A Combined Process Chain and Input-Output Analysis for Comparative Assessment of GHG Emissions from Electricity Generations

The electricity generation expansion planning in Thailand has considered greenhouse gas (GHG) emissions directly from the generation stage. The lower-emission power plant, i.e. natural gas, has been chosen rather than an emission-free plant. However, the choice of natural gas has been proven as a high-emission source in terms of full energy chain analysis. The combined process chain and input-output analysis is selected as a tool for comparative assessment of net GHG emissions in the study. The complexity, of energy flows and related emissions, within the economic sectors is facilitated by advantages of the input-output (I-O) model. In the I-O model, the net GHGs emission factors, directly and indirectly, are estimated by using the 1995 Thailand 180x180 input-output table, the national sectoral energy consumption statistic, and the emissions factors recommended by the Intergovernmental Panel on Climate Change (IPCC). Since the sector energy consumption is available at a higher aggregation level of economic sectors than those required by the I-O model, disaggregation of sectoral energy consumption is assumed in the study. Finally, the comparative assessment of net GHG emissions is made between the run-off-river hydroelectricity project and an independent gas-combined-cycle power plant in Thailand. Results are presented of energy intensities and net GHGs emissions from these plants.