The Indiana NAACP says keeping coal plants open longer would negatively affect the health of low-income and minority communities in the state.

An administrative law judge ruled Indianas environmental agency broke its own public comment rules when it issued an air pollution permit for a planned $2.5 billion coal-to-diesel plant in Spencer County.

A bill that would make it harder for utilities to close coal plants in Indiana passed in the state House on Monday 52 to 41.

The bill's author says utilities are relying more and more on renewable energy sources and the energy marketplace -- and that could threaten reliability.

Bloomington-based Hoosier Energy said it will idle the coal-fired Merom Generating Station in Sullivan County as part of a transition to other energy sources including wind, solar, natural gas and storage.

Indianapolis Power & Light plans to close two of its four coal units at its Petersburg plant by 2023. But environmentalists say IPL needs to move away from coal more quickly.

Gibson County Coal filed a notice Friday. The layoffs are effective Jan. 15.

The Energy Policy Development Task Force met Thursday, for the final time this year, and debated ways to balance the use of coal and renewable energy sources.

Experts say half of Indiana's coal plants are 40 years old or more and will need expensive repairs in the next 30 years.

The Petersburg Generating Station activists want to see closed is a coal-fired power plant in southwest Indiana. It's been in the news as what's called a "super polluter."