Comprehensive sustainabilityassessment of china's electric energy system based on emergy analysis

The green and healthy development of the energy system is related to the sustainable development of economic activities. The quantitative sustainable evaluation of the energy system is the guiding principle of the current energy structure transformation. Therefore, this paper adopts the emergy analysis theory, based on the development forecast of the power supply structure in different stages of China, firstly, the environmental loading ratio, emergy yield ratio, emergy sustainability index and emergy investment ratio are used to carry out the five common power generation modes, including wind power, photovoltaic power, coal power, gas power and hydropower, and it is concluded that under the current conditions, the emergy sustainability index of wind energy is optimal. Thirdly, considering the four dimensions of power generation efficiency, installed cost, full life cycle cost, and emergy sustainability index, a comprehensive evaluation system of China's electric energy system based on emergy analysis is proposed, which quantifies the development trend of the structure has shifted from coal-based to diversified with clean energy and scenery from 2020 to 2050. The comprehensive evaluation result has increased from 0.2 to 1. The comprehensive evaluation results continue to increase with the year, indicating that China's electric energy structure is more optimized, showing a higher vigor of sustainable development.