What is all the fuss about coal and the environment? For decades, the U.S. and other developed countries have been using coal as their primary fuel to produce most of their electric power. Each year, there have been incremental process improvements to reduce coal's impact on air, land and water. Nevertheless, when compared with alternatives, the progress has not been enough.
The primary product of a coal-fired power plant is not energy; it is waste and pollution. The secondary product is electric power. Engineers are losing an age-old battle to overcome the basic laws of physics.
Most of a coal plant's economic loss is from heat. At least two-thirds of the energy consumed by coal plants and other steam plants is wasted. Most of that waste is in the form of heat. Perhaps this is why a power plant's fuel efficiency is often designated as its "heat rate."
From a utility's perspective, most of the heat wasted by its power plants is uneconomic. As with all other wastes, utilities must find ways to remove residual heat. The most effective method to remove waste heat is to use water to move residual heat from the turbine and dump it into the atmosphere, river, lake or ocean. Coal-fired power plants and other steam plants require massive amounts of cooling water.
Every hour that a plant is producing power, billions of British thermal units (Btu) of waste energy are dumped into the environment. For example, a 500-megawatt coal plant produces about 1,000-megawatts of waste heat.
This is in addition to the tons of nasty fly ash that also needs to be collected, transported and disposed. Fly ash is the dirt that remains after coal is burnt. Like most other mined products, coal is mixed in with all sorts of dirt, minerals and organic compounds.
Coal-fired power plants produce millions of tons of fly ash every day. Every train that delivers coal to a power plant returns with carloads of fly ash and other solid waste materials.
Some fly ash is used as aggregate in paving materials. Some coal-burning products are used in manufacturing drywall and ceiling tiles. The rest finds its way to abandoned coal mines, landfills and repositories.
While cheap land has been used as a dumping ground for the coal industry's solid wastes, the atmosphere has been used as a free dumping ground for other wastes. Coal-fired power plants use tall smokestacks to jettison other wastes high into the air.
Most are aware that coal-fired power plants emit massive amounts of carbon dioxide and carbon monoxide. But when it comes to air emissions, coal-fired power plants dump far more than carbon. They also send small particles high up into the atmosphere. The technical term for these emissions is particulate matter, or simply PM.
Particulate matter lodges itself into the eyes and lungs. Its chemical composition is similar to that of fly ash; it often contains all sorts of chemical compounds. When inhaled, these compounds may embed themselves into lungs or pass through into the bloodstream.
The U.S. has challenges with particulate matter. The ambient air in California, Nevada and Arizona carries health-affecting levels of heavy particles (10 microns and less). Ambient air in Georgia, Tennessee, the Midwest and the East has more counties affected by unacceptable levels of lighter particles (2.5 microns and less).
Some coal-fired power plants have a history of emitting volatile organic compounds, mercury, sulfur oxides, nitrous oxides and other toxins.
Until recently, states and local governments have been forced to accept a compromise: cheap power in return for pollution. Today, there are better alternatives. One is natural gas. Another is nuclear. Still others are wind, solar and renewable sources of energy
Natural gas offers huge improvements over burning coal. Modern gas turbines manufactured by General Electric (GE), Siemens (SI), French-based Alstom, Mitsubishi and others produce much lower levels of waste heat. They produce lower levels of carbon dioxide and lower levels of carbon monoxide. They produce no fly ash and only miniscule amounts of particulate matter.
At the state level, it is not always a partisan issue. States that have high levels of pollution are compelled to act. Not only do their own citizens demand a healthy environment, states cannot issue air, water or land permits for counties that are already over their limits.
The easy target is coal-fired power plants. If a state can encourage a utility to eliminate the right old coal plant and replace it with natural gas, wind or solar, the state wins. Businesses and voters win too.
At the time of publication, Glenn Williams had no position in any of the stocks mentioned.