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Exporting US coal to Asia could lower emissions

World Coal,

A new study, conducted by Duke University, claims that, under the right scenario, exporting US coal to power plants in South Korea could lead to a 21% reduction in greenhouse gas emissions, compared to burning the fossil fuel at coal-fired power plants in the US.

“Despite the large amount of emissions produced by shipping the coal such a long distance, our analysis shows that the total emissions would drop because of the superior energy efficiency of South Korea’s newer coal-fired power plants,” said Dalia Patiño-Echeverri, assistant professor of energy systems and public policy at Duke.

For the reduction to occur, US plants would need to replace the exported coal with natural gas. In South Korea, meanwhile, the imported coal must replace other coal as the power source. However, if imported US coal were to replace natural gas or nuclear generation in Korea, the emissions produced per unit of electricity generated would increase, Patiño-Echeverri said.

“This significant difference in results highlights the importance of analysing domestic energy policies in the context of the global systems they affect,” Patiño-Echeverri said.  

Rise in US coal exports

Stricter emissions requirements on coal-fired power plants, together with low natural gas prices, have contributed to a recent decline in the use of coal for electricity generation in the US. Faced with a shrinking domestic market, many coal companies are taking advantage of a growing export market.

US coal exports hit an all-time high in 2012, fuelled largely by demand in Asia. US coal exports to Asian countries have tripled since 2009.

Patiño-Echeverri and her colleagues published their findings this month in the peer-reviewed journal Environmental Science & Technology.

Not business as usual

To conduct their analysis, the team at Duke performed lifecycle air-emissions and economic assessments of two scenarios: a business-as-usual scenario, in which coal continues to be burned domestically for power generation at power plants in the US Northwest after they have been retrofitted to meet EPA emissions standards, and an export scenario, in which the coal is shipped to South Korea. For the export scenario, they focused on the Morrow Pacific Project being planned in Oregon by Ambre Energy. Under the project, Ambre would ship 8.8 million tpa of Powder River Basin coal to Asian markets using rails, river barges and ocean vessels.

Ambre Energy has since run into difficulties in gaining the necessary regulatory permission to build the project. The company was recently denied a construction permit for the coal export terminal project and this has since put doubt in the viability of the plan. However, Ambre Energy is expected to appeal the decision.

In the export scenario as the Duke team had it, emissions of “equivalent carbon dioxide” – a scientific measure of the coal emissions’ total global warming potential over a 100-year period – dropped 2%.

Other harmful emissions, including sulfur dioxide, nitrogen oxide and particulate matter, dropped similarly.  

“In addition to these benefits, our analysis shows that the export scenario would generate more than US$ 25 billion in direct and indirect economic activity in the US,” Patiño-Echeverri said. “It would also directly or indirectly create nearly US$ 6 billion in total employee compensation, US$ 742 million in new tax revenues, and roughly US$ 4.7 billion in profits for all sectors involved.”

In need of fine-tuning

Promising though these results are, “it’s too early to give the export scenario an unequivocal green light,” she said.

Further studies are needed to assess the export scenario's full environmental impacts, including water use, land use, the loss or degradation of vital fish and wildlife habitats, and risks associated with extraction and wastewater disposal of US shale gas deposits. Fine tuning is also needed, according to Duke University, in regard to the economic aspect of the study.

Patiño-Echeverri said the team’s projections are limited in precision, due to uncertainty surrounding the Morrow Pacific Project. As more specific information about the project is released, calculations can be updated to present a clearer picture of the impacts the project may have on the US energy system and global environmental conditions.

“It’s important to note that this is just one scenario. The export of coal to different markets, under different conditions, might yield very different results,” Patiño-Echeverri said. “Our work does not provide a carte blanche for all energy export projects, but it does give us a framework for comparing their impacts and making smarter economic and environmental policy decisions.”

Support for the study came from the Center for Climate and Energy Decision Making (SES-0949710), which is funded by the National Science Foundation.

Written by Sam Dodson

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