Baseline scenario selection for sectoral climate mitigation action in power generation: A case study on the grid emission factor as intensity benchmark in Thailand

In the context of international climate policy design and negotiations, sectoral mitigation actions are discussed as options to scale up greenhouse gas mitigation and avoid dangerous climate change. One potential obstacle for crediting sectoral GHG mitigation actions is the need to agree on a credible `baseline scenario' representing the business-as-usual case of sectoral emissions. This paper explores different options for choosing indicators and technology scenarios to establish a baseline scenario for the power sector in Thailand. We argue that absolute technology diffusion targets are not suitable for calculating baseline emissions, since it is not clear whether and how Thailand will achieve its ambitious renewable energy targets. We further show that setting a baseline scenario for the emission intensity per unit of electricity - instead of absolute emissions - circumvents the significant uncertainty resulting from projections for power demand growth. However, the methodology currently used by the Thai government to calculate the emission intensity would need to be reformed to include emissions from imported electricity to ensure effective regional mitigation and avoid carbon leakage. Moreover, transparency and data collection issues need to be addressed to facilitate measurement, reporting and verification of emission reductions beyond the business-as-usual scenario.