In thinking about coal, it is useful to separate the problem into two pieces: mining and extraction, and electricity generation. In a previous post, I examined technologies for coal-powered electric plants that use sequestration to ensure that emissions are captured and stored underground. None of the touted "carbon sequestration" or "clean coal" technologies have been deployed in a commercial plant and doing so would naturally add to the cost per KWH.
The cost of mining and extraction is where traditional accounting falls short. First off, how is coal extracted?
... Early coal mining was almost exclusively done in deep shafts that led to thick (5-10 feet) coal seams, which were blasted and picked out and loaded on rail cars to be drawn out of the mine by mules. Miners worked in dark, dusty conditions always at the risk of fatal roof falls and methane gas explosions. Beyond the risk of sudden death or serious injury, miners also faced the prospect of black-lung disease if they spent years in the profession.The current approaches involve either removing entire mountain tops or dislodging mile-long underground seams! Unless the mining companies are voluntarily estimating the cost of these forms of environmental degradation, the cost of electricity from coal as quoted in media reports, is not accurate. The list of environmental problems associated with coal mining is depressing. Here is one I ran across from the Union of Concerned Scientists:
Deep mining has indeed come a long way. Today, miners use a technique called long-wall mining, which involves a long (up to a mile) face of an underground coal seam which is dislodged by a saw that runs on tracks along the face. This method is much more efficient at removing thick coal seams than the old blast-and-pick method, and accounts for half to two-thirds of current Appalachian coal production. While some dangers are now less, current underground mining still results in fatal roof fall and explosion accidents.
Surface mining, or strip mining, has become more and more popular in recent decades, especially in removing thinner seams of coal (as little as a foot thick). The most recent innovation in strip mining is known as mountaintop removal. It peels back a mountain, layer by layer, by alternately blasting the thick layers of rock away from the coal seams and then scraping the coal seam out and hauling it away in huge dump trucks. Much of the “overburden” rock (the non-coal layers) is pushed off into adjacent valleys. As much as 500- to 1,000-vertical feet of a mountain may be removed in the process and valleys are filled in to depths of as much as 500 feet by the rubble.
MININGThe main problem with both mountain top removal and long-wall mining is that landscapes are permanently altered as a result of coal mining:
Altered landscapes. Surface mining in Appalachia often removes entire mountaintops and dumps the wastes into valleys and streams; between 1985 and 2001, more than seven percent of the region's forests were cut down and more than 1,200 miles of its streams buried or polluted. In addition, waste materials from underground mining are placed in large piles above ground, which can also scar the landscape and alter stream flow.
Water contamination. Acids and toxic metals can contaminate surface and groundwater, harming aquatic life and rendering water supplies undrinkable.
Safety hazards. Underground mining accidents result in many deaths and injuries, and coal dust inhalation causes chronic health problems. Black lung disease still kills about 1,000 former coal miners in the United States each year.
Water contamination. Impurities such as acids and heavy metals removed from coal and stored in slurry reservoirs canleach into surface and groundwater.
Safety hazards. Slurry reservoir dams can fail, flooding local waterways and putting both wildlife and downstream communities at risk.
... The coal in the Appalachian Mountains is hard to extract because it is buried under layers of shale and sandstone hundreds of feet thick. A few decades ago, strip miners would cut along the edge of a ridge side, then auger into a coal seam. But today, with bigger machines and little moral or regulatory constraint, coal operators simply blast away the entire mountaintop -- its forests, capstones, and topsoil -- so they can scrape out thin seams of low-sulfur coal. Nearly everything else is dumped into the valleys below, often burying pristine headwater streams. The resulting "valley fills" create the largest man-made earthen structures in the country -- huge treeless funnels that let mud and rainwater wash unimpeded through low-lying communities all across central Appalachia. The town of McRoberts, Kentucky, recently endured three "100-year floods" in 10 days. The water filled homes and carried away carports. When TECO Energy of Tampa, Florida, had leveled every peak around the community, it took the coal, took the profits, and left the people of McRoberts with crumbling homes, terrible roads, and a constant fear of being washed away in one’s sleep.One may be able to clean up coal-powered plants, but can one mine for coal without destroying the environment? Coal isn't as cheap as it appears, if anything the true cost of mining it probably makes it one of the most expensive energy sources. Using the Triple Bottom Line (People, Planet, Profits), coal costs a heck of a lot more than renewable energy sources.
According to the Environmental Protection Agency, in addition to the more than 700 miles of streams buried by valley fills, thousands more miles have been contaminated with sediment, heavy metals, and acid mine drainage, a toxic orange syrup that kills everything in its path. And these are headwaters, so their contamination affects all life downstream. In Letcher County, Kentucky, children suffer extremely high rates of diarrhea, vomiting, nausea, and shortness of breath, all of which can be tied to dissolved minerals in nearby streams. Presumably the Clean Water Act was established to prevent such degradation. But early in the Bush administration, coal lobbyist Steven Griles was named a deputy secretary at the Department of Interior. Officials changed one word of the act -- replacing "waste" with "fill" -- so that toxic mining debris could be dumped into rivers as benign fill material.
There will soon be enough flattened mountaintops in Appalachia -- 1.4 million acres -- to set down the state of Delaware on former summits. Try driving across the 10,000-acre wasteland that surrounds Larry Gibson’s home on Kayford Mountain, West Virginia. Hundreds of people, like the photographer J. Henry Fair, make that trip every year to see, in Gibson’s words, "what hell looks like." Kayford Mountain, more than any place I know, illustrates the power and the willingness of some human beings to convert the natural world into money and "cheap energy" as quickly as possible. If that means the total destruction of an entire region, its people, and its culture, so be it.
And yet the majority of Americans have never heard of mountaintop removal.
Coal is touted as the cheapest source of (abundant) energy around, and in this post I argue that coal is actually quite expensive. From a power generation and emissions perspective, will "clean coal" and "carbon sequestration" be as cost-effective as current renewable energy sources? No commercial plants have been deployed so cost estimates are mere guesses at this point. Given the growth in coal usage in China and India, developing "clean coal" power plants is extremely important.
More importantly, Coal is cheap because the environmental costs of mining and extraction are more or less ignored. How cheap would coal mining be if it were held to the standard that it should be?
Hopefully the current excitement surrounding renewable energy, plus a heavy dose of energy efficiency and conservation will lead to less coal in the future.
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