Life cycle greenhouse gas emissions from electricity generated from shale gas are similar to those from conventionally produced natural gas, and both energy sources, on average, emit approximately half the GHG emissions of coal-powered electricity, according to a study published in the Proceedings of the National Academy of Sciences.
However, under certain circumstances, the emissions for conventional and shale gas electricity can reach levels approaching best-performing coal-fired plants, the study says.
Harmonization of Initial Estimates of Shale Gas Life Cycle Greenhouse Gas Emissions for Electric Power Generation uses a meta-analytical technique called harmonization to compare existing studies estimating life cycle GHG emissions from shale gas, conventionally produced natural gas, and coal.
The study team screened hundreds of published life cycle assessments, including dozens related to conventionally produced natural gas and shale gas. In addition, the team conducted sensitivity analysis on three important activities in the production of shale gas: well completion, well recompletion and liquids unloading. Previous research had found these activities to be significant to life cycle GHG emissions. When considering these additional factors, shale gas life cycle GHG emissions could approach the range of best-performing coal-fired generation.
Potential US chemical industry investment linked to shale gas extractions has topped $100 billion, the American Chemistry Council (ACC) reported earlier this year.