Modern Coal-Fired Power Plants

Modern Coal-Fired Power Plants…

(The following article was published in September 2017 and is still relevant today. It is repeated now, with updates, by an associate, while I do not have access to the Internet.)

Ultra-supercritical coal-fired power plants deserve clarity. 

Recently, an editor dismissed ultra-supercritical coal-fired as jargon, and asked: Is there really something called an “ultra-supercritical” power plant? 

Yes, there is: And everyone, engineers, and average people, deserve an explanation about why they are such a significant improvement over the coal-fired power plants built in the past. 

They are called ultra-supercritical because they operate at very high temperatures and pressures that have been made possible by recent advances in metallurgy. 

They operate at 4,350 psi, and 1,112°F, with efficiencies of 44% HHV (high heating value). Ultra-supercritical (USC) steam generally refers to supercritical steam at more than 1,100 degrees F. Supercritical refers to when the steam undergoes a transition from a mixture of water and steam, to vapor with corresponding changes in physical properties. 

While engineers are interested in the technical details, everyone should be interested in the increased efficiency. 

In fact, USC plants are now being referred to as high-efficiency low emission (HELE) power plants.

Virtually all of the existing coal-fired power plants in the United States operate at an efficiency of only 32% HHV. 

Ultra-supercritical, i.e., HELE, plants with an efficiency of 44% are, therefore, nearly 40% more efficient than all but one of the existing coal-fired power plants in the United States. 

This means they use roughly 40% less coal and emit approximately 40% fewer emissions, including CO2. 

Ultra-supercritical, i.e., HELE,  coal-fired power plants are an important improvement over existing coal-fired units. While they are more costly to build than traditional supercritical plants, they cost half as much as nuclear or integrated gasification combined cycle (IGCC) power plants.

The only HELE plant built in the United States is the John W. Turk, 600 MW plant in Fulton, Arkansas.

Currently, no new coal-fired power plants can be built in the United States because EPA regulations limit CO2 emissions. HELE plant CO2 emissions are slightly above the 1,400 pounds per MWh limitation imposed by the EPA. 

Coal is an important resource, with the United States having reserves that could last 400 years. 

Coal, together with natural gas, can provide inexpensive baseload power for all Americans. 

Ultra-supercritical, i.e., HELE, coal-fired power plants are a significant improvement over existing coal-fired power plants. See, Why HELE Matters

Additional improvements are on the way with USC plants that can operate at even higher temperatures and pressures, and with corresponding additional improvements in efficiency. 

The new administration should move quickly to clear the way for these new, and more efficient, coal-fired power plants. 

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