Utilities mark power plant upgrade in Ottumwa

A $491 million comprehensive air quality control project and efficiency upgrade at the Ottumwa Generating Station will reduce emissions and produce more energy while using less fuel.

The plant, jointly owned by Alliant Energy's Iowa utility and MidAmerican Energy, burns coal to generate 726 megawatts of electricity. The utilities on Monday marked completion of the upgrade, which began in the second quarter of 2012.

The technology is designed to reduce emissions of sulfur dioxide and mercury by 90 percent. It also will meet pending Environmental Protection Agency emissions regulations.

John Larsen, senior vice president of generation for Alliant Energy, said new equipment is expected to enable the power plant to produce more energy while using less fuel. Since 2005, Alliant Energy has reduced emissions at a number of generating stations, reducing its overall carbon dioxide output by about 15 percent. The company expects to change fuels or retire more than 1,400 megawatts of the company's fossil-fueled generation by 2020.

While the changes at the Ottumwa Generating Station primarily will have an environmental impact, the projects also created an economic development impact.

At the peak of construction, more than 800 skilled-labor workers logged more than 1.9 million hours to complete the work. The construction required the pouring of more than 7,800 cubic yards of concrete and the use of 7,900 tons of steel.

Alliant Energy's Iowa and Minnesota utility, Interstate Power and Light, provides electric service to 528,000 customers and natural gas service to 234,000 customers.