Probably most of us think of underground coal mines with donkeys and canaries. Okay, at least underground.
The efficiency of the surface mine on the left should be apparent from the photograph. Really big trucks and excavating machinery can produce gargantuan mountains of coal.
Two Wyoming Mines Account for 20% of U.S. Coal Production should not be too surprising. In fact, 9 of the top 10 producing coal mines are in Wyoming. In the event you are planning your summer vacation, the two top mines are North Antelope Rochelle, and Black Thunder.
Just because nature works that way, you would also expect that this easily mined coal is not as good as the coal produced in the underground mines of Kentucky or West Virginia. (October Sky has been showing on cable the past month - the story of Homer Hickam who became a rocket scientist instead of a coal miner.) Indeed the coal in Wyoming is largely sub-bituminous. Wikipeda tells the ranking of coal (from least to best) is peat, lignite, sub-bituminous, bituminous, and anthracite.
At the beginning of the month, I posted Organic Mercury - Much Worse Than Natural Mercury, which describes the generation of methyl mercury that enters the food chain. The origin of most organic mercury is from coal-burning equipment. Mercury in U.S. Coal tells that mercury is largely uniform in density across the grades of coal. Since much more lower-energy coal has to be burned for the same energy than the higher grades, sub-bituminous coal results in more mercury released into the environment.
Because of the lower energy density of Wyoming coal, it is currently priced about $10.25 a ton. Transportation costs to deliver the Wyoming coal to the Southeast or Ohio Valley can be as much as $25 to $35 a ton.