Deepening the reform of the power system and building a new type of power system with new energy as the main body are major decisions and arrangements made by the CPC Central Committee based on ensuring national energy security, realizing sustainable development, and promoting the implementation of carbon peak and carbon neutral goals. They provide important strategic guidance for the development of the energy industry and related industries in the new era. It will help accelerate China's efforts to build a clean, low-carbon, safe and efficient modern energy system, and promote green economic and social transformation and high-quality development.
First, the historical opportunity of new energy development and the challenge of power system under the new situation
At present, China is in the later stage of industrialization, and its economy is highly dependent on energy. China's energy consumption is dominated by fossil energy, and fossil energy accounts for 84% of primary energy in 2020. Under the goal of carbon peak and carbon neutrality, China's energy structure will be adjusted at a faster pace, and the characteristics of clean and low-carbon development will become more prominent.
1. Carbon peak and carbon neutral targets promote the transformation of new energy into "main energy"
With the development of economic and social transformation and the continuous improvement of energy efficiency, the total energy consumption will gradually decline after the peak of carbon emissions, but the total electricity consumption has been on the rise, and is expected to increase from 7.5 trillion KWH in 2020 to 15-18 trillion KWH in 2060.
New energy will embrace the historical opportunity of leapfrog development, become the main force of electric energy increment, and realize the transformation from "supplementary energy" to "main energy". It is estimated that by 2030, the installed capacity of wind power and photovoltaic will exceed 1.6 billion kilowatts, accounting for about 47 percent of the total installed capacity, up from 24 percent in 2020. The power generation capacity of new energy will reach 3.5 trillion kilowatt hours, accounting for 30 percent of the total installed capacity, up from 13 percent in 2020.
After 2030, hydropower, nuclear power and other traditional non-fossil energy sources will be limited by resources and site constraints, and the construction of new energy sources will be further accelerated. It is expected that by 2060, the installed capacity of wind power and photovoltaic will exceed 5 billion kilowatts, accounting for more than 80% of the total installed capacity, and the capacity of new energy will exceed 9.6 trillion kilowatt hours, accounting for more than 60% of the total installed capacity, becoming an important support for the power system.
(2) Challenges faced by new power systems
New energy has typical intermittent characteristics and strong random fluctuation of output. The new load represented by electric vehicles has obvious peak characteristics, and the ratio of maximum load to average load continues to increase. The randomness of the generation side and the increase of peak-valley difference on the load side will have a great impact on the traditional power system. In order to realize the vision goal of building a new power system with new energy as the main body, we also need to deal with the following problems:
First, the reliable capacity of the power system is insufficient. Wind power and photovoltaic have low reliability due to their output characteristics. According to the study, by 2030, under the condition of relatively uniform distribution across the country, the installed capacity of new energy will exceed 1 billion kilowatts, and the output will be less than 10% of the installed capacity for more than 30 days every year, and the confidence capacity is only 100 million kilowatts.
Assumes that the peak load of about 1.8 billion kilowatts, water and electricity installed 500 million kw, and reliable capacity of about 350 million kilowatts, installed 300 million kw, and reliable capacity of about 300 million kilowatts, wind power, photovoltaic and reliable capacity by 100 million kilowatts, other renewable power supply reliable capacity by 050 million kilowatts for column, consider interruptible load and electric cars such as the adjustable capacity of about 500 million kilowatts, That leaves a reliable capacity gap of about 500 gigawatts, which means there is still a demand for stable power (thermal power).
Second, the traditional large power grid is difficult to meet the future demand for power transmission. For a long time, China's energy resources and load have been in reverse distribution, and large power grid is an important way to connect resource areas such as the three north regions and load areas in the middle and east. But with the economic and social development, the demand for electricity is increasing day by day. It is estimated that by 2030, the total social electricity consumption of Guangdong, Fujian, Zhejiang, Jiangsu and Shandong provinces alone will reach 3 trillion KWH, and may reach 5 trillion KWH in the future.
If the vast majority of the transmission is from the three North regions, the power transmission scale will reach 4 trillion KWH according to 80% calculation, which requires the construction of about 100 UHV transmission channels, and each UHV is not restricted by the electromagnetic ring network, and the full power operation all year round, which will undoubtedly be difficult to achieve.
Third, the power system rotational inertia and long period adjustment ability is insufficient. Photovoltaic power generation uses the photoelectric effect of semiconductors to convert light energy into electrical energy. There is no rotational inertia, and the rotational inertia of wind power generation is also seriously insufficient. Therefore, when a large number of new energy units replace conventional power sources in the power system, the frequency regulation ability of the system will decrease significantly. On the other hand, current electrochemical energy storage and other technologies can only solve the short-term regulation problem of power system, and due to the constraints of cost and other factors, there are still great obstacles for monthly regulation and quarterly regulation.
However, it is difficult for hydrogen energy, CCUS and other technologies to make breakthrough and achieve large-scale application in a certain period of time. When extreme weather conditions occur in local areas, the power system with high proportion and large-scale new energy will face the challenge of insufficient long-term regulation ability.
Second, new power system connotation, characteristics and key technology prospects
Taking new energy as the main body, the new power system connects all links of supply and demand of clean energy, which is conducive to reflecting the multiple values of clean electricity, promoting the low-carbon transformation of economic society, and is an innovative practice to promote the implementation of the energy revolution.
(1) The connotation of the new power system
New energy as the main energy is only the basic characteristics of the new power system, it has more profound connotation.
First, new power systems are a bridge between clean energy supply and demand. The essence of constructing a new power system is to meet the operation demand of a high-proportion new energy power grid, and to realize efficient interaction between charge and storage of the source network through all links of energy supply and demand.
Secondly, the new power system is an effective way to release the green value of electric energy. The new power system is conducive to the optimal allocation and dispatch of clean energy, and guides the green transformation of the energy production and consumption industry chain through the green power energy intermediary, so as to realize the smooth transmission of the green value of electric energy to the end users.
(2) Typical characteristics of new power systems
The core of the new power system is new, which has distinct characteristics:
Digital technology enables the formation of multi-network fusion. The outstanding feature of the Internet of Things era is machine social interaction. The real end users of energy are not individual people, but all kinds of energy using devices. The ultimate form of energy network must be interconnection and machine social interaction between energy using devices. The future energy network will be characterized by distributed production and utilization of energy, and evolve into self-balancing, self-operation and self-processing integrated intelligent energy system of source network and load driven by digital technologies such as cloud big thing chain.
Therefore, energy will not develop independently to form an isolated energy network. In the future, power infrastructure will become a platform. Digital technology will deepen the integration and interaction of energy network, government network and social network, and realize the integration and common development of multiple networks.
The user side will be deeply involved in the balance of the power system. Limited by the output characteristics of new energy, flexible resources will be an important factor to ensure the stable operation of the power system, and it will be economically feasible to effectively excavate the flexibility of the user side, reduce the peak-valley difference of the power system, and improve the utilization efficiency of power.
The interaction between load and storage of source network will become the normal operation of new power system, interruptible load and virtual power plant will be widely used, and power load will realize the transformation from traditional rigid and pure consumption type to flexible and both production and consumption type.
Distribution network will become the dominant force of electric power development. The process of constructing new power system is actually a revolution of distribution network. The backbone grid is usually the strongest in the traditional power system, and the system is more vulnerable as it reaches the end of the grid. However, the distribution network in the new power system will assume most of the responsibility of system balance and security and stability, and most of the transactions will be completed in the distribution network. The existing distribution network needs to be reconstructed at the physical level to become the dominant force of the power system.
Electricity trading will dominate the dispatching system. In the future, the new power system will mainly meet the transaction needs of users, and the main purpose of scheduling is to ensure the implementation of user transaction behavior with the minimum system cost. The direct transaction between users and power generation enterprises will become the sales mode of the vast majority of electricity, flexible resources will also become the core transaction content with the gradual improvement of the spot market mechanism, and most of the transactions will be completed in the distribution network, and the sale of electricity through the wall will become the main transaction mode.
Prospects for key technologies of new power systems
The construction of new power system is a systematic and long-term project, which cannot do without technological innovation and breakthrough.
First, sourcenet load storage two-way interaction technology. Through digital technology empowerment, the transformation from "source with load" to "source with load interaction" is promoted to realize intelligent, friendly and collaborative interaction of source network with load storage of multiple resources.
The second is virtual synchronous generator technology. By adding energy storage or running in the real time power state in the new energy grid-connection, and optimizing the control mode to provide frequency modulation, voltage modulation, peak modulation and phase modulation support for the system, the grid-connection friendliness of new energy is improved.
Third, long-cycle energy storage technology. The combination of long-term energy storage and large-scale scenic projects will replace traditional fossil energy to become a base load power plant with a high probability, which will have a profound impact on the construction of zero-carbon power system in the middle and later period.
Fourth, virtual power plant technology. The popularization and application of the integrated project of source network, charge and storage, as well as the rapid development of distributed energy, micro-grid and energy storage provide rich resources for virtual power plants, and virtual power plants will become an important component of power system balance.
Fifth, other technologies. The research and development and breakthrough of new energy DC networking, DC microgrid, AC-DC hybrid power distribution network and other technologies will help realize a higher proportion of new energy grid connection and guarantee the safe and stable operation of the power system.
Third, the idea and suggestion of constructing new power system
To carry out the carbon was at peak, carbon neutral, target, the power industry responsibility, construct a new energy as the main body of the new type of electric power system is given by the era of responsibility and mission, need power supply, power grid, the user and other parties to the joint efforts of the industry chain, to develop the new energy as the foundation, to increase the system flexibility to secure resources, promote the development of distributed, micro power grid and power grid integration, We will build strong power grids, strengthen technological innovation and application, achieve coordinated and integrated development of power generation, transmission and distribution, and power consumption systems, and help the power sector take the lead in carbon neutrality.
We will vigorously develop new energy sources. We will continue to promote both centralized and distributed development, orderly promote the development of new energy in resource-rich areas such as the Three North regions and the development of distributed energy in load-bearing areas in the central and eastern regions, and intensify the development of the new energy industry.
At the same time, we will promote the integrated development of the new energy industry with traditional hydropower, environmental protection, and agriculture, establish an ecological energy system, promote new forms of business such as water and landscape complementarity, fishing, agriculture, and photovoltaic desertification control, and explore a path of energy ecological development in which multiple sources of energy complement each other and cooperate with each other in wisdom.
Enhance system flexibility resources. New energy projects are encouraged to allocate a certain scale of regulatory resources such as coal power, hydropower and energy storage, and improve the stability of new energy output through the mode of "new energy + regulatory power".
We will actively promote flexible transformation of thermal power projects where conditions permit, and strive to provide economically feasible and large-scale adjustment capacity for the system. With the goal of increasing clean energy consumption and enhancing frequency and peak modulation capacity, pumped storage and electrochemical energy storage projects will be developed in a scientific and orderly manner. Strengthen the research and application of adjustable load, virtual power plant and other technologies to realize the integrated development of source network and load.
We will promote the integrated development of distributed, micro and large power grids. Strengthen the application of digital technology, through the deep link of distribution assets to build a digital power grid based on the physical architecture of traditional power grid. Support the construction of distributed renewable energy and energy storage system, and get rid of the dependence on large power grids by using nearby materials and absorbing locally, and form multiple independent microgrids, each of which provides backup support to each other, so as to achieve "green energy" nearby.
Research shows that when wind power and photovoltaic power generation share more than 30% to 40%, the frequency, voltage, power Angle stability limit and high cost of large power grid system determine the ceiling of absorbing new energy. Therefore, the integration of distributed, micro-grid and large grid will become an important support for the future power system.
We will accelerate technological innovation and its wider application. Strengthen the research and development of new energy power prediction, virtual synchronous generator, flexible DC power transmission, distributed camera and other technologies, fully tap the demand side response resources such as industrial large users and electric vehicles, improve the level of new energy consumption and utilization and ensure the security and stability of the power system through the innovation of power supply, power grid and user-side technology.
At the same time, the energy storage, virtual power plants and dc micro network technologies such as peak has cut, frequency modulation, voltage regulator is an important technical means of supporting new energy development, suggested the country level planning as a whole, at the top of a corresponding design documents, strengthen the industry guidance, increase the technical research, actively promote the related technical standards, scientific, standardized and orderly development of power industry.
Wuhan Xinshengneng is a professional power testing equipment manufacturer. We pay close attention to the development and trends of power grid related industries. For more information, visit our official website: www.whxsn.com
