Increasing electric transmission capacity while providing cost benefits

Republic Transmission is installing a new high-voltage transmission line between the existing Duff substation in southern Indiana and the existing Coleman EHV substation in northern Kentucky.

Southern Indiana and Northern Kentucky were identified by the 2015 MISO Transmission Expansion Plan (MTEP) as having significant transmission congestion impacting nearby large industrial loads and projected load growth in the region.  MISO determined that a new extra-high voltage transmission line would increase reliability by strengthening the regions’ transmission backbone and reduce congestion, allowing lower cost generation resources to reach load. The result will be safe and reliable delivery of power while providing lower system costs for the entire MISO electric transmission grid.

About the project

The Duff to Coleman Project is a new single circuit 345 kV transmission line, which will cover approximately 30 to 35 miles through Dubois County, Indiana; Spencer County, Indiana; and Hancock County, Kentucky. MISO’s MTEP analysis estimated that the project would provide over $1 billion in benefits which far exceeded the cost for the project.


A strong, experienced and trusted team

To execute the Duff to Coleman Project, Republic Transmission has collaborated with three experienced utility companies: LS Power, Hoosier Energy and Big Rivers Electric Corporation. With the managerial, technical and financial capabilities of our majority parent company, LS Power, and the local knowledge and experience of Hoosier and Big Rivers behind us, Republic Transmission is equipped to develop, construct, own, operate, and manage this project and future transmission projects.

Republic Transmission understands the importance of working closely and proactively with landowners and stakeholders. One of our top priorities is to remain transparent by keeping all involved parties informed of the details of the project while it is being installed as well as answering questions and responding to issues. Once the project is completed, we are equally committed to maintaining this transmission line in a safe, efficient and environmentally conscious manner.

Lending managerial, technical and financial strength, and personnel

This privately held power generation and transmission company, owns and manages one of the largest and most diverse independent power generation and transmission portfolios in the U.S., and is an indirect majority owner of Republic Transmission. The company has managed the development of over 9,000 MW of greenfield generation, including multiple natural gas-fired generation, two coal-fired generation and three utility-scale solar facilities. Through its subsidiaries and affiliates, LS Power has developed, constructed, managed or acquired more than 30,000 MW of competitive power generation and over 500 miles of transmission infrastructure across the country.

Role in the project: LS Power lends its technical, financial and management skills, and extensive experience to the Duff to Coleman Project. The generation and transmission company also equips Republic Transmission with the management personnel needed to develop, construct, own, operate and manage this project. Throughout its history, LS Power has always worked closely with stakeholders and is committed to doing so on this project.

Providing technical and maintenance support in Indiana

This generation and transmission cooperative, which provides wholesale electric power and services to 18 member distribution cooperatives in central and southern Indiana and southeastern Illinois, is an indirect minority owner of Republic Transmission. Hoosier Energy owns approximately 1,700 miles of transmission lines, most of which are located in Indiana.

Role in the project: Hoosier Energy currently operates and maintains transmission facilities in the same part of Indiana as the Duff to Coleman Project. Republic Transmission is leveraging the company’s technical capabilities in the construction and operation of the Duff to Coleman Project, benefitting from Hoosier Energy’s existing local operations and maintenance experience and capabilities. After the project is completed, Republic Transmission intends to utilize Hoosier Energy to handle ongoing operations and maintenance activities in Indiana.

Facilitating operations and maintenance in Kentucky

A member-owned, not-for-profit, generation and transmission cooperative, Big Rivers Electric Corporation delivers wholesale electric power and services to three distribution cooperative members across 22 counties in western Kentucky.

Role in the project: As the local transmission provider in Kentucky and the owner of the Coleman substation, Big Rivers is providing Republic Transmission with development assistance, local knowledge, and local operations and maintenance capabilities. Once the project is energized and functional control is turned over to MISO, Big Rivers plans to acquire the Kentucky section of the transmission line.

Need more information about the Duff to Coleman Project? Contact us.

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