Coal burning doesn’t have to worsen climate change if new ways of capturing and storing carbon can be found, says an MIT report.
Jennifer Weeks
Current efforts to demonstrate that carbon dioxide from coal-fired power plants can be captured and stored underground on a large scale are “completely inadequate” and the U.S. government should increase funding for and speed up the development of a wider range of new carbon-capture and sequestration (CCS) technologies, according to a study released yesterday written by a panel of MIT faculty.
The report, The Future of Coal, examines technical, economic, and political aspects of the world’s reliance on coal, which accounts for 25 percent of world energy demand and generates 50 percent of the U.S. electricity supply. Panel co-chairs John Deutch, a chemistry professor, and Ernest Moniz, professor of physics and engineering systems, have both served as Under Secretary at the U.S. Department of Energy (DOE) and in other senior government positions. They wrote an influential report in 2003 on nuclear power and this latest study is likely to focus greater attention on CCS technologies.
Geoscientists agree that climate change is underway, the result of massive releases of greenhouse gases from the burning of coal and other fossil fuels. This has prompted calls for greater investment in renewable energy technologies like solar power. But this study assumes that coal use will continue to grow worldwide, because coal is abundant and the cheapest of all fossil fuels. So the development of carbon-capture technologies is critical for slowing down climate change, the study says.
“I think their big conclusions are the right ones,” says John Holdren, professor of environmental policy at Harvard’s Kennedy School of Government and president of the American Association for the Advancement of Science. “It’s crucial that we ramp up efforts to develop, prove, and deploy CCS technology, and that the price put on carbon is high enough to motivate use of the technology.”
Catch that gas
Conventional power plants burn pulverized coal in boilers and send the resulting flue gas through a process that removes sulfate, nitrogen oxide, and particulates. In a CCS system, CO~2~ would be chemically separated from the flue gas and compressed into a supercritical fluid for storage. Such a system, which is not currently in use on a commercial scale, would increase the cost of producing electricity. But the MIT study estimates that a tax on carbon emissions could make new coal plants with CCS technologies cost-competitive with conventional systems.
The report also recommends a geological research program to analyze underground reservoirs for their ability to store large amounts of carbon dioxide. Many promising sites exist, the authors write, and demonstration projects in other countries, such as Norway, Canada, and Algeria, are each injecting about one million metric tons of CO~2~ underground annually.
Current DOE pilot projects are too small, the report says. It recommends creating at least three large-scale demonstration projects in the U.S. that would last five years or more, and about 10 around the world.
The report shies away from recommending a particular technology for future coal power plants, saying that different technologies need further testing and evaluation in combination with carbon-capture technologies. This move disappointed some advocates, who say that energy companies need to be given clear direction on how to design future coal plants so that they can be easily retrofitted with CCS technologies.
“There are plenty of cases where industry said something wasn’t possible but government mandated a technology standard, stood firm, and allowed enough lead time. And the companies achieved it,” says Seth Kaplan, clean energy and climate change program director at the Conservation Law Foundation, a Boston-based environmental advocacy group.