Coal companies and electric utilities, long allied, are beginning to split. More than 100 of the 500 or so coal-burning power plants in the United States are expected to be shut down in the next few years. While coal still provides about a third of the nation's power, just four years ago it was providing nearly half.
The decline is largely because new pollution rules have made coal plants more costly, while a surge in production of natural gas through the process of hydraulic fracturing, known as fracking, has sent gas prices plummeting. Together, the economics of coal have been transformed after a century of dominance in Washington, state capitals and the board rooms of electric utilities.
"The math screams at you to do gas," said Mr. Morris, the chairman of American Electric Power, whose company is the nation's largest consumer of coal.