Scenario Planning And Environmental Benefits Study For China’s Future Energy System With High Proportions Of Renewable Energy

To avoid extreme climate disasters,the IPCC has proposed that countries around the world need to achieve carbon neutrality by 2050 in order to reach the 1.5°C target.As one of the main measures to reduce carbon emission,the large-scale use of renewable energy will be an irreversible trend in the transformation of China’s future energy system.Meanwhile,due to the instability,large-scale renewable energy utilization will bring challenges to grid security.Therefore,the feasibility of high-proportion renewable energy system and its social and environmental benefit analysis are of great significance to China’s future energy development.Currently,most of the related studies focus on the analysis of high-proportion renewable energy systems in Europe and the United States and other countries,with fewer studies considering resource potential and energy load in China.To fill this gap,this study analyzes the technical and economic feasibility and the benefits of greenhouse gas and air pollutant emission reduction of high-proportion renewable energy systems.In this paper,three scenarios are analyzed for 60%,80%and 100%renewable energy in China in 2050.Firstly,in the 100%renewable energy system,the energy demand after full electrification of China’s energy end-use in 2050 is simulated and calculated.Then the required installed capacity of different types of renewable power generation is simulated according to the amount of renewable energy available in China.Then the hourly energy demand and supply data are put into an energy supply and demand matching model built in Python to simulate the feasible required installed capacity and energy storage capacity according to the principle of no load loss.Then,the cost of electricity supply,reduced air pollution and greenhouse gas emissions of the target scenario are calculated based on the simulation results.Furthermore,the energy balance,cost of power supply,and environmental benefits of the 80%and 60%renewable energy systems are analyzed with similar methods as in the 100%renewable energy scenario analysis.The results show that all three energy scenarios are feasible,though it is difficult to achieve a100%renewable energy system,in which wind power and photovoltaic need to be developed to 95%of the likely-developable potential.Besides,in 100%renewable energy system,1789 TWh of underground thermal storage is required.The cost of supplying electricity exceeds the cost of supplying electricity in the business-as-usual scenario（0.3402CNY/kWh）by 29.6%.Achieving 100%renewable energy could reduce air pollution premature deaths in China by 700,626 people in 2050,with associated cost reductions of more than 5.25E+13 CNY.Furthermore,9.04E+09 t CO₂e of greenhouse gas emissions can be reduced in 2050,which approximates the total emissions reductions of 286 600 MW thermal power plant carbon capture and storage projects over the next 30 years.The 80%renewable energy scenario requires 77%and 75%of the likely-developable potential for wind and central PV,respectively.Installed capcacity of wind power needs to grow at an average annual rate of about 12.45%from 2019-2050（the average growth rate of installed wind power capacity in China is 12.58%from 2015-2019）.The required underground thermal storage capacity and phase change material storage capacity are 1,379 TWh and 129TWh,respectively.The power supply cost is 0.4235 CNY/k Wh.Over 3.83E+13 CNY of air pollution costs and 6.45E+09 t CO₂e greenhouse gas emissions can be reduced.For achieving the 60%renewable energy system,an average annual growth rate of 11.42%for wind power to 2050 is required,with the deployment of 871.2 TWh and 97.5 TWh of underground thermal and phase change storage facilities,respectively.This could reduce the cost of air pollution by more than 2.08E+13 CNY and reduce 3.42E+09 t CO₂e greenhouse gases,an emission reduction of 37.9%compared to business-as-usual scenario.Three scenarios can all achieve zero load loss,in which the 100%renewable energy system with the highest power supply cost requires an average annual growth rate of wind power exceeding that from 2015 to 2019.Yet its environmental benefits are the greatest.In summary,this study analyzes the technical feasibility of high-proportion renewable energy systems in China and quantifies the energy supply costs and environmental benefits.Future research should emphasize the technical research and application of energy storage facilities to make up for the shortcomings to cope with the fluctuations and risks associated with the large-scale renewable energy grid integration in the transition to a low-carbon energy system.