Comprehensive Sustainability Evaluation of China’s Power System Based on Emergy Analysis

The green development of the power energy systems is related to the sustainable development of economic activities. Therefore, a quantitative sustainability evaluation of a power energy system is the key task of the energy mix transition evaluation under the "carbon neutral". In order to quantitatively analyze the energy, economic and environmental benefits of different power technologies, this study first adopted the emergy analysis theory to analyze the emergy sustainability index of the five power generation modes of photovoltaic power, wind power, hydropower, gas and coal power, and it was found that under the technical and economic level, wind power has the best emergy sustainability index. Second, comprehensively considering the three dimensional indicators of emergy sustainability index, power generation efficiency, and full life cycle cost, the comprehensive evaluation system of the sustainable development of China’s power energy system was constructed based on the gray correlation analysis method, and China’s power energy structure from 2020–2050 for coal-based to clean energy production were quantitatively analyzed. The emergy sustainability method proposed in this study could provide a scientific reference for the quantitative research and determination of regional energy transition.