Alliant Energy: Launches second major environmental investment at Columbia Energy Center

Media Contact: Scott Reigstad (608) 458-3145

Investor Relations Contact: Sue Gille (608) 458-3956

Cleaner air and more jobs will result from state of the art power plant project

Alliant Energy and its partners launch second major environmental investment at Columbia plant

MADISON, Wis. – July 2, 2014 – Additional air quality improvements are planned for one of Wisconsin’s largest power plants. Today Alliant Energy’s Wisconsin utility, Madison Gas & Electric Co. and Wisconsin Public Service Corp. jointly filed a request with the Public Service Commission of Wisconsin (PSCW) to install air quality improvement technology at Columbia Energy Center near Portage, Wis.

“This project will improve the environment, create jobs and support Wisconsin businesses,” said John Larsen, President of Alliant Energy’s Wisconsin utility. “This air quality control system will help us provide customers with cleaner, reliable and efficient electricity for decades to come.”

The equipment responsible for cleaning the air is a selective catalytic reduction system (SCR) at Columbia Unit 2 that will reduce nitrogen oxide (NOx) emissions by approximately 50 percent. The estimated project cost is $150 million.

The SCR project is expected to begin construction in 2016 with an anticipated completion in 2018. The project will provide hundreds of jobs during peak construction.

Alliant Energy and its co-owner utility partners are completing their first major environmental investment at the plant. This year, baghouse and scrubber systems will be put into operation at Columbia Units 1 and 2, which will reduce sulfur dioxide (SO2) and mercury emissions by approximately 90 percent on each unit.

These projects are part of Alliant Energy’s plan to invest in air quality control systems at its newer, larger and most efficient generating units.

Alliant Energy Corporation’s Wisconsin utility subsidiary, Wisconsin Power and Light Company, utilizes the trade name of Alliant Energy. The Wisconsin utility is based in Madison, Wis., and provides electric service to 460,000 customers and natural gas service to 182,000 customers in more than 600 communities across central and southern Wisconsin. The employees of Alliant Energy focus on delivering the energy and exceptional service their customers and communities expect – safely, reliably, and responsibly. Visit alliantenergy.comor call 1-800-ALLIANT (800-255-4268) for more information. Alliant Energy Corporation is traded on the New York Stock Exchange under the symbol LNT.

This press release includes forward-looking statements. These forward-looking statements can be identified as such because the statements include words such as “approximately,” “expects,” or other words of similar import. Similarly, statements that describe future plans or strategies are also forward-looking statements. Such statements are subject to certain risks and uncertainties that could cause actual results to differ materially from those currently anticipated. Actual results could be affected by such factors as: state regulatory actions or local government actions which delay, prevent or alter the proposed plans, including inability to obtain all necessary approvals and permits; unanticipated construction issues, delays or expenditures, including accuracy of estimates of costs of labor, materials and equipment; failure of equipment and technology to perform as expected; current or future litigation, regulatory investigations, proceedings or inquiries that could impede the implementation of Wisconsin Power and Light Company’s (WPL’s) plans; political conditions in WPL’s service territories; changes to WPL’s access to capital markets; and economic conditions in WPL’s service territory. These factors should be considered when evaluating the forward-looking statements and undue reliance should not be placed on such statements. The forward-looking statements included herein are made as of the date hereof and Alliant Energy and WPL undertake no obligation to update publicly such statements to reflect subsequent events or circumstances.