Ask Mr. Science Cartoonist: Clean Coal

First of what I hope will be an unnecessary series explaining how things work.

We've been hearing a lot about "Clean Coal" lately, most recently in the president's State of the Union address lauding America's "beautiful Clean Coal." I realized that neither he, nor most people with very strong opinions about it, had any idea what it means. What the world needs is more learnin' from cartoonists, especially one who also spent 20 years working as a science writer for the energy industry.

That's me.

Clean Coal is not a type of extra-special coal. It's a way to burn coal more cleanly.

Coal is a hydrocarbon. So are oil, gasoline, natural gas, propane and methane.

They're called "hydrocarbons" because they're made of hydrogen (H) and carbon (C).

When you add oxygen (O) and burn them in a car engine or power plant, you release energy and recombine all the H's, C's and O's in new ways. For example, you make H2O (water), which is why you see water dripping from a car's tailpipe. You make carbon monoxide (CO), which is why you don't leave your car running in a closed garage. And you make carbon dioxide (CO2), which is a greenhouse gas that traps infrared radiation and helps drive global warming.

It doesn't matter if you believe global warming is real. It's happening whether or not you believe in it.

So burning coal blows carbon out your power plant's smokestack into the air. Clean Coal is a general term for catching it before it gets away. The Department of Energy (DOE) has spent decades researching different techniques and technologies to do it. In recent years, they reached one solid conclusion:

All Clean Coal methods raise the cost of generating electricity and hurt the energy efficiency of their power plants. While some of them look good technologically, none of them make the least sense economically. Depending on where you are in the country, other energy sources--even solar--are already cheaper than regular coal power. Adding the cost of capturing coal's carbon exhaust makes it one of the most expensive fuel sources around. Given that, DOE cut research on Clean Coal a few years ago.

Clean Coal has nothing to do with political philosophies, the specialness of American coal, or the hopes and dreams of our noble coal miners. It's an approach to burning coal cleanly that for now--with our current economy and technology--just doesn't work.

I'll bet it took less than two minutes to read this post, and now you know more about Clean Coal than the president of the United States and most of Congress. Take the rest of the day off.