Transformation Pathways of China's Power Sector in the Context of "Carbon Peaking and Carbon Neutrality"

. To achieve the "carbon peak" and "carbon neutrality" goals, the power industry is the main battlefield and main force. Compared with the long carbon reduction path after natural peak in major European and American countries, the carbon peak, plateau period, and transformation path under the "dual carbon" goal in China will be completely different. This article establishes a multi-scenario analysis framework for the transformation path of the power industry under the "dual carbon" goal, and constructs three major scenarios. It analyses the low-carbon transformation path of power system including power source structure and carbon emissions under different scenarios and proposes policy recommendations.


1.Introduction
China proposes to actively and steadily promote the "carbon peaking and carbon neutrality", and accelerates the planning and construction of new energy systems. Electricity is an important material basis for economic and social development, and is the main force to achieve "carbon peaking and carbon neutrality". Building a new power system is the core of the planning and construction of new energy systems. [1][2][3] Energy activities are the main source of CO2 emissions in China. Currently, energy activities contribute about 87% of all CO2 emissions and more than 70% of all GHG emissions. Given the high proportions of coal and coal power in China, the key to the low-carbon transition of energy power lies in the clean utilization of coal. [4] "Carbon peaking and carbon neutrality" is a broad and profound systematic change both economically and socially. The transformation pathways of energy power in the context of "carbon peaking and carbon neutrality" involve various sectors of economic and social development, such as industry, transportation, construction and agriculture. [5][6] They should be integrated and planned systematically with the transformation pathways of other sectors to become an overall optimal pathway of carbon reduction for the whole society. [7][8][9] The demand side needs to reduce energy consumption intensity and carbon emission intensity through industrial restructuring and upgrading of energy use and manufacturing processes. The supply side needs to speed up the development of non-fossil energy, build a new power system that adapts to the increasing proportion of new energy, and take on a sustainable development path that places equal emphasis on safety, stable supply, clean energy, and low carbon emissions. [10] Based on the model independently developed by the State Grid Energy Research Institute, this paper studies the transformation path and emission reduction path of China's power industry from 2020 to 2060 under the "dual carbon" goal, and proposes relevant policy recommendations. Fig. 1 is the overall design of this research.

2.Research Methodology and Model Tools
The China Energy-Economy-Environment System Optimization Model and GESP, a multi-regional power supply and power flow optimization system, developed independently by the State Grid Energy and Power Planning Laboratory, are applied to systematically analyze the transformation pathways of energy power, emission pathways and the impact of key uncertainties on the pathways in different scenarios. Fig.2 is the basic layout and principle of GESP.
Fundamentals of GESP: Based on the principle of minimizing the total cost of the power system, new energy power generation, energy storage, CCUS and hydrogen energy models are incorporated into traditional power planning to realize the optimal planning of power supply investment decision-making, peak-regulating power allocation and cross-regional transmission expansion that include new energy, and to achieve multi-region coordinated planning and integrated optimization by combining new energy power generation with traditional power supply.

3.Scenario Design and Critical Boundary Conditions
Energy power transformation should be integrated into the whole process of economic and social development, and different economic development patterns correspond to different industrial structures and the optimal transformation pathways of energy power in the context of "carbon peaking and carbon neutrality" for the whole society under corresponding conditions. Toward the goal of realizing carbon neutrality in the whole society by 2060, this research develops three scenarios: steady industrial adjustment -deep energy structural adjustment, moderate industrial adjustment -moderate energy structural adjustment, and deep industrial upgrading -steady energy structural adjustment (hereinafter referred to as steady industrial adjustment scenario, baseline scenario, and deep industrial upgrading scenario).
Baseline Scenario: The industrial structure is optimized and adjusted, and the GDP per capita will reach the level of moderately developed countries by 2035.
Steady Industrial Adjustment Scenario: The industrial structure maintains the current evolutionary trend, with manufacturing taking up a relatively high share.
Deep Industrial Upgrading Scenario: The share of the tertiary industry increases significantly and reaches the level in the most developed countries.

4.Power Sector Transformation Pathway
The future electricity demand in China will be mainly influenced by macroeconomic growth, industrial structural changes, the development of high energyconsuming industries, electric energy substitution and hydrogen production by electrolysis. In the near to medium term, the electricity demand in China has great growth potential and will grow fast. [11] As shown in Fig.3 ,the electricity consumption in the whole society is expected to reach about 11.90 trillion kWh by 2030, an increase of 53% compared with 2020, and the average annual growth rate is about 4.3%.Electricity demand is expected to enter a period of growth with saturation after 2040-2050. In 2050 and 2060, the electricity demand in the whole society will reach about 15.10 trillion kWh and 15.70 trillion kWh, and the electricity demand growth will be saturated. Different energy efficiency levels in different scenarios and the extent to which the pressure of emission reduction is transferred in each industry will deeply influence the electricity demand growth pattern. By 2060, the electricity demand is expected to be increased by about 10% in the steady industrial adjustment scenario and decreased by about 8% in the deep industrial upgrading scenario.  China will go through continuous optimization of power supply structure. nearly 80% of the incremental installed power supply capacity and 70% of incremental power generation before 2030 will be contributed by nonfossil energy. By 2030, the installed capacity and power generation from non-fossil energy will be accounting for 60% and 50% of the total; by 2060, it will reach above 90% .
China has abundant potential in new energy generation resources, with technically exploitable reserves of more than 3.5 billion and 5 billion kW, respectively. West China and North China: actively promote the development of large-scale wind and PV power bases in deserts, Gobi, and wilderness.East China and Central China: develop distributed PV power, decentralized wind power and offshore wind power in East China and Central China according to local conditions.By 2060, the installed wind power capacity will reach 2 billion kW, including 300 million kW of offshore wind power; the installed solar power capacity will reach 2.5 billion kW, including 250 million kW of solar thermal power. [12] Actively promote hydropower development. Accelerate the development of resources at high-quality hydropower sites in Southwest China before 2030; focus on promoting hydropower development in Tibet after 2030; basically complete the development of conventional hydropower resources by 2040; push the installed capacity to about 500 million kW in 2060.
Pursue orderly development of nuclear power while safety is ensured. Put an average of 6-8 units into operation each year before 2030, and push the installed nuclear power capacity to 120 million kW in 2030. With the completion of the resource development at coastal sites, development of inland nuclear power should be started when appropriate after 2030 to push the installed capacity to 400 million kW or more in 2060.
Accelerate the development of pumped storage and new energy storage. Vigorously develop pumped storage and accelerate the development of new energy storage technologies in the near to medium term to push the total installed energy storage capacity to 220 million kW in 2030; accelerate the development of new energy storage in the medium to long term, with the total installed capacity expected to reach 800 million kW or more in 2060.

5.Carbon Emission Reduction Pathways of Energy Power Sector
Carbon emission reduction pathways can be split into four periods as shown in Fig. 4: Rising to Peak Period (2020-2030): The plateau period of carbon emission peaking will arrive by 2030. Steady Carbon Reduction Period (2030-2040): China's carbon emissions will remain at the peak plateau stage during 2030-2035. After 2035, with the rapid development of terminal electrification and clean energy, China's carbon emissions will begin to steadily decline. Accelerating Carbon Reduction Period (2040-2050): After 2045, as the power supply mix is inclined to clean energy faster, China's carbon emissions will decline more rapidly. Neutrality Period (2050-2060): China's carbon emission reduction is further accelerated, and considering the implementation of measures such as natural carbon sinks and CCUS, net zero emissions will be realized in the economy and society..

6.Conclusion
Coping with climate change is an international consensus that calls for all parties to work together. The energy power transformation in China is a highly complex issue that needs to integrate multidisciplinary, multi-sectoral and multi-territorial efforts under industry-universityresearch institute collaboration. The power sector is the most important contributor of carbon emission growth in the rising to peak period as it can share the emission reduction pressure from the end-use energy consuming sectors through electric energy substitution, and it is expected to enter the peak plateau period around 2030. From the perspective of the whole society, with safety, economy and low-carbon goals coordinated, it is a better solution to help the whole society reach carbon peaking steadily by allowing the late carbon peaking of the power sector.