CO2 emissions from electricity generation in China during 1997–2040: The roles of energy transition and thermal power generation efficiency

Highlights: • Two-stage LMDI was used to examine the drivers of electricity CO₂ emissions. • The contribution of renewables to emissions decline was getting stronger and stronger. • We studied the impacts of regional convergence and electricity mix on future emissions. • The regional convergence can help the persistence of CO₂ emissions reduction. • Ambitious targets for low-carbon energies can help the rapid decarbonization. CO₂ emissions from electricity generation (CEE) in China increased from 935 Mt to 3511 Mt during the period 1997–2017, ignoring a slight decline from 2013 to 2015. To identify what resulted in this pattern and how to peak China's CEE in the future, this study first quantitatively evaluated the drivers of CEE. Then, considering both the energy transition and thermal power generation efficiency (TPGE) could make sense in CEE reduction, based on historical data from China's 30 provinces during 1997–2017, we established twelve scenarios, which were hybrids of four electricity mix scenarios (refer to International Energy Agency (IEA) and China National Renewable Energy Centre (CNRE)) and three TPGE scenarios (business-as-usual (BAU), median scenario, and best-available-technology (BAT)), to explore the impacts of energy transition and regional convergence in TPGE on CEE until 2040. The BAU scenario assumes the TPGE in all provinces develops as historical trends, while the median scenario and BAT scenario represent a form of weak and strong regional convergence in TPGE across provinces, respectively. The decomposition results showed that TPGE was a dominator in emissions reduction, followed by the share of renewables in electricity generation. The scenario analysis indicated that when the electricity mix changes with IEA's Current Policies scenario, the decline in CEE will be not persistent after 2017 unless a strong regional convergence in TPGE occurs. Moreover, under BAT scenario, with any case of electricity mix the CEE in 2040 is 31–54% lower than that under BAU scenario. The results also showed that more ambitious targets for developing low-carbon technologies could help the rapid decarbonization of China's electricity sector.