The era of high proportion of renewable energy calls for flexible power systems, Greenpeace releases report and proposes a roadmap for flexibility improvement
October 22, 2020, Beijing-The research team of the international environmental protection organization Greenpeace and Professor Yuan Jiahai released today the latest research results on China's low-carbon energy transition "Research on Multiple Improvement Paths for the Flexibility of China's Power System" (hereinafter referred to as " report"). The "Report" pointed out that China's current coal-based power system lacks flexibility and regulation, and the grid dispatching operation mode is relatively rigid, which has become a constraint on the integration and consumption of a high proportion of renewable energy. In order to achieve the carbon peak in 2030 and the national commitment of carbon neutrality in 2060, the flexibility of coal-fired power plants alone cannot meet the flexibility requirements of the power system. It is necessary to have multiple flexibility in the power system from a higher level of planning and mechanism. The deployment of natural resources will fundamentally solve the problem of the mismatch between the development of renewable energy and the flexibility of the power system.
Insufficient flexibility of the power system restricts the development of renewable energy and has become a practical problem that needs to be solved urgently. The "Report" research team calculated that between 2016 and 2018, China’s total abandonment of wind and photovoltaic power was 138.9 billion kWh, which is equivalent to the annual power generation capacity of a 30 million-kilowatt coal power plant, corresponding to about 35 billion yuan in coal-fired costs and 40 million tons. carbon dioxide emissions. Even if the implementation of compulsory policies such as fully guaranteed purchases has significantly improved the total curtailment of wind and solar power compared with before, the total curtailment of wind and solar power in 2019 is still as high as 21.5 billion kWh, which is equivalent to 4.5 million kilowatts of coal power plants a year The amount of electricity generated corresponds to about 5 billion yuan in coal-fired costs and 6 million tons of carbon dioxide emissions.
Li Danqing, Director of Greenpeace Climate and Energy Project, said: “With the non-fossil energy generating capacity accounting for 32.6% of the country’s power generation in 2019, the power system has generally faced problems such as difficulty in grid connection, consumption, and dispatch. This shows that China's coal-based power system has not yet prepared for the transition to effective access to renewable energy, and cannot adapt to the trend that the proportion of renewable energy installed capacity will increase year by year in the future."
"In fact, in order to fundamentally solve the contradiction between renewable energy and traditional coal power in the power system, we cannot completely hope for the flexible transformation of existing coal power units. Due to various reasons, the original 2.2 The goal of 100 million kilowatts of coal-fired power transformation has only been implemented so far. In the medium and long term, due to the limitations of coal-fired power’s flexible transformation technology, cost input and environmental impact, the continued increase in coal power installations will push up The minimum start-up output of conventional units has led to insufficient downward flexibility in the power system, which is not conducive to the consumption of a high proportion of renewable energy, and it is also not conducive to China’s goal of achieving carbon neutrality by 2060.” Li Danqing added. .
Professor Yuan Jiahai, the first author of the "Report", believes that to break the current rigid electricity market distribution pattern, the key is to tap the current potential of various types of flexible resources, and guide the development of "source network load storage" flexible resources with new power planning concepts. Harmony. "In some European and American countries, the proportion of flexible power sources has exceeded 30%, while my country's flexible power sources are currently only 6%. Considerable resource potential has not yet been explored and deployed."
The "Report" systematically analyzes the technical and economic characteristics of various flexible resources on the power supply side, grid side and user side in China, as well as China's current technology, market and planning flexibility development status and development space, and comprehensive consideration of flexibility Resource cost and time scale, and proposed a roadmap for improving the flexibility of China's power system.
The "Report" also selected Jilin Province, where the contradiction in the consumption of renewable energy is prominent, as an example, and simulated 6 power system operation scenarios. In the case of high penetration rate, multiple flexible resources are added, rather than relying solely on the flexibility of coal power. Through the transformation, the curtailment of wind power will be reduced by 39.9%, and the number of start-ups and shutdowns of coal power generation and the cost of start-ups and shutdowns will be reduced by 27.19% and 25% respectively.