Taconite Ridge Wind Energy Center

Taconite Ridge Wind Energy Center

Visible for miles around and towering above the colorful ridges of U.S. Steel’s Minntac plant in Mountain Iron are 10 enormous wind turbines harnessing power from the wind and converting it to electricity. The Taconite Ridge Wind Energy Center has been operational since June.

APi Electric is proud to be part of the largest wind turbine installation in northeastern Minnesota, said Todd Lyden, senior project manager for APi Electric.

Each turbine is massive: 265 feet tall. The diameter of the spinning blades, 315 feet, is greater than the length of a football field. When the rotor is spinning at 15 to 18 rpm, the tips of the blades are moving at more than 200 miles per hour.

In ideal wind conditions, each turbine can produce 2.5 megawatts of power. That means the 10 turbines can collectively capture the wind and convert it into 25 megawatts of electricity — enough to power 8,000 homes on an annual basis.

It still gives me chills, said Andy Remus, Minnesota Power’s project manager for Taconite Ridge. It’s an awesome sight.

Collectively, more than 170 semi trucks were brought to the site as each turbine required 17 semi trucks to transport the turbine components.

APi Electric performed the complete electrical installation for the wind turbines. The electrical portion consisted of the installation of five major components: the electrical cable and bus connections in each tower; the transformer and vault at the base of each turbine; high voltage conductors in five miles of trenches between the towers and substation; control and fiber optic cables to the Taconite Ridge Operations Center and a complete grounding system.

The extensive grounding system consists of a ground grid at the base of each turbine that is eventually tied into a lightning rod that runs to the tip of each blade.

The electrical specifications include 84,000 feet of underground cable and enough power cable in each tower to allow the hub to rotate a full 360 degrees three times before it has to be rotated in the opposite direction.

Each rotor turns four generators mounted in the hub, producing 690 volts of DC (direct current) power which is then converted to 1400 volts of AC (alternating current) power before it leaves the tower en route to the pad-mounted transformer at the base of each tower. The voltage is then boosted to 35,000 volts for underground transmission to the Taconite Ridge substation where it is finally stepped up to 115,000 volts for transmission throughout the coverage area for Minnesota Power.

The turbines can be controlled from the on-site Taconite Ridge Operations Center or remotely at various locations.

A state mandate, passed in 2007, requires that Minnesota utility companies get 25 percent of their energy from renewable sources by the year 2025. The Taconite Ridge project will help Minnesota Power stay ahead of the curve.

The ability of APi Electric to perform every facet of the electrical installation on this project and the fact that APi Electric has completed numerous solar projects and two wind turbine projects uniquely positions us to assist other utilities in meeting their state’s renewable energy source mandates, Lyden said.

This green project uses no fossil fuels, therefore producing no carbon byproducts, he said. Only a wind of 5 mph is required to produce power. The Taconite Ridge Operations Center is pursuing a silver LEED certification.

[The wind turbines] give us more resources, Remus said. This is a part of maintaining and protecting the environment yet still expanding our business to meet our customers’ needs.

The $50 million project began in October 2007 and was completed in July 2008. Minnesota Power is an Alliance Partner with APi Electric.