Exploring the Impact of Transition in Energy Mix on the CO2 Emissions from China’s Power Generation Sector Based on IDA and SDA

The energy transition from coal and oil to renewable energy, nuclear energy, and natural gas is a fundamental way for emission reduction of China’s power generation sector. Until now, research on the drivers of CO2 emissions from China’s power generation sector has generally evaluated the energy mix as a whole, with a lack of exploration of the decomposition of different types of energy. This paper uses both index decomposition analysis (IDA) and structural decomposition analysis (SDA) to explore the impacts of energy transition on CO2 emissions in the power generation sector during periods of 2002–2007, 2007–2012, and 2012–2017. We find that the results of IDA and SDA are almost consistent, indicating that our results are robust. During the whole study period, CO2 emissions of power generation sector increased by 2447 Mt, of which the fossil fuel structure significantly contributed 642 Mt of incremental emissions (IDA). The thermal power generation efficiency was a dominator for reducing emissions, with a total reduction of 586 Mt (IDA). Simultaneously, the impacts of renewable energy and nuclear energy on emission reduction tend to be strengthening over time, with values changing from 38 Mt and −5 Mt in 2002-2007 to −219 Mt and −83 Mt (IDA) in 2012-2017, respectively. Based on the results, we put forward some suggestions such as promoting coal-to-gas, renewable energy, and nuclear energy in power generation to cut down CO2 emissions of China’s power generation sector.