Fossil-fuel advocates often lament that government subsidies for renewable fuels put more traditional power sources at a competitive disadvantage.

But subsidies take many forms. Now, as the biggest subsidy of all is about to expire, coal-fired power generation plants have admitted that they can’t compete in the modern market without it.

For well more than a century, coal-fueled power generators have been allowed to pollute with near impunity. The failure to make them pay for massive amounts of air and water pollution is a subsidy so large that it can’t be calculated.

The subsidy has not gone directly to those generators, but taxpayers have been left to pay for untold billions of dollars in environmental remediation costs that should have been the responsibility of the polluters.

Now a new federal rule requires coal-fueled plants to remove toxic heavy metals from their wastewater before dumping it into streams. According to the Environmental Protection Agency, that will prevent the annual release of about 386 million pounds of arsenic, mercury, selenium and other deadly poisons into the nation’s waterways.

Generators had until the end of October to notify state environmental agencies of how they planned to comply with the rule, which affects 75 big power plants nationwide. Of those, 21 plants — including Pennsylvania’s two largest, both near Pittsburgh — said they will close by the end of 2028, and five others said they would switch to burning natural gas.

The other plants that will close are in Georgia, Indiana, Louisiana, Maryland, Michigan, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee, Texas and West Virginia.

The closings are particularly good news for Pennsylvania. Not only will the shutdowns produce cleaner water locally, they vastly will reduce the amount of airborne pollutants that the wind carries from the South and Midwest to the Northeast.

Energy markets clearly are in transition. Even now, before the pending closures of the two big coal plants near Pittsburgh, the amount of electricity in Pennsylvania generated with coal has declined to just 10% of the total from more than 30% a decade ago, according to the U.S. Energy Information Administration.

That transition includes a shift in public subsidies from ignoring pollution to reducing it.

— Scranton Times-Tribune (AP)