Coal. Dirty, old world coal. Surely, after a couple hundred years of use, there's nothing particularly interesting about such an anti-environmental dirty, destructive (strip mining and acid rain, particulates and mercury) commodity. Solar and ethanol are the way to go, right?
Well, yeah, except for one little niggling bit about them both being completely uncompetitive with coal based on price alone. So there are lots of market manipulations (taxes, 'total environmental impact accounting', etc.) to try and make the 'green' energy sources look price competitive with the 'dirty' sources. But at the same time, there has been 30 years of work (since the 1971 Clean Air Act) to make those 'dirty' sources clean, and those efforts have been enormously successful.
Today, the drivers toward 'clean' energy are not really pollution derived, since almost any energy source can be used today in a relatively pollution-free fashion. They are rather price-based, and more nebulously political. On the political front there is the environmental contingent that is wedded to particular 1970's based ideas (that are seeing a current resurgence), and not wholly disjointed from that movement there is a wider dislike for sending petro-dollars to distasteful foreign regimes. That's the 'energy independence' crowd. Coal dovetails with both those desires.
The energy independence bit is easy. The US has more energy reserves in the form of coal than Saudi Arabia has in oil. If you want to keep the money here, using US coal is one way to do it. In fact, the transformation of our economy since the 1970's is the reason that the current high prices of oil are not having the same deleterious effect of high oil prices after the Yom Kippur War (cf. #3 here, and supported here - in summary, we're just as energy dependant today, but it is now mostly electrical (60% of energy and GDP), which is nearly 100% non-oil based, and only minorly oil based (40% of energy but only 15% of GDP), although important for transportation).
The new shift is the greening of the coal industry. Scrubbers to eliminate sulfur (and mercury, etc.) from coal smokestacks have been required for all new sources for some time. The industry chose to fight the regulations tooth and nail, claiming that major repairs were minor repairs, and refusing to build new plants, to avoid the scrubber mandate (they are expensive). But that approach stymied the industry growth, so there was a shift to 'clean' coal, which meant 'low-sulfur' coal, since the smoke stack pollution monitoring could be satisfied with that feedstock even without the latest scrubber technology. Finally, some of the players have decided that instead of retrograde fighting, maybe they should just go with the spirit of the regulation and see if they can make a business model for it, and it turns out they can. The absurdity of this paradox is that the shift is now towards high sulfur coal.
The Wall St. Journal (sub. req.) did a nice job on this yesterday. They looked at 3 coal sources: Northern Appalachia [NA], the Powder River Basin [PRB], and Central Appalachia [CA] (see further review). The NA coal is high sulfur, and as a result has 40% more heat content than low-sulfur PRB coal, and 10% more heat content than low-sulfur CA coal, but sells for $53/ton, whereas PRB and CA coal sell for $55 and $71/ton, respectively, including transportation costs. So who wouldn't want to get 40% more heat for between 4% and 25% less, for a total $/btu differential of ca. 44-65%? The only problem is that using high-sulfur coal necessitates scrubbers, but for that price differential, it's worth it. Currently "...between 30% to 40% of the nations coal-fired electricity output is generated by facilities that use scrubbers, but that figure is expected to jump to about 60% during the next five years..."
So, that was a long-winded background (although much more could be said). We haven't completely decided if we are interested enough, but we may take a look at some coal producers.