SHARED SAVINGS PROGRAM SAVES ENOUGH ENERGY TO POWER 6,000 HOMES IN 2006

Madison, WI – Jan. 9, 2007 –Wisconsin Power and Light Company (WP&L), a subsidiary of


Alliant Energy Corporation (NYSE: LNT) today announced official 2006 energy savings


achieved by its Shared Savings energy efficiency program.


In 2006, WP&L achieved electric energy savings of more than 11.6 MW and 66 million


kilowatt-hours, or enough energy to power more than 6,000 homes. More than 1.3 million


therms of natural gas savings, or enough to supply 1,600 homes for a year, were also


achieved by Shared Savings in 2006.


The energy savings are a direct result of 227 Shared Savings energy efficiency improvement


projects implemented by WP&L agricultural, large business and industrial customers with


financing through the Shared Savings program.


“Based upon continued high customer demand for Shared Savings to implement energysaving


improvements, we project similar levels of customer participation and savings


achievement for the 2007 program,” said Donna Braatz, director – Sales and Strategic


Accounts.


2007 marks the 20th anniversary of WP&L’s Shared Savings program. In just the last nine


years, Shared Savings has resulted in the cumulative reduction of more than 998,000 tons of


carbon dioxide, the equivalent of taking 364,000 standard automobiles off the road.


More information on WP&L’s Shared Savings program can be found at


www.alliantenergy.com/sharedsavings.