Minnesota Power completes new transmission line

Minnesota Power, a division of Allete Inc., installed several related electric infrastructure projects including substations and new transmission lines near Nashwauk, Minn.

Minnesota Power, a division of Allete Inc., installed several related electric infrastructure projects including substations and new transmission lines near Nashwauk, Minn., that will energize the Essar Steel Minnesota taconite mine and processing facility.

Minnesota Power and its contractors worked for two years to construct and install the $35 million in transmission assets needed to satisfy the large power demands of Essar, which is constructing a mine, concentrator and taconite production facility.

Essar is an electric customer of the city of Nashwauk, which receives all its electricity through a municipal contract with Minnesota Power. When it reaches full production, the Essar facility will require about 110 MW of electricity.

Essar continues to evaluate options and develop plans for future growth including direct reduced iron, steelmaking and potentially other product lines, which could ultimately result in a doubling, or more, of electric power requirements as well as construction of an additional 230-kV transmission line.

Minnesota Power signed an agreement in February 2012 to meet all of Nashwauk's electric requirements through June 30, 2024. Nashwauk subsequently agreed to provide Essar with all the electric service needed for the company's proposed taconite facility and any additional future growth.

The project included construction of three new 230-kV transmission lines, one of which has a five-mile segment of double circuit 230 kV and 115 kV line. A 230-kV line was removed, and a 115-kV line was re-routed around the Essar property, tying a Great River Energy circuit to the Minnesota Power 115-kV system, and providing fiber communications to two new substations. In total, 28 miles of lines were built and 21 miles were re-routed or removed.

One of the new substations, the McCarthy Lake facility, was built to serve the taconite plant and the new Calumet substation will serve the mine area. Ownership of these facilities and the costs to build them will be split between Nashwauk and Minnesota Power. Substation construction began in August 2011 and was finished earlier this month.

It took about 45 contract workers to complete the clearing and construction needed for the new transmission lines. Work on the 230-kV project was completed March 8. Remaining work on the 115-kV line will be completed in about two weeks.

Minnesota Power provides retail electric service within a 26,000-square-mile area in northeastern Minnesota to 144,000 customers and wholesale electric service to 16 municipalities.

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