Life Cycle Greenhouse Gas Emissions of Coal-Fired Electricity Generation

Systematic Review and Harmonization

Authors

  • Michael Whitaker,

  • Garvin A. Heath,

  • Patrick O’Donoughue,

  • Martin Vorum

Errata

This article is corrected by:

  1. Errata: Second corrigendum to: Whitaker, M., G. A. Heath, P. O'Donoughue, and M. Vorum. 2012. Life cycle greenhouse gas emissions of coal-fired electricity generation: Systematic review and harmonization. Journal of Industrial Ecology 16(S1): S53–S72 Volume 17, Issue 5, 789–792, Article first published online: 17 September 2013

Garvin Heath, National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401, USA. Email: garvin.heath@nrel.gov

Summary

This systematic review and harmonization of life cycle assessments (LCAs) of utility-scale coal-fired electricity generation systems focuses on reducing variability and clarifying central tendencies in estimates of life cycle greenhouse gas (GHG) emissions. Screening 270 references for quality LCA methods, transparency, and completeness yielded 53 that reported 164 estimates of life cycle GHG emissions. These estimates for subcritical pulverized, integrated gasification combined cycle, fluidized bed, and supercritical pulverized coal combustion technologies vary from 675 to 1,689 grams CO2-equivalent per kilowatt-hour (g CO2-eq/kWh) (interquartile range [IQR]= 890–1,130 g CO2-eq/kWh; median = 1,001) leading to confusion over reasonable estimates of life cycle GHG emissions from coal-fired electricity generation. By adjusting published estimates to common gross system boundaries and consistent values for key operational input parameters (most importantly, combustion carbon dioxide emission factor [CEF]), the meta-analytical process called harmonization clarifies the existing literature in ways useful for decision makers and analysts by significantly reducing the variability of estimates (−53% in IQR magnitude) while maintaining a nearly constant central tendency (−2.2% in median). Life cycle GHG emissions of a specific power plant depend on many factors and can differ from the generic estimates generated by the harmonization approach, but the tightness of distribution of harmonized estimates across several key coal combustion technologies implies, for some purposes, first-order estimates of life cycle GHG emissions could be based on knowledge of the technology type, coal mine emissions, thermal efficiency, and CEF alone without requiring full LCAs. Areas where new research is necessary to ensure accuracy are also discussed.

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