Implications of Near-Term Coal Power Plant Retirement for SO2 and NOX and Life Cycle GHG Emissions

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• 作者：Aranya Venkatesh ; Paulina Jaramillo ; W. Michael Griffin ; H. Scott Matthews
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：September 18, 2012
• 年：2012
• 卷：46
• 期：18
• 页码：9838-9845
• 全文大小：414K
• 年卷期：v.46,no.18(September 18, 2012)
• ISSN：1520-5851

文摘

Regulations monitoring SO₂, NO_X, mercury, and other metal emissions in the U.S. will likely result in coal plant retirement in the near-term. Life cycle assessment studies have previously estimated the environmental benefits of displacing coal with natural gas for electricity generation, by comparing systems that consist of individual natural gas and coal power plants. However, such system comparisons may not be appropriate to analyze impacts of coal plant retirement in existing power fleets. To meet this limitation, simplified economic dispatch models for PJM, MISO, and ERCOT regions are developed in this study to examine changes in regional power plant dispatch that occur when coal power plants are retired. These models estimate the order in which existing power plants are dispatched to meet electricity demand based on short-run marginal costs, with cheaper plants being dispatched first. Five scenarios of coal plant retirement are considered: retiring top CO₂ emitters, top NO_X emitters, top SO₂ emitters, small and inefficient plants, and old and inefficient plants. Changes in fuel use, life cycle greenhouse gas emissions (including uncertainty), and SO₂ and NO_X emissions are estimated. Life cycle GHG emissions were found to decrease by less than 4% in almost all scenarios modeled. In addition, changes in marginal damage costs due to SO₂, and NO_X emissions are estimated using the county level marginal damage costs reported in the Air Pollution Emissions Experiments and Policy (APEEP) model, which are a proxy for measuring regional impacts of SO₂ and NO_X emissions. Results suggest that location specific parameters should be considered within environmental policy frameworks targeting coal plant retirement, to account for regional variability in the benefits of reducing the impact of SO₂ and NO_X emissions.