Wind power has made incredible inroads into the U.S. energy system thanks to big, efficient machines standing hundreds of feet tall. But the future of wind power may be underground. In the abandoned mines and sandstones of the Midwest, compressed-air storage ventures are trying to convert the intermittent motions of the air into the kind of steady power that could displace coal. Compressed-air energy... 

Electric cars have been getting a lot of buzz lately, but a more immediately viable transportation fuel of the future could be liquid derived from coal. Scientists have devised a new way to transform coal into gas for your car using far less energy than the current process. The advance makes scaling up the environmentally unfriendly fuel more economical than greener alternatives. If oil prices rise...