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Allen S. King Generating Station

Allen S. King Generating Station

This is a single-unit coal-fired generating plant


Location: Oak Park Heights, Minn., on the St. Croix River.

Plant Description: Allen S. King is a single-unit coal-fired generating plant with a cyclone boiler. The unit provides base load electric service, operating 24 hours a day, seven days a week.

Power Production Capability: 588 megawatts (MW) from one unit.

Fuel Sources: Low-sulfur Wyoming coal.

Plant History

The original King unit went into service in 1968 and served reliably for more than 35 years.

The King plant was completely rehabilitated from 2004-2007 as part of Xcel Energy's Metro Emissions Reduction Project. Improvements included steam turbine replacement, steam generator repairs and modifications, coal handling upgrades and the addition of state-of-the-art air quality control equipment. The improvements were targeted at significantly reducing air emissions and restoring the King unit to its original electricity output capacity, while extending the life of the plant.

The A. S. King plant was named in honor of Allen S. King (1900-1979), former president and chairman of Northern States Power Company (NSP), a predecessor to Xcel Energy. Allen S. King served almost half a century at NSP, and was an integral force in efforts to build cooperation among the nation's power suppliers to support electric service reliability.

Interesting Features

The plant's cyclone boiler burns up to 300 tons of coal per hour-about 2 1/2 railroad carloads- and generates 4 million tons of steam flow. A mile long, 600 ton-per-hour-capacity conveyor system several stories high, moves fuel from the coal yard to hoppers in the main building.

In addition to generating electricity, A. S. King supplies process steam to neighboring Andersen Windows, a large window manufacturer, for winter heating. Located on the border of Minnesota and Wisconsin, King also provides stability to the Upper Midwest transmission grid.

The A. S. King plant stack reaches 785 feet, taller than many of the office towers in downtown Minneapolis, 30 miles away.

Environmental Highlights

King has a long history of reducing emissions as technology has improved. The new air quality control system installed through the Metro Emissions Reduction Project includes flue gas scrubbers for control of sulfur dioxide emissions, selective catalytic reduction for nitrogen oxide control and fabric filters for control of particulate matter. The equipment will significantly reduce air emissions from previous levels.

King plant also was the model for a successful and growing peregrine falcon restoration effort, as the first plant in the nation to place a falcon nest box on it stacks. Several other Xcel Energy plants have joined the effort, along with other generating facilities worldwide. The plant also maintains an osprey nest box, and the land around the plant is home to other waterfowl and wildlife.

Community Involvement

A.S. King employees deliver Meals on Wheels in the St. Croix Valley area. Employees also are involved in United Way, Adopt a Family, Habitat for Humanity and Resident Business Leader volunteers for the Minnesota Business Venture summer camp program. The plant also has been involved in the development of bike trails and natural areas on company-owned property near the plant.

For more information contact:

Plant Information and Tour Requests — 1-800-895-4999
Minnesota Media Inquiries— 612-215-5300
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Why do our products and services differ based on state? Because our business is regulated by state. We have regulated operations in eight Western and Midwestern states. The different regulatory body for each state we serve determines what products and services we deliver in that state.