Alliant Energy Utilities Alliant Energy Visit Website 4902 N Biltmore Lane Madison, WI 53718 (800) 255-4268 About Map About Alliant Energy provides energy solutions to more than 1.4 million customers in Iowa, Minnesota and Wisconsin. The corporate headquarters is in Madison, Wisconsin. They currently have nearly 4,200 employees working across their service territory. What's Nearby? Distance: 5 10 15 20 25 50 mi.