OK, chemistry nerds, this one's for you. Some bright bulbs over at Rutgers University and UNC Chapel Hill have discovered a way to make liquid fuel - diesel, in fact - out of solid lumps of good old-fashioned coal. What's that? You say it's been done before? Well, sure. Germany powered much of its World War II machinery with coal turned to diesel by a handy bit of chemical voodoo known as Fischer-Tropsch synthesis, in which sources like biomass, natural gas, or coal are heated to release carbon monoxide and hydrogen molecules, which are then reformed into, among other things, liquid diesel. (Pay attention; there will be a quiz.)

It's hard to believe the words “clean” and “coal” could ever be uttered in the same breath. But a high-tech concept for low-emission coal power is increasingly gaining acceptance among industry executives and environmentalists alike. Like it or not, coal already accounts for 50 percent of America's electricity production, and yes, much of that comes from dirty old smog- and CO2-belching plants. The good news is that next-gen technology is on the horizon that could eventually make coal power emissions-free.