The following is part one in a three-part series examining factors inhibiting the addition of coal-fired generation capacity in the U.S. This story explores what is considered "state of the art" technology for coal generation and the challenges facing developers. The second installment will look at the Chinese policies that have boosted coal and the market conditions currently disadvantaging new capacity running on that fuel in the U.S., while the third story will cover the politics of coal and what would be needed to get a new power plant built.
The Kemper County carbon capture power plant in DeKalb, Miss. Source: AP photo
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With her glasses resting low on her nose, Sen. Shelley Moore Capito, R-W.Va., held her hands up in apparent exasperation as she questioned an expert on emerging coal generation technology: "Where do you see the future of supercritical coal plants in this country? Can we get there? Or is China going to continue to eat our lunch in this area?"
Capito asked those questions during a hearing held by the Senate Committee on Environment and Public Works in November 2017. The expert, Kipp Coddington of the University of Wyoming's Carbon Management Institute, responded by saying he is confident in the technology and touting the advancements being made in the U.S. Coddington further said he believes that policy could be developed to encourage the construction of new coal plants, despite competition from cheaper natural gas.
Many experts point to the most recent Lazard report on the unsubsidized levelized cost of energy, which showed that prices for natural gas combined-cycle generation, as well as wind and certain other renewable resources, have fallen below the price for coal-fired generation. Moreover, gas-fired and renewable resources generally emit either less pollution than coal or no pollution at all, which is a quality the public is finding increasingly desirable.
But looking more closely at some of the additional forces hampering the addition of new coal capacity reveals a far more complex answer to Capito's questions. Engineering challenges and a lack of U.S. manufacturing abilities also have weighed down options for new coal plants, despite their receiving political support from Washington D.C., an S&P Global Market Intelligence investigation found.
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State-of-the-art
A handful of new coal-fired generators have been added to the nation's generation mix over the past decade, but two — the Prairie State Energy Campus in Illinois and the Longview power plant in West Virginia, in Illinois and West Virginia — often are referred to as state-of-the-art facilities.
James Wood with West Virginia University is director of the U.S.-China Clean Energy Research Center's Advanced Coal Technology Consortium, a joint research venture of the U.S. and Chinese governments. He calls the Longview facility the most efficient power plant in the Western hemisphere; so efficient that it is considered a must-run power plant, dispatched along with nuclear facilities on the PJM Interconnection grid. The plant operates at about 40% efficiency, compared to the U.S. fleet average of 33%, and often is visited by dignitaries and researchers such as Energy Secretary Rick Perry, who toured it in July.
"In my view, they have set the new [best available control technology] for the next coal-fired power plant," said Wood, who served as deputy assistant secretary for clean coal with the Office of Fossil Energy under former President Barack Obama's first energy secretary, Steven Chu. "I think it is the cleanest [coal] power plant in the world per megawatt hour."
According to Longview Power LLC COO Steve Nelson, the power plant has proven that coal-fired generators can meet environmental regulations and compete in the market.
Longview features an advanced supercritical pulverized coal boiler that drives the plant's high efficiency by using high levels of pressure and heat to push water into a supercritical state, meaning no clear distinction exists between its liquid and gas phases.
Like more traditional steam generators, supercritical power plants such as Longview use the heated water to turn a turbine in a process referred to as the Rankine cycle. Wood said that process is not the most efficient way to generate power but nevertheless has become the industry standard because it is economic.
When Wood says the U.S. fleet average is 33% efficient, that means 67% of the energy involved is lost in the combustion process. That is a statistic researchers such as Wood are trying to improve. Increasing efficiency is a simple concept; raise the heat of the water and the plant can generate more megawatts per ton of coal, he said.
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Made in the USA?
China easily is ahead of the curve with respect to new coal technologies. The country's fleet efficiency is around 40%, Wood said, but some of its individual power plants have reached as high as 45%. So, why has the U.S. been unable to follow China's lead, especially since Longview has been so successful?
Wood said the U.S. has yet to develop materials that can withstand the high temperatures and pressure typical of supercritical power plants and also last 20 to 30 years. The materials need to be developed, tested and approved by the American Society of Mechanical Engineers, and Wood believes that no such process is underway to certify American-made boilers.
Longview's boiler equipment was built at a manufacturing facility in China by American manufacturer Foster Wheeler, Nelson said. While manufacturing in China may have lowered labor costs, Longview had to employ American and European quality-control processes to ensure the facility would meet requirements back home, he said.
"The Chinese are still challenged around adopting good quality control, but the global economy around manufacturing is there to control quality," Nelson said.
Since Longview's boilers arrived in West Virginia, the company has worked to improve the design and smooth out some construction-related defects, Nelson continued. Noting that the facility employs German technology and that Longview has used its "know-how" to customize the equipment to fit its needs, he said, "We've kind of turned our Mercedes Benz into a Chevy in many ways."
The MacGuffin
Other technologies are being researched for coal generation, but Wood said that if he were to build a coal plant today, his most likely choice would be some sort of supercritical technology, similar to what is available now but employing post-combustion carbon capture.
Wood said CCS brings down the efficiency of a power plant by about 5%, so new power plants still would need broader efficiency improvements to make them competitive. He sees progress in CCS technology being made with NET Power LLC's 25-MW (50 MW thermal) natural gas CCS demonstration project in Texas. Backed by Exelon Corp., the project will feature the Allam Cycle, which uses CO2 as a "working fluid" to drive a combustion turbine, producing pipe-ready CO2 that can be either stored or captured and used in enhanced oil recovery.
Wood also believes that more research needs to be focused on uses for captured carbon. He anticipates that carbon capture from power plants will play a larger role in the next decade or so for enhanced oil recovery.
"Once you start seeing a market-determined price for CO2, there may be some people willing to go ahead and try to capture the CO2 from industrial processes that produce it," Wood said.



