AES Indiana was formed as the Indianapolis Power and Light Company in October 1926 by the merger of the Indianapolis Light and Heat Company and the Merchant's Heat and Light Company. Those two companies had started providing electrical service in the 1880s. At the time of the merger, the company had 105,000 customers. In 1937, IPL began a
rural electrification program, running power lines to many areas outside
Marion County. The company moved into its present-day headquarters building on
Monument Circle in
downtown Indianapolis in 1935; the building, now known as the Electric Building, had been constructed in 1924 for the Continental Bank. IPL was acquired by the
AES Corporation in 2001. On February 24, 2021, IPL's name was changed to AES Indiana. At that time the company had 500,000 customers. On April 25, 2021, the company's Eagle Valley Generating Station's Toshiba steam turbine was unable to resynchronize with the grid when it was restarted after a maintenance outage. The problem was caused by a disconnected wire that "provided false indication to the control system". Repairs to the resulting damage to the rotor and other components was hampered by incorrect wiring diagrams in the system manuals and could not be completed until November 2021. The company's Petersburg Generating Station also was undergoing repairs during part of the time, causing AES to purchase $1 million of electricity to cover the shortage. In March 2026, a consortium led by
BlackRock subsidiary
Global Infrastructure Partners and Swedish private equity firm
EQT AB agreed to acquire AES Indiana's parent company AES for a total enterprise value of $33.7billion, including its $22.7bn of debt. AES Indiana, along with AES Ohio, will continue as locally operated and managed regulated utilities. ==Generating plants==