The utility company recently filed the petitions with the Indiana Utility Regulatory Commission.
2,000 homes and businesses in Indianapolis are still without power, and as many as 31,000 people were without electricity over the weekend.
The process will help IPL comply with EPA standards limiting coal-fired power plant emissions.
More than 12,000 people still don't have power after a wave of severe thunderstorms hit the state earlier this week.
Gov. Pence comments on news of a cancelled PR contract; Indy Power & Light breaks ground on an energy-storage facility. Read more in our morning roundup.
Indiana Power And Light Company says its dependence on coal will fall to 44 percent by 2017 as it switches to natural gas.
The Hoosier Environmental Council and other organizations say the byproduct of coal burning is a serious threat to the public's health.
More than 15,000 Hoosiers are without power after heavy snowfall and subzero temperatures hit the state.
The Environmental Protection Agency says the standards will help combat climate change, but Governor Mike Pence says the proposal could hurt Indiana's economy.
Once completed the natural gas plant would employ about two dozen people, approximately the same number as the coal plant.