In September 2020, China announced to the world the goal of carbon peak carbon neutrality. In March 2021, the Ninth Meeting of the Financial and Economic Commission of the CPC Central Committee made it clear that it would "build a new power system with new energy as the main body". Here, talk about how to guarantee power supply under the condition of carbon peak:
1. Characteristics and challenges of power supply protection under carbon peak conditions
By the end of 2020, China's electricity consumption will reach 7.5 trillion kilowatt hours. The total generating capacity is 7.6 trillion KWH, of which 1.36 trillion KWH is generated by hydropower, accounting for 18%, 5.17 trillion KWH is generated by thermal power, accounting for 68%, 366.2 billion KWH is generated by nuclear power, accounting for 4.7%, 466.5 billion KWH is generated by wind power, accounting for 6%, and 261.1 billion KWH is generated by solar power, accounting for 3.3%. The installed power generation capacity reached 2.2 billion kW, of which, hydropower was 370 million kW, accounting for 16.8 percent, thermal power 1.24 billion kW, accounting for 56 percent, nuclear power 49.89 million KW, accounting for 2.3 percent, wind power 280 million kW, accounting for 12.7 percent, and solar power 250 million kW, accounting for 11.4 percent. Electricity from the west to the east will reach 270 million kilowatts. Clean energy generation accounted for 32% of the total power generation and installed power generation accounted for 44% of the total installed power generation. Scenic power generation accounted for 9.3% of the total power generation, and installed power generation accounted for 24.1% of the total installed power generation.
Related studies have shown that long-term power demand will continue to grow in our country, the whole society power consumption in 2030 is expected to reach 11.5 trillion KWH, electricity needs 11.8 trillion kilowatt hour above, "on the basis of the 'difference' power basic balance between supply and demand, combined with all kinds of power supply the paper studies the development potential of medium and long-term national will there is a big power gap". This raises the question, in the process of implementing the "3060" goal, how to scientifically combine the characteristics of the new power system with new energy as the main body to ensure the power supply?
The author believes that the following characteristics and challenges of the new power system with new energy as the main body have a great impact on ensuring the safe supply of electricity:
Is a new energy as main power supply, due to the intermittent characteristics, makes the guarantee of main power supply output is low, effective use of hours is not high, affected by the climate conditions, run output strong randomicity, affected by the distributed power, the capacity of high dispersion, can act as the principal role of total power, but bear the instant or balance during the period of the main body role of electricity co., LTD., Conventional power supply, large power grid and energy storage facilities must be equipped to regulate and support;
Second, wind power and photovoltaic power supply are currently connected to the AC system in the form of inverters, so that the main power supply can prevent the power grid instability when resisting large-scale power loss or serious power grid failure, and play a very limited role in supporting the power grid frequency and voltage.
Third, with the increase of the proportion of new energy sources, China's power grid will gradually take shape to optimize the use of new energy power as the focus, to support the block power grid of the comprehensive energy system as the unit, urban power grid and local power grid base as the basis, and the load-intensive receiving power grid as the center of gravity. As a new mode of transmission and switching platform with multiple voltage levels, ac and DC co-existing and layered zoning, ultra-high voltage network needs to innovate strategies, strategies and technical measures for safe and economic operation and management of power system.
Fourth, the application of a large number of electric power electronic equipment has brought new changes to the characteristics of power grid. The traditional transient stability is faced with new problems brought by insufficient moment of inertia, and the power grid stability problem caused by new inducements also needs to be studied. The simulation accuracy and analysis depth of power system need to be greatly upgraded.
Fifth, new energy generation, energy storage, electric vehicles, etc. are integrated into the power grid in large numbers. The information infrastructure of power grid digitization and coordinated control of source network load and storage, such as the scale of monitoring points, monitoring mode, information processing and exchange, and network security, need to be comprehensively upgraded.
Sixth, some key technologies supporting the construction of new power systems, such as energy storage safety, hydrogen production and utilization, fuel cells, carbon capture technology, are still in the research and development stage, with many uncertainties.
These characteristics and challenges will have a significant impact on ensuring power supply, which needs to be quantified through detailed production simulations and safety and stability calculations. Here is an example to illustrate briefly.
Take the electricity balance in 2030. Assuming that the annual electricity generation in 2030 will be 11.8 trillion KWH, take 9 or 10 PM on August 10, 2030 as an example. At this time, the nationwide full-bore load is expected to be 1.8 billion to 2 billion kW (the average annual growth rate is about 1 percentage point higher than the power generation growth rate), without considering the power grid blockage. The unit's peak load regulating capacity, generation characteristics and load tracking speed are not considered. This time point is the typical time point of heavy load in summer, and also the typical time point of seasonal trough of wind power and photovoltaic daily trough. At this point, the photovoltaic power output is zero, according to statistics, the existing wind seasonal trough one 9 of the efforts for years large output, is the wind power and solar power (power 1.2 billion kw or more) of the total output of about 075 million kilowatts, thermal power, hydropower and nuclear power output standby rate was 20%, load is calculated at 1.9 billion kw, The system needs to provide 409 gw of gas-fired power generation and/or energy storage. The total gas-fired generation and/or storage capacity may need to reach more than 500 gw if grid congestion, thermal peak-scaling capacity and load-tracking speed are taken into account. This typical time point is one of the shortcomings of the power balance barrel, which also includes the low or zero output of photovoltaic power generation for many consecutive days in the plum rain season in southern China, as well as extreme weather scenarios in early 2021. The balance of power quantity in these scenarios is a challenge that the new power system with new energy as the main body must face in ensuring power supply. To ensure power supply under the condition of "dual carbon", sufficient supporting power supply, energy storage capacity and power grid exchange capacity are required to meet the requirements of "dual carbon".
Second, the consideration of power supply protection measures under the condition of carbon peak
1. Ensure the connection between carbon peak and power supply guarantee scheme under carbon neutral conditions
Carbon peak and carbon neutrality are the links between the preceding and the following. The fourteenth Five-year period is the critical period and window period of carbon peak, and the peak period is the critical period and window period of carbon neutralization. There is a global consensus that the power industry is a key sector to achieve carbon neutrality. The power supply planning scheme under the condition of carbon peak should not only solve the problem of power supply before 2030, but also provide a solution to deal with various uncertainties for the carbon neutral path optimization of the power industry in 2060. To improve the level of electrification is the world recognized as the main measure to promote carbon emission reduction, under the condition of ensuring the diversified needs of China's socialist modernization construction, optimize the selection of carbon peak time in the power industry, adhere to the principle of seeking truth from facts, seize the window of opportunity, scientific planning and policy, and effectively implement the "3060" target.
2. Make clear the standard requirements of power supply insurance
From the research results of public, during the period of "difference", may have a power shortage situation in parts of our country, the electrical supply to the power system to cope with extreme weather is difficult, at the same time, the high proportion of new energy power generation and power grid of high power electronic, moment of inertia of yet from material to solve the problem of insufficient, has brought power grid security risk. In this context, it is necessary to clarify the sufficiency and reliability standards of power supply, and different standards will correspond to different power supply measures.
3. Speed up the development, appropriately advance, rational distribution of new energy power generation
By the end of 2020, China's total installed wind and solar power capacity reached 530 million kw. To achieve the goal of 2030, need to combine near and far, under the premise of economic acceptability, appropriate advance construction of new energy units, in order to improve the overall support of new energy units output. Speed up the construction of new energy bases in western China, implement complementary energy sources at both ends, pay equal attention to local utilization and delivery, speed up the construction of a comprehensive energy system with block power grids as the core, and give full play to the technological advantages of distributed new energy generation. We will intensify the development of offshore wind power, optimize the distribution of wind power in China, and implement the industrialization and large-scale development of power generation, hydrogen production and hydrogen supply. Accelerate the technological progress and construction scale of solar thermal power generation, improve the support capacity and regulation capacity of solar power generation.
4. Technology upgrading, efficient utilization and scientific utilization of coal-fired power generation
There is much debate at present about whether to build new coal-fired generating units. In its global carbon neutral path study, the INTERNATIONAL Energy Agency proposed that "no new coal power plants without emissions reductions, no new coal mines or expansions will be approved from 2021" and "no fossil fuel boilers will be sold in 2025". In such an international environment, how to give full play to the role of coal power in the process of China's transition from coal-fired power system to new energy system is a problem that must be faced in ensuring power supply and promoting the implementation of China's carbon neutrality goal and path optimization under the condition of carbon peak. Whether to build a new coal power unit depends on whether the support power supply in the power grid can meet the requirements. From the current point of view, under the condition of carbon peak, the balance of electricity is not the main contradiction, but the key is the intra-day, medium and short term and local power imbalance caused by the intra-day and seasonal fluctuations of new energy units and extreme weather. If is really necessary, therefore, a new coal unit, can consider to order control based on carbon dioxide emissions in the industry, from the perspective of power balance support ability, building new coal unit scale, at the same time, the new coal unit as possible considering carbon capture technology pilot demonstration of the application, and electricity price policy support. Under the condition of carbon peak, the technical upgrading and transformation of existing coal power units is a difficult task, which is also an important guarantee of power supply. First, it is necessary to speed up the flexibility transformation of coal power units. At present, the peak load adjustment depth of coal power units is far from meeting the peak load adjustment requirements of power grid. It is necessary to continuously improve the depth peak load adjustment capacity of coal power units through various technical routes and corresponding electricity price policies. Second, under the premise of mature technology, begin to layout coal power units to add carbon capture facilities renovation; Third, in order to implement the "3060" target, coal power units will be phased out of operation, and overall planning should be made as soon as possible. In the last century, foreign countries have some mature practices in this respect, including the transformation of coal power unit into synchronous camera, gas unit and storage for emergency use and so on. In particular, it is very important for the new power system with new energy as the main body to transform the coal-fired generating set into the adjustable camera, so China should put forward the plan for the transformation of the retired coal-fired generating set according to the new situation and new requirements.
5. Clear positioning, moderate development, and give full play to the role of gas power generation
Gas power generation has the characteristics of fast regulation speed, large peak modulation range and low carbon dioxide emissions. From the international point of view, on the one hand, some countries such as the United States have a greater advantage in the new energy absorption capacity of the grid than China because of the large proportion of natural gas power generation to power capacity. On the other hand, the International Energy Agency, in its global Carbon neutral path study, proposed that no new oil and gas fields be approved from 2021; The U.S. state of Washington proposed a zero-carbon plan for buildings earlier this year, requiring natural gas to be completely removed from civilian use. In view of China's reality, before energy storage cannot fully meet the requirement of power balance in all time, all weather and all regions with new energy, it is an important measure to ensure power supply to moderately develop gas-fired power generation, improve the supporting capacity of power system and control carbon dioxide emissions. It needs to be further clarified that gas power generation is mainly used as support power supply for auxiliary services. Gas power generation models should be optimized and their technical economy should meet the requirements of their role in the power grid. Second, for the areas covered by natural gas pipelines, comprehensive energy system construction can be considered, and small-scale multi-cogeneration gas turbines can be moderately constructed as emergency backup power for important users. Third, the construction of gas-fired power generation should consider the timely installation of carbon capture facilities; Fourth, the scale of gas-fired power generation should be optimized and determined in accordance with the principle of active and moderate development on the premise of meeting the standards of power adequacy and reliability and being conducive to orderly control of China's total carbon dioxide emissions.
6. Create conditions to ensure safety and actively develop nuclear power
The development of nuclear power is an important measure in the process of reducing emissions in Europe. According to the specific situation of China's power supply structure, under the premise of ensuring the safety of nuclear power, actively developing nuclear power is an important measure to achieve carbon peak, carbon neutrality and solve the problem of power balance. Nuclear power needs to consider peak regulation in the new power system. Nuclear power is capable of peak regulation, and France has good practical operation experience in this aspect.
7. Adopt multiple measures to solve problems and improve the flexibility and reliability of power grid
In the face of new energy as the main body of the new challenges brought about by the power system, the first thing to solve the problem of electric network flexibility, moment of inertia of shortage of power grid disturbance caused by the large power grid stability and power electronic devices and related facilities parameter configuration coordinate subsynchronous resonance caused by such network security issues, at the same time, according to the characteristics of the new optimization power grid security defense strategy. Will comprehensively carding grid congestion, according to the actual needs of the new power system expand the channel capacity, to ensure meet the electricity transmission grid and to meet the requirements of local power exchange between grids, cross-regional, time zone, inter-basin peak, accident support benefit, to support the premise of power matching and energy storage capacity, Ensure the power balance and reliability requirements of the whole grid, all time and all weather. From the power grid structure, equivalent mass moment of inertia of the new type of power system, the moment of inertia of the lack of new solutions, on the basis of the existing technology, to ensure that by the end of the power grid has enough ability of dynamic power and reactive power support synchronous condenser transformation construction, layout of emergency low voltage load system, Control the occurrence of virtual synchronizer with small capacity in a large system. Accelerate the research on the mechanism and systematic countermeasures of sub-synchronous stability caused by high proportion of power electronic equipment. It is necessary to attach importance to the construction of user integrated energy system, utilize the advantages of energy storage, distributed power supply, demand side response and information technology, and enrich the concept of user reliability-oriented security defense.
8. Promote digital and intelligent power grid with overall planning and focus on the basics
In the process of power system transformation, the power information application system and its infrastructure should be planned and rationally distributed according to the requirements of coordinated control of new energy generation, energy storage and source network load and storage. It is necessary to expand the functions and information perception and application of upgrade and coordination dispatching automation, plant and station automation, distribution automation, demand side response, power market, energy storage management, safety and stability control and other systems, strengthen information security management, and apply advanced information technology to ensure that the system is reasonable, efficient, accurate and reliable.
9. Accelerate research and development, secure application, and strive to solve the safety technical problems of energy storage
The development and application of energy storage technology is critical to the realization of the "dual carbon" goal. The current scale of energy storage is far from meeting the demand. First, we should further explore possible pumped storage power station sites and develop pumped storage to the limit. Second, to accelerate the research and development of chemical and other ways of energy storage technology, and strive to form a larger scale, the current first to solve the safety problem of lithium battery energy storage; Third, the construction of energy storage should be rationally distributed, and the necessary energy storage facilities should be separately arranged on the power supply, power grid and user side. Special attention should be paid to the reasonable planning and layout of the user side energy storage, so that it can not only become the effective capacity of the system power balance, but also become the user's emergency power supply, and improve the reliability of power supply. At the same time, a unified, coordinated and controlled hierarchical distributed energy storage system should be considered to ensure that the energy storage facilities of the specified scale can be controlled and become an effective capacity to participate in the balance of electric power quantity.
10. Intensify research and development efforts, accelerate pilot demonstration and application, and focus on key technologies such as green hydrogen and carbon capture and utilization
Green hydrogen and carbon capture technologies play an important role in achieving carbon neutrality. The research and innovation of hydrogen production, transportation, utilization and business model should be accelerated, and the pilot demonstration and application of various scenarios should be accelerated to form an industrial chain of commercial application as soon as possible. Efforts should be made to research and develop carbon capture, utilization and storage technologies, improve capture efficiency, reduce energy consumption and cost, accelerate pilot and demonstration applications, and gradually realize industrialization and commercial application. At the same time, research and development of forward-looking technologies such as hydrogen power generation, small-scale civil nuclear power and nuclear fusion should be done well.
Three and two suggestions
1. Set up the peak carbon neutrality National Laboratory for energy and power, and organize special forces to carry out research and scientific research on issues related to "double carbon"
The energy and power problems involved in carbon peak carbon neutralization are systematic, cross-professional, practical and forward-looking. At present, the research method is limited by the scope of the research subject and the research depth is limited by the time limit of the research project, which is characterized by fragmentation and short-term. The juguo system has made great achievements in major innovation projects, but has yet to find a good mechanism for basic research and major systematic technology research and development. At present, although there are some state-level laboratories in the field of energy and electric power, their specialized fields are narrow. Argonne Laboratory is a national laboratory under the supervision of a third party under the Department of Energy of the United States of America. It plays a very important role in energy technology innovation and other aspects. Currently, important innovative research areas include energy and environment. Advice to "double carbon" energy power related issues and technology research and development as an opportunity to state energy power for the construction of the national laboratory, laboratory of key task is to research and development organization continued research in our country to realize the objective of "double carbon" systematic, forward-looking, fundamental, conditionality, critical and interdisciplinary science and technology issues and major power energy strategy. This national laboratory can be jointly managed by the national energy department and the department in charge of science and technology. If necessary, it can also be assisted by a third party organization with high authority, wide professional scope, strong neutrality and familiarity with science and technology work to study the specific management mode, and the combination of real and virtual can be adopted in the initial stage.
2. Research and build an energy and electric power development deduction system to improve the quantitative analysis level of major issues in energy and electric power development and provide support for scientific decision-making
The energy and electric power system is a complex system with multiple influencing factors and time-varying domains. It is a mature practice abroad to use deductive technology to study complex system problems, even military problems. The United States has the world's leading inference technology and inference system. Modern inference technology has been integrated into computer simulation, operations research, model thinking, etc. In recent years, it is even integrated into the new generation of information technology such as big data and artificial intelligence. The simulation methods and systems of China's energy and electric power system have been widely adopted, but at present these systems are mostly limited to a professional field. Based on this, the deductive technology and concept are introduced to establish the deductive system of energy and electric power development in the mode of digital twin. In order to implement the "double carbon" target requirements, It is of great significance to study the development path and measures of optimizing energy and electric power system under the condition of various uncertain factors, and to provide technical support for policy.
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