Is Coal a Fuel of the Future?
Few reasonable people can dispute that the EPA is conducting a war against coal.
A large number of new regulations affecting coal-fired power plants have been proposed in rapid-fire succession by the EPA.
The rapidity with which they have emerged and the short time allowed for implementing corrective action, have made it virtually impossible for utilities to respond rationally except to consider shutting down plants and removing them from service.
The good news is that older and less utilized coal-fired power plants can be retired without seriously affecting the availability of affordable electricity – providing the EPA doesn’t force the retirement of coal fired power plants too quickly.
The bad news is that EPA regulations also threaten newer plants and deter the building of modern, highly efficient ultra-supercritical coal-fired power plants to replace the older, less efficient plants that are retired.
Studies have attempted to quantify the number of plants that would be closed over the next ten years as a result of EPA rules.
An analysis by the Editor in Chief of Power Magazine developed a rational approach for identifying plant closures and found that many existing older plants could be closed without seriously affecting the availability of electricity – providing the plants aren’t closed too quickly. This is the best analysis I have seen on this subject.
This analysis identified 305 units built before 1960 that didn’t have Flue Gas Desulfurization (FGD) and Selective Catalytic Reduction (SCR).
Since capacity factor is an indication of how intensively a power plant is utilized, low capacity factors would suggest that plants could be retired without affecting the availability of electricity – providing new peaking units are built to provide power during peak periods, such as on hot summer days where air-conditioning increases electricity usage.
Out of the 305 plants built before 1960, as described above, 167 have capacity factors of 50% or less. If all 167 plants were closed, only 4.2% of gigawatt hours would be lost from coal-fired power plants.
Similarly, 85 plants have capacity factors of 40% or less, and if all these plants were closed, only 1.1% of gigawatt hours would be lost.
Even if all 305 plants were closed, only 11.9% of generation in gigawatt hours would be lost from coal-fired power plants, and this represents only 5.8% of our annual demand for electricity.
There are reasons why some of the 305 units would be repowered or have air quality equipment installed and therefore not be considered for retirement, but it’s clear that a large number of the 305 plants built before 1960 could be retired without affecting the availability of affordable electricity.
With cap and trade essentially dead, there is no reason to keep these units open for use as chips for securing carbon credits.
In other words, a rational business case can be made for closing a significant number of older coal-fired power plants in an orderly manner.
New EPA rules with respect to once-through water cooling and wet ash handling, will also threaten units built after 1960 with closure.
The EPA war against coal, therefore, goes beyond what could be decided on the basis of a rational business decision.
In addition to promoting the closure of coal-fired power plants, the EPA’s war against coal deters the building of new, efficient coal-fired power plants and thereby threatens the availability of affordable electricity.
As President Obama said, companies could build coal-fired power plants, but they would go bankrupt.
If it weren’t for EPA regulations, ultra-supercritical coal-fired power plants would be logical replacements for retired coal-fired power plants.
Market forces should be allowed to determine which type of power plant is built to supply Americans with electricity.
Currently the overnight cost for building an ultra-supercritical power plant is approximately $2.800 per KW. This is a little more than twice the cost of a natural gas combined cycle (NGCC) power plant.
While the cost of natural gas is low, as it is now, it’s likely that NGCC plants would prevail. When the price of natural gas increases, ultra-supercritical coal-fired power plants could be the preferred choice.
Ultra-supercritical coal-fired power plants operate at very high temperatures and pressures. They are substantially more efficient than existing subcritical coal-fired power plants. The average existing subcritical plant has a thermal efficiency of 33% HHV. The only ultra-supercritical plant being built in the United States is designed to have a thermal efficiency of 42% HHV.
Advanced ultra-supercritical plants are expected to have a thermal efficiency of around 47% HHV. This is over 40% more efficient than existing subcritical coal-fired plants.
China is building around twenty ultra-supercritical coal-fired power plants. Japan has also built several ultra-supercritical plants. Even Europe, with its extreme environmental rules, is building ultra-supercritical units.
The higher thermal efficiencies of these units have corresponding reductions in fuel and water use.
Interestingly, advanced ultra-supercritical coal-fired power plants will have about the same CO2 emissions as natural gas units.
While it’s entirely feasible to retire significant numbers of existing coal-fired power plants and have NGCC units taking up the slack in the near term, it will be necessary to build ultra-supercritical coal-fired power plants to provide the base load, low-cost electricity needed for a sound U.S. economy.
Coal and natural gas will be the fuels of the future – if we are to have a plentiful supply of low-cost electricity.
Next Tuesday I’ll comment on how those responsible for operating the electric grid have responded to the EPA’s demand for rapid closure of coal-fired power plants. They are very concerned about grid reliability because of the EPA’s new rules.
Note: The analysis, Predicting U.S. Coal Plant Retirements, By Dr. Robert Peltier, PE is available at http://www.powermag.com/issues/features/Predicting-U-S-Coal-Plant-Retirements_3632.html
Note: HHV = High Heating Value
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