[5][6] In 2009, faced with environmental regulations regarding future operations, the owners of Columbia Energy Center invested in upgrades to the plant.

The owners submitted an Electric Generation Expansion Analysis System (EGEAS) summary report to the Public Service Commission of Wisconsin on April 2, 2009.

Columbia's owners were granted a Certificate authorizing the installation of air emissions reductions systems and associated equipment on March 11, 2011, at an estimate cost of $627 million.

[13] After receiving a $30 million federal grant, Alliant Energy announced it would build a 20MW / 200MWh storage system on the site, similar to a prototype in Italy.

The storage system is a novel closed-system carbon dioxide technology that converts the gas to liquid and back again at 75% efficiency, depending on demand.