In Perspective - Coal

Putting things in perspective sometimes takes a reference point. I thought I would use something that is known by almost every American, the Empire State Building. The weight of the building is 365,000 tons so keep it in mind when consumption numbers are mentioned.

Last week I mentioned the need for more electrical power over the next 40 years and one of the options is coal. In 2005 there were 614 coal-fired power plants in the U.S. and coal is the dirtiest of the carbon based fuels we use. Coal impurities range from trace quantities of many metals, including uranium and thorium, to much larger quantities of aluminum and iron, to still larger quantities of impurities such as sulfur. Products of coal combustion include the oxides of carbon, nitrogen, and sulfur; carcinogenic and mutagenic substances. Researchers have found that Americans living near coal-fired power plants are exposed to higher radiation doses than those living near nuclear power plants that meet government regulations.

Those of us that are old enough will remember a phenomenon called Acid Rain. Acid rain was traced primarily to coal fired power plants and what is amazing is that it is neighboring states west of us here in New York that give us acid rain. So what is acid rain? Acid rain is mostly caused by emissions of compounds of sulfur, nitrogen, and carbon which react with the water molecules in the atmosphere to produce acids which are transported by prevailing winds hundreds of miles away. The acidity of natural precipitation varies somewhat, it normally is around pH 5.6, the average pH of rainfall in New York State ranges from 4.0 to 4.5, which is up to 30 times more acidic than "normal." To return the quality of water in the Adirondacks to 1984 levels, nitrogen oxides and sulfur dioxide must be reduced by an additional 40 to 50 percent over current requirements.

Speaking of water, a typical 500-megawatt coal-fired power plant requires about 2.2 billion gallons of water each year from nearby lakes, rivers, or oceans, to create steam for turning its turbines. This is enough water to support a city of approximately 250,000 people. The EPA estimates that up to 1.5 million adult fish may become trapped against the intake structures and lost each year. Another point is that the water it returns to its source is hotter, by up to 20-25° F, than the water that receives, so it also affecting water quality and wildlife.

Other emissions that affect the environment and our health are many. A typical 500-megawatt coal plant creates waste that includes more than 125,000 tons of ash and 193,000 tons of sludge for a total of 318,000 tons from the smokestack scrubber each year. Nationally, more than three-quarters of this waste is disposed of in unlined, unmonitored onsite landfills and surface impoundments. Coal ash is composed primarily of oxides of silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury, and sulfur plus small quantities of uranium and thorium. In recent history the damages from these sludge dumps have caused considerable environmental and financial damage.

Estimated emissions produced by coal-fired generation of electricity in 2007 were 3.7 million tons of carbon dioxide, 10,000 tons of sulfur dioxide (SO²), 10,200 tons of nitrogen oxide (NOx) all of which contribute to acid rain. That doesn’t include 170 pounds of mercury, 1/70th of a teaspoon deposited on a 25-acre lake can make the fish unsafe to eat and 225 pounds of arsenic, which will cause cancer in one out of 100 people who drink water containing 50 parts per billion. 

We are consuming three times the amount of coal that we did 50 years ago totaling about 1.1 billion short tons. Putting that in perspective, a typical coal plant requires 14,600 railroad cars of coal a year, or a train about a 166 miles long. All 614 coal fired power plants in the U.S. would take a train 101,924 miles long or about 280 miles long each day.

There is no such thing as clean coal and clean coal technology is still a theory. It is also estimated that to add carbon capture to a power plant would cost around $1 billion per plant, if it works but according to the U.S. Department of Energy, it is not economical to retrofit existing coal plants with carbon capture technology. Most of the power plants in the U.S. are well over 30 years old. If we increase the number of power plants, due to demand, we have major issues that need to be addressed including pollution, water, fuel supply and air quality. One more point is that with the predicted increase in demand, we would have only a 60 to 70 year supply of coal, which will put us in another energy crisis in the near future.