How much do you know about the new power system?

China Energy Storage Network News: State Grid recently announced that its grid investment in 2022 will be 501.2 billion yuan (grid investment caliber), breaking the 500 billion yuan mark for the first time, an increase of 8.84% year-on-year, a record high. In 2021, State Grid plans to invest 473 billion yuan in the grid, and in 2022 it plans to increase by about 6% year-on-year, showing an overall trend of steady growth.

During the 14th Five-Year Plan period, the State Grid Corporation of China plans to invest US$350 billion (about RMB 2.23 trillion). The Southern Grid Corporation plans to invest about RMB 670 billion in grid construction during the 14th Five-Year Plan period, a 36% increase over the 13th Five-Year Plan period. The two major power grid companies will invest more than RMB 2.9 trillion in grid construction during the 14th Five-Year Plan period, 13% higher than the national grid investment during the 13th Five-Year Plan period.

In addition to the steady growth of overall investment, more important is the structural change. In the future, the new power system will be the main direction of construction. The following Wall Street News and Jianzhi Research will give you an in-depth interpretation of what the new power system is.

Highlights of this article

1. What is the new power system? How is it different from the traditional power system?

2. How does the new power system work?

3. How does “source-grid-load-storage” work in a coordinated manner?

01. What is the new power system?

There is no clear official definition of the new power system, but compared with the traditional power system, the "new" of the new power system is mainly manifested in the following aspects:

First, the power supply structure has shifted from being dominated by coal-fired power generation units with controllable and continuous output to being dominated by new energy power generation units with highly uncertain and weakly controllable output.

Second, the load characteristics have changed from the traditional rigid, pure consumption type to a flexible, production and consumption type.

Third, in terms of grid structure, the traditional power system is mainly one-way step-by-step power transmission, while the new ones include large AC/DC hybrid power grids, microgrids, local DC power grids and energy Internet with adjustable loads.

Fourth, the transformation of operating characteristics. The traditional power grid is a real-time balancing mode of "source follows load" and a large-scale integrated control mode. The new power system is a transformation to a non-complete real-time balancing mode of "source, grid, load and storage" collaborative interaction and a large-scale and micro-grid collaborative control mode.

The five basic characteristics of the new power system are clean and low-carbon, safe and controllable, flexible and efficient, intelligent and friendly, and open and interactive. On March 15, 2021, General Secretary Xi Jinping presided over the ninth meeting of the Central Financial and Economic Commission and proposed deepening the reform of the power system and building a new power system with new energy as the main body. The concept of the new power system was born based on this background.

In short, the new power system needs to be clean, low-carbon and intelligent. The new power system is actually an upgrade of my country's traditional power system. However, the upgrade dimension is relatively broad, including the supply side, the power consumption side, the power grid measurement and the comprehensive upgrade of the whole system.

Why does my country’s power system need to transform?

Because the traditional power industry is mainly based on thermal power, CO2 emissions from the power industry account for about 40% of my country's total CO2 emissions. The next largest CO2 emitters are industry, construction and transportation, with the power industry accounting for the highest proportion. Therefore, to achieve the "3060" dual carbon target, the power industry naturally has to transform.

The new power system places more emphasis on "new energy" as the main body, and aims to significantly increase the proportion of new energy power generation such as photovoltaics and wind power. The core is a high proportion of renewable energy and a high proportion of power electronic equipment.

From the perspective of newly installed capacity of various power sources, the proportion of wind power and solar power generation has increased year by year, especially in 2020. By the end of 2020, thermal power accounted for 57% of my country's total power installed capacity. It is expected that from the 14th Five-Year Plan, the proportion of new energy installed capacity will continue to rise. In 2020, my country's solar power installed capacity accounted for 11%, wind power installed capacity accounted for 13%, hydropower installed capacity accounted for 17%, and nuclear power installed capacity accounted for 2%.

The ultimate goal of building a new power system is to decarbonize the power system, so as to achieve the goal of new energy accounting for more than 50% of total installed capacity around 2035, and new energy power generation accounting for more than 50% of total power generation in 2045.

Figure: Newly installed capacity of various types of power sources (GW)

Source: China Electricity Council, Northeast Securities

So in fact, all operation modes of the new power system are essentially to better and actively adapt to the development trend of a high proportion of renewable energy, thereby increasing the terminal electrification rate and better supporting greenhouse gas emission reduction.

02. How does the new power system work?

The operation of the new power system mainly revolves around the following aspects:

First, new energy will gradually become the main installed capacity; second, terminal energy consumption will be highly electrified; third, efficient development and utilization of new energy and friendly access to various loads will be achieved. Fourth, the operation mechanism of the power system will be transformed.

The overall power system can be divided into six major links: power generation, transmission, transformation, distribution, sales and dispatching.

In the past, the operation mode of the power system was mainly that large power sources such as thermal power, hydropower, and nuclear power were connected to the large power grid through voltage boosting, and then the power transmission process was completed through high voltage, ultra-high voltage and other transmission methods, and then the electric energy was transmitted to the load end through voltage reduction, which is the traditional operation mode of "source follows load".

However, the focus of power generation in the new power system has changed. In the future, it will be mainly based on new energy sources such as photovoltaic and wind power. In this way, the original centralized power supply mode will be changed to a "centralized and distributed" co-development mode. At the same time, due to the volatility, intermittent and random characteristics of photovoltaic and wind power, energy storage becomes particularly important in the operation of the new power system. Therefore, the new power system is to establish an operating mode of "source, grid, load and storage", that is, the coordinated interaction of power supply, grid, load and energy storage to achieve safe and stable operation.

03. How does “source-grid-load-storage” work in a coordinated manner?

1. Energy transmission requires coordinated development of the main grid, distribution grid, and energy storage

Main network

In the future, the "source" end will realize a power generation pattern with wind power, photovoltaic power and other new energy power generation as the main body, and thermal power as the auxiliary. However, due to the uneven distribution of energy and load in my country, the northwest region is mainly a resource concentration area, while the load area is mainly in the Yangtze River Delta in the Middle East. Many new energy power stations such as wind and solar are also distributed in the northwest region. In this way, it is necessary to increase the construction of ultra-high voltage in terms of energy transportation, that is, while maintaining the local consumption of wind and solar power generation, accelerate the construction of power transmission trunk channels and the level of interconnection between provinces. Recently, the State Grid has also released a series of documents such as the "14th Five-Year Plan" ultra-high construction. We have previously explained ultra-high voltage in detail in the article "State Grid's "14th Five-Year Plan" Ultra-High Acceleration, One Article to Help You Understand Ultra-High Voltage". Strengthening ultra-high voltage construction will help large power grids to play a role in the configuration of clean energy.

Distribution network

The "network" end mainly refers to the distribution network. Let's first talk about what the distribution network is. The distribution network is a system that receives electricity from the transmission network or regional power plants, connects to users locally or step by step through distribution facilities, and distributes electricity to users, including urban distribution networks and rural distribution networks.

In the new power system, the distribution network needs to be expanded and renovated to improve the reliability of electricity use. During the 13th Five-Year Plan period, my country has accelerated the construction of the distribution network, mainly focusing on the transformation of rural power grids. By 2020, my country's main distribution network indicators have been at the forefront of the world, and the distribution automation rate has reached 90%. However, problems still occur frequently. For example, during the peak period of electricity load in hot summer weather, local power shortages may occur. Guangdong, Anhui and other places also implement some peak power restrictions and seasonal peak electricity price policies. The power shortage is mainly due to the insufficient local capacity of the distribution network and the low mutual assistance capacity of the inter-provincial power grid and other power market mechanism reasons. Therefore, to solve the problem of power shortage during peak load periods, it is necessary to expand, transform and upgrade the distribution network, and connect some local microgrids and energy storage to solve it.