JUDY WOODRUFF:

The future of coal is very much at the center of debate right now when it comes to the politics and business of energy.

Whatever you may think about those questions, the U.S. still uses a lot of coal. About 30 percent of our energy, of our electricity is generated by it.

For some, the Holy Grail is new technology that captures some of coal's worst problems with greenhouse gases.

Miles O'Brien reports on the largest facility trying to do so.

It's part of our weekly series on the Leading Edge of science and technology.