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The Answer to Coal Climate Pollution Is Natural Gas and Carbon Capture, EPA Says



Courtesy of EPA

The Environmental Protection Agency has new rules for how much carbon dioxide power plants can spew. Designed to ensure that no new plants built in the U.S. can be highly polluting, the regulations would prohibit the dirtiest coal-fired power plants without additional technology to capture and store CO2. The trouble is: hardly any such coal-fired power plants are being built in the U.S.

This year, two new coal-fired power plants have been completed. Next year, that number may well be zero, the long term projection from EPA for how many coal plants without climate pollution control technology will be built. The exceptions will be the new coal-fired power plants that already incorporate CO2 capture and storage, like the Kemper Plant in Mississippi or the Texas Clean Energy Project under construction. But this is not because of the new EPA rules for the most part. It is because it is cheaper (and easier) to build a new power plant that burns natural gas instead.

Perhaps not coincidentally, new EPA rules for CO2 emissions are set at the level that natural gas-burning power plants already achieve. In other words, to meet this new standard gas power plants have to do nothing. The rule stipulates that natural gas must not emit (on average) more than 1,000 pounds per megawatt-hour while coal plants must not emit more than 1,100 pounds per megawatt-hour averaged over a year (a change from the original proposal that had both types of power plants meeting the same standard).


"PC" stands for pulverized coal and "NGCC" stands for natural gas combined cycle. As the chart shows, CCS or natural gas are the answer to meeting the EPA's new power plant emission standards. Courtesy of the National Energy Technology Laboratory

This is hardly a ground-breaking effort to combat climate change. Natural gas itself is largely methane, a potent greenhouse gas. But burning methane produces roughly half the CO2 emissions of burning coal. As the EPA puts it: "there will always be incremental climate and human health benefits [from] a new natural gas combined cycle unit relative to a new coal unit." But such a power plant still produces nearly 2 million metric tons of CO2 per year. So, although natural gas is cleaner than coal, one day even natural gas power plants will require CO2 capture and storage technology.

There's good news on that front. The technology exists and has been used for years. There was even a near full-scale demonstration project in West Virginia—the heart of coal country—that ran for a few years with success. That project shut down because the technology, obviously, costs more than just freely spewing CO2 into the atmosphere as is currently done. The utility didn't want to pay that extra cost, the federal government didn't want to pay that extra cost and the local governments refused to force customers to pay that extra cost. That problem hasn't gone away though the U.S. Department of Energy is currently offering $8 billion in loan guarantees for this type of project.

The new standards (peruse them below) would also only require what the EPA is calling "partial CCS," that is a coal-fired power plant wouldn't need to capture all of its climate altering CO2, just somewhere between 30 and 50 percent, depending on the type of unit. So a coal-fired unit that currently spews around 4 million metric tons of CO2 per year would emit no more than 3 million metric tons per year to comply with this rule. As a result, even EPA officials and the standards themselves admit that these rules will not produce any reduction in CO2 pollution that is being emitted now.

EPA-New-Power-Plant-CO2-Proposal_9-20-13 (PDF)

EPA-New-Power-Plant-CO2-Proposal_9-20-13 (Text)

EPA Administrator Gina McCarthy noted at the National Press Club on September 20, however, that the new standards lay out a path forward for coal in a carbon constrained world—the ubiquitous acronym CCS—a sentiment shared by her counterpart Energy Secretary Ernest J. Moniz. But these rules don't apply, at all, to the 1,400 old coal-fired boilers in the U.S., not even those "undergoing modifications or to reconstructed units," even though such units are responsible for nearly 40 percent of U.S. CO2 pollution. We've seen this before. When new rules came in for SO2 pollution to cut back on acid rain, old coal-fired power plants enjoyed an exemption. So, instead of retiring old coal-fired power plants, industry kept running and running and running them. Many of them, some built in the 1930s and 1940s, are still burning coal today.

The EPA is expected to propose rules for these old plants in 2014, about the same time this rule for new plants may become law, barring inevitable delays due to lawsuits. Then and only then will we know how serious the putative "war on coal" is.

Regardless, the rules for existing plants will ultimately be set by states on a state by state basis, while complying with an overall EPA standard. With other types of pollution, this has led to far different standards for SO2 in New York than in Ohio, for example. But it doesn't matter where a molecule of CO2 is emitted to the atmosphere and an individual molecule can persist for hundreds of years. The states will also decide who gets to pay for this new CCS technology.

And only when CO2 rules for new power plants drop below the levels achieved already by natural gas power plants will we know how serious the U.S. government is about reducing greenhouse gas concentrations—which touched 400 parts-per-million in the atmosphere for the first time in human history this past May.

The views expressed are those of the author and are not necessarily those of Scientific American.

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