A glaring example of how legislation often serves narrow special interests rather than effective public policy is an old state law requiring many state-owned institutions, including prisons, to burn coal.

For a century coal not only was the predominant fuel but the predominant industry in Pennsylvania. Even as the industry declined across the middle of the 20th century, it had sufficient influence to keep the state government as a major customer through legislation rather than through the marketplace.

Now, several state prisons, including the State Correctional Institution at Waymart in Wayne County, want to free taxpayers from the grasp of uneconomical coal.

The prison, which houses about 1,500 inmates and employs 660 staffers, burns between 7,000 and 8,000 tons of coal each year. During the recent cold snaps, it has burned up to 35 tons a day. And its coal use is constant because it also uses the fuel for hot water generation. SCI Waymart's coal bill is more than $1 million a year.

Gas is the new predominant fuel and industry in Pennsylvania and it is eating coal's lunch not through legislation but in the marketplace.

The coal industry has complained that domestic use has fallen because of federal environmental regulations. Implementation of those rules has indeed caused large-volume coal users to consider other fuels. But there is nothing wrong with finally placing a price on the pollution that coal has generated - at no cost to producers or utilities - across generations. And newly abundant gas has proved to be not just cleaner, but cheaper than coal. That's why power utilities have been abandoning coal for gas, and why the state should enable all of its institutions to explore options.

It doesn't have to be gas. It could be some combination of renewables, such as wind or solar power where geography accommodates them, along with gas or geothermal.

But the state mandate should be for efficiency and environmental stewardship rather than for a particular industry.