Willmar Municipal Utilities creates plan for power generation if transmission grid goes down
The Willmar Municipal Utilities Commission has approved a catastrophic event transmission plan to provide electricity to its customers in case of a complete failure of the transmission system. Willmar would produce electricity using diesel generators, some owned and some rented, and would use rolling blackouts to turn the lights on for a section of the city at a time.
WILLMAR — With the Willmar Power Plant shutting down at the end of June, Willmar Municipal Utilities is losing most of its ability to generate its own power.
"We will be losing approximately 24 kilowatts of local generation," said Jeron Smith, staff electrical engineer.
Normally that would not be a problem, since Willmar purchases pretty much all of its electricity on the open market, which is significantly cheaper than generating its own. The power reaches the city through the large transmission lines that crisscross the state and nation.
But what happens if those transmission lines go down, due to a massive mechanical failure or a natural disaster, and that purchased power can't reach Willmar? Over the past several months, staff at Willmar Municipal Utilities have been working on a catastrophic event plan, which would use diesel generators to produce power for the city in the event the transmission grid is down.
"To maintain reliability we have looked at the feasibility of using rental generation," Smith said.
The plan, which the Willmar Municipal Utilities Commission approved at the March 23 meeting, would call for the rental of seven 2-megawatt diesel generators from Ziegler CAT. It will cost approximately $150,000 to install the infrastructure needed to be able to plug the rental generators into Willmar's power distribution lines.
During the first 24 hours of a catastrophic event, Willmar Municipal Utilities crews would be checking and repairing the local power lines in Willmar to make sure they are safe to re-energize. Then the four diesel generators the city already owns could be turned on, providing power to some parts of the city.
"Just to note, the majority of the city would remain without power until that rental generation is delivered and installed," Smith said.
Once Willmar Municipal Utilities puts in the call to Ziegler to send the rental units, they should reach Willmar within 24 hours.
"Ziegler has 15 to 20 of these units in our region," Smith said. "They can come from several directions if there are some road closures."
The seven rental and four owned generators would be able to produce approximately 26 megawatts of electricity, enough to provide power to at least a quarter of the city at a time.
"We would do four rolling blackouts," Smith said.
The available generation should be able to meet the power needs of each sector, though Willmar Municipal Utilities would ask its customers to conserve power during a catastrophic event.
Many of Willmar's essential services, including its water plants and the hospital, have their own backup generation that would kick in if there is a blackout in Willmar.