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Montana-Dakota Utilities believes it is the first in North America to deploy aluminum-encapsulated carbon fiber conductor

BISMARCK, N.D. — March 15, 2021 — Montana-Dakota Utilities believes it is the first company in North America to use an aluminum-encapsulated carbon fiber core conductor in its transmission system. The utility saved a year on the project schedule and 40% of the cost by implementing the new technology. Montana-Dakota Utilities is a subsidiary of MDU Resources Group, Inc. (NYSE: MDU).

Because of its makeup, the aluminum-encapsulated carbon fiber core conductor:

  • Can carry significantly more amps of electricity than traditional conductor of the same size.
  • Is lighter weight, which means it can be installed using existing infrastructure.
  • Reduces line loss by 20%. Line loss refers to the energy lost during transmission and distribution across the grid.

The carbon fiber core is responsible for 97% of the mechanical strength of the conductor. The conductor is wrapped in two layers of softer aluminum, which has a higher conductivity than the aluminum used in traditional conductor.

steel core
Traditional conductor has a steel center and is encased in ribbed aluminum.
carbon fiber
The new conductor has a carbon fiber core and is wrapped in two layers of flat aluminum. The outer aluminum has been lifted to show the layers.









Traditional conductor has a steel core with an aluminum exterior. The steel core is responsible for 83-87% of the mechanical strength of the conductor; the remainder of the strength is from the other materials that encase the core.

Jon Wahlgren, senior engineer with Montana-Dakota Utilities, said the company was looking for ways to increase the load the 230-kilovolt transmission line from the Napoleon, North Dakota, wind farm to the Heskett substation in Mandan can carry. Demand is growing, largely due to wind farm development in the area.

The Napoleon-to-Heskett line is 60 miles long; Montana-Dakota installed the carbon fiber core conductor on 11 miles through Bismarck.

“If we would’ve used traditional conductor, it would have required replacing all the structures on the line to maintain adequate clearance, as well as support a larger, heavier conductor,” Wahlgren said.

The carbon fiber conductor’s reduced line loss offers environmental benefits. Traditionally, utilities push more energy through lines than is required to account for what will be lost during transmission. With reduced line loss through the carbon fiber conductor, the utility can push more capacity through the line and less energy is wasted.


About Montana-Dakota Utilities

Montana-Dakota Utilities Co. distributes natural gas and generates, transmits and distributes electricity and provides related services in the northern Great Plains. The company serves approximately 143,000 electric customers and 280,000 natural gas customers in 270 communities in North Dakota, South Dakota, Montana and Wyoming. For more information about Montana-Dakota, visit


About Rocky Mountain Contractors

Rocky Mountain Contractors, Inc. is part of MDU Construction Services Group, Inc. Rocky Mountain Contractors provides electric, gas and telecommunications construction services. The company is headquartered in Helena, Montana, and has operations across the state. For more information, visit


About MDU Resources

MDU Resources Group, Inc., a member of the S&P MidCap 400 index and the S&P High-Yield Dividend Aristocrats index, is Building a Strong America® by providing essential products and services through its regulated energy delivery and construction materials and services businesses. For more information about MDU Resources, see the company’s website at or contact the Investor Relations Department at [email protected].


Forward-Looking Statement

The information in this release includes certain forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking statements contained in this release, including statements made by company management, are expressed in good faith and are believed by the company to have a reasonable basis. Nonetheless, actual results may differ materially from the projected results expressed in the forward-looking statements. For a discussion of important factors that could cause actual results to differ materially from those expressed in the forward-looking statements, refer to Item 1A-Risk Factors in MDU Resources’ most recent Form 10-Q and 10-K.


Media Contacts:

Mark Hanson, Montana-Dakota Utilities communications, 701-530-1093

Andrea Blessum, MDU Construction Services Group communications, 701-530-1054


Financial Contact: Jason Vollmer, vice president, chief financial officer and treasurer, 701-530-1755


Call 701-530-1093 between 8 a.m. and 5 p.m. CT Monday through Friday.

Email: [email protected]