The Affordable Clean Energy rule is the Trump administration's replacement for the Obama-era Clean Power Plan.

The Indiana Office of Utility Consumer Counselor says Vectren needs to explore all its options before it builds a new $780 million natural gas plant.

IPL forecasts that the plant's capacity factor - or how often it can run - will increase to 70 percent next year. That's up from less than 60 percent in 2015.

A planned $2.5 billion diesel fuel facility would be located on a 550-acre site annexed by the town of Dale last year.

Coal production is up almost 2 percent from the same time last year and about 15 percent from 2016.

While rates have been on the rise, the Hoosier state is burning less coal for electricity. Coal accounted for 65 percent of the fuel used for electricity in 2016, down from 85 percent in 2007.

The study finds cheap natural gas and declining power demand are driving coal and nuclear power plant closures.

While coal advocates praise the move, it introduces "uncertainty" for the state's electric utilities.

Trump's executive order reverses an array of Obama-era climate policies.

Activists were concerned with the brevity of Gov. Holcomb's comments on energy and environment issues.