The study concludes that cheap natural gas is the main reason for the decline of coal and nuclear power.

But according to Kim Smaczniak, a clean energy attorney with the environmental law firm Earthjustice, the final version of the report waters down key conclusions about the role of environmental regulations seen in an earlier draft.

And she says it adds recommendations to ease permits for coal power plants and safety requirements for nuclear power, and change how customers pay for power from older, less-efficient plants.

“Those are the findings that we see in the study that really aren’t backed up, and they’re findings that we didn’t see in the original version,” she states.

The coal and nuclear energy industries say the report confirms that the power they generate is critical to maintaining a reliable and resilient electric grid.