… Ashton confirms that there is no connection.

To track and report outages and find out when power will be restored, check the following webpages:

blackhillsenergy.com/outages

www.precorp.coop/outage-map

www.montana-dakota.com/safety-education/outage-and-storm-information/