Pleasant Prairie Community Development Department

Pleasant Prairie Power Plant Update

We Energies Commitment to Improving Air Quality

In September 2002, We Energies signed a voluntary Multi-Emission Cooperative Agreement with the Wisconsin Department of Natural Resources (WI DNR). In addition, they signed an Agreement with the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Justice that establishes a clear and comprehensive process to continually improve air quality and the Pleasant Prairie Power Plant's environmental performance. Over the next 10 years, with these agreements, WE Energies will invest $400 million to $600 million to further reduce air emissions from their power plants in southeastern Wisconsin. In March 2004, We Energies received approval from the Public Service Commission of Wisconsin to make environmental upgrades to the Pleasant Prairie Power Plant in The Village of Pleasant Prairie, the largest electric generating plant in the State. The following summarizes this project.

Questions & Answers

What is Pleasant Prairie Power Plant doing to improve air quality?

In April 2004, the Pleasant Prairie Power Plant began installing additional air quality control equipment to reduce emissions of sulfur dioxide by 90 to 95 percent and nitrogen oxides by 85 to 90 percent. The project will cost $325 million and will be completed in 2007.

Specifically, the project includes:

  • Installation of a selective catalytic reduction (SCR) system on Unit 1 to further control the power plant's emission of nitrogen oxides. The SCR is scheduled for operation in 2006. (A similar SCR system was installed in Unit 2 during 2002 and became operational in 2003.)
  • Installation of two wet flue-gas de-sulfurization systems (scrubbers) on both Unit 1 and 2 to further control the power plant's sulfur dioxide emissions. The Unit 1 scrubber is scheduled for operation in Nov. 2006, while the Unit 2 scrubber will be operational in April 2007.
How do these systems work?

The SCR system uses a dilute liquid (aqueous) ammonia solution and a catalyst to chemically convert the nitrogen oxides in the combustion gases into nitrogen and water.

This system is similar to catalytic converters in automobiles. The scrubber systems use a finely pulverized wet limestone and water solution to capture and remove sulfur dioxide from the combustion gases. We Energies beneficially uses the resulting product in their coal combustion products.

Why is We Energies doing this?

For more than a decade, We Energies has worked closely with both the WI DNR and the EPA to develop an integrated air quality strategy to further reduce air emissions from their power plants. In addition to their Agreements with these agencies, both the WI DNR and the EPA have proposed new regulations that will require reduced air emissions from all large power plants in Wisconsin. The construction and operation of the Pleasant Prairie Power Plant air quality control system will help We Energies meet both of these Agreements and future regulations.

How will the exterior of the plant change?

Pleasant Prairie Power Plant will look significantly different when the air quality control system is complete. The existing chimney stack will be replaced with a newer structure located approximately 300 feet farther east. (Removal of the existing chimney stack is scheduled for 2008.) The two scrubbers will be constructed near the base of the new chimney. Some existing warehouses will be removed to make room for these improvements and will be replaced with new structures elsewhere on the plant site. A white plume also will appear from the new chimney as water vapor will be created by the two new scrubbers.

When will this work occur and how will it affect neighbors?

Construction began in April 2004, including some site preparation activities followed by construction of the new chimney stack during the summer of 2004. The entire construction project consists of several phases and is expected to continue for approximately five years. The project will be complete by year-end 2007.

For more information regarding the Power Plant:
We Energies
231 West Michigan Street
Milwaukee, WI 53203

Pleasant Prairie Power Plant
8000 95th Street
Pleasant Prairie, WI 53158

Local Government Affairs
10411 Corporate Drive, Suite 100
Pleasant Prairie, WI 53158