In the face of the juggernaut moving toward green power, one question looms unanswered: What will become of coal?

After all, coal is the single largest source of power for generating electricity in the United States. No other source comes close to matching its output, and even renewables, with all of their recent growth, represent only a small fraction of the U.S. total by comparison.

Despite the advantages it enjoys from such a huge footprint, the coal industry may be finally starting to show the effects of change. In its 2010 year-end report on the industry, the U.S. Energy Information Administration showed an annual decline of 3.6 percent in the number of coal mines in the United States and an 8.3 percent decline in the total output of coal.

Similarly, the Sierra Club recently cheered an apparent contraction in coal-fired plants. No fan of coal, the environmental advocacy group reports that, in 2010, the industry did not begin construction on any new plants, abandoned 38 proposals and retired 48 plants. The retired facilities represented about 12,000 megawatts (MW) of electricity.

According to the National Mining Association, half of U.S. electricity is generated from coal. It is still the most affordable source of power, averaging less than one-quarter the price of petroleum and natural gas, both of which are also much cheaper than solar, wind and other forms of renewable power.
That’s a huge advantage to overcome. By comparison, solar, wind and other renewables each represent 1 percent or less of the total electricity generated in the United States. In short, they have a long way to go to replace coal.

But the amount of pollution coal produces has been the black mark the industry can’t scrub off. When people talk about greenhouse gases, global warming and CO2 emissions, they are talking about coal. The Sierra Club applauds the 109 million tons of pollution that didn’t occur from the coal plants that were not built and those that were abandoned or retired in 2010.

A new technology called carbon capture and sequestration (CCS) allows coal-fired facilities to capture and bury harmful CO2 gases underground where they can’t contribute to global warming. It holds some promise for coal’s redemption in the form of so-called “clean coal” or “coal without carbon.”

However, the technology is unproven, and the momentum is clearly on the side of renewable power, which doesn’t produce anything that is buried underground.