(Bloomberg) -- The rapid development of data centers connected to the largest US electric grid raised costs by $9.4 billion, an expense that consumers from Illinois to Washington, D.C., will see reflected in their utility bills starting this month. Most Read from BloombergThe Global Struggle to Build Safer CarsICE Moves to DNA-Test Families Targeted for Deportation with New ContractAt London’s New Design Museum, Visitors Get Hands-On AccessLA City Council Passes Budget That Trims Police, Fire Sp