Coal costs more to generate electricity

Can you replace coal-fired electric generation with solar power even though the sun isn't up 24 hours a day? Are coal mines closing because of economics, or is it just politics?

As mentioned in my first column, my father got a lifetime achievement award from the coal industry. I've been underground in coal mines. I grew up with positive dinner table talk about coal: The U.S. has hundreds of years of coal reserves. "Mine-mouth" generation was eliminating the need to ship coal before burning it. Under regulatory pressure, the industry was inventing and adopting systems that reduced sulfur, nitro...