Strengthening energy storage construction as power system transformation is underway

China Energy Storage Network News: Reporters conducted research in Sichuan, Ningxia, Shaanxi, Xinjiang and other places and found that in the process of exploring the construction of a new power system with new energy as the main body, many places have carried out overall planning research, demonstration areas and pilot demonstration project construction, but are facing difficulties such as increasing difficulty in ensuring power supply, challenges in the safe and stable operation of the power grid, and increased power grid investment and system costs. The industry said that this work has a high trial and error cost, and it is advisable to make full use of mature technologies and existing systems and deeply tap potential, support the development of new technologies, actively and steadily realize transformation step by step, and promote the construction of a unified national power market system to promote the wider consumption of new energy.

Traditional power systems are transforming

Many parties have stated that the realization of the dual carbon goals and the construction of a new power system is a long-term, systematic project. my country is currently in the transformation stage of its traditional power system, that is, the rapid development of new energy, and the impact of a high proportion of renewable energy access and a high proportion of power electronic equipment application are in the "quantitative change" stage. In this stage, conventional power sources are still the main source of electricity supply, with new energy as a supplement, and real-time balance of power generation and consumption is the main feature.

Xiang Li, deputy director of the Development Planning Department of State Grid Ningxia Electric Power Co., Ltd., introduced that Ningxia has taken the power transmission project, backbone grid construction project, system regulation and improvement project, modern distribution network construction project, intelligent control upgrade project and equipment lean operation and maintenance project as the main means to build a new power system. It is planned that by 2030, the proportion of new energy installed capacity will exceed 70%, new energy will gradually transform into the main supply of electricity, and Ningxia's new power system will be basically completed.

The Sichuan New Power System Research Institute is the first provincial-level new power system research platform in the country. Xu Weiting, director of the research and development department of the institute, introduced that the institute has worked with well-known universities and research institutes in and outside the province to create a model of a demonstration project for the complementary power generation of hydropower, photovoltaic and storage. At the same time, it has formed a series of theoretical achievements to effectively ensure the safe delivery and efficient consumption of clean energy in Sichuan, targeting the risks of ultra-low frequency oscillation in high-proportion hydropower systems, the stability of new energy access, and the lack of system frequency regulation capabilities.

In Xinjiang, State Grid Xinjiang Electric Power Co., Ltd. focuses on the clean power supply side, intelligent power grid side, and electrification of load side, and studies supporting policy mechanisms to promote the formation of coordinated interaction between sources, grids, loads and storage. At the same time, it promotes the inclusion of the four prefectures in southern Xinjiang into the State Grid Corporation's new power system demonstration area, pilots the implementation of the "new energy + energy storage" development model, and supports the development of new energy in southern Xinjiang; implements the source-grid-load-storage coordinated control project demonstration, promotes the transformation of the power grid into a source-grid-load-storage intelligent interactive model of "source follows load, load follows grid", and improves the power supply guarantee capability; builds the Kuche "photovoltaic + hydrogen production" demonstration project, gives full play to the characteristics of hydrogen production by electricity as a highly adjustable load, and effectively improves the flexibility and safety of the power system.

Stable power supply faces certain challenges

During the transformation phase of the traditional power system, industry insiders said they faced several major challenges.

——Major challenges are faced in ensuring power supply. Zhao Zhiqiang, president of Xinjiang Economic Research Institute of State Grid, said that under the background of orderly reduction of coal-fired power and large-scale development of new energy, new energy has become the biggest variable affecting power supply due to its obvious characteristics of "no wind in extremely hot weather", "no light in late peak hours" and "large installed capacity and small power consumption". It is useless and cannot withstand the peak load at critical moments.

——The safe and stable operation of the power grid faces major challenges. As the proportion of new energy sources gradually increases, it will replace traditional thermal power as the main energy supply. The rotational inertia of the power system continues to decrease. The safety issues such as insufficient dynamic reactive power support, insufficient frequency regulation and stability, and the interweaving of traditional synchronous stability and new forms of stability in system operation are becoming increasingly prominent. The transient support characteristics and pressure resistance of new energy equipment are insufficient. When the power grid is disturbed and causes voltage and frequency fluctuations, it is easy to cause chain disconnection accidents, making the fault evolution process more complicated and increasing the risk of large-scale power outages in the system.

——Increase grid investment and system costs. Most new energy bases are located at the end of the grid, and the number of hours of new energy utilization is less than that of conventional power sources. Large-scale development has led to a continuous increase in the scale of new energy collection and transmission projects and their upstream transmission channel supporting reinforcement projects, a substantial increase in grid investment demand, and a much shorter construction period for new energy than for transmission projects, making it difficult to effectively match construction schedules.

——Higher requirements are put forward for major scientific and technological research and promotion and application. The new power system involves many fields and has a wide impact, and major technical support applications are the key guarantee. Digital technologies represented by 5G, big data, and the Internet of Things are accelerating their integration with power grid technologies. New technologies, new formats, and new models are forcing innovation in power technology. It is necessary to actively explore the power industry structure, business model, technology system, and management system that are compatible with it.

Accelerate the deployment of measures to deal with the difficulties during the transition period

Shu Yinbiao, an academician of the Chinese Academy of Engineering, said in a signed article that the energy and power industry is technology-capital intensive, highly path-dependent, and has extremely high trial-and-error costs for technology routes, so it is appropriate to adopt a gradual transitional development approach. In the near term, we should focus on tapping the potential of mature technologies, supporting the rapid development of new energy, and simultaneously carrying out disruptive technology research; in the long term, after breakthroughs in disruptive technologies, we should promote the gradual transformation of the power system to a new form that adapts to disruptive technologies.

During the transition period, the industry recommends starting from both "software" and "hardware" in order to ensure power security and low-carbon development. In terms of "software", during the transition period, the important role of the market in allocating resources should be fully utilized. Market barriers between provinces should be broken down, a transmission and distribution price mechanism that adapts to large-scale market operations should be established, and a coordinated interaction mechanism between grid, source, load and storage should be improved to promote the construction of a unified national power market.

Secondly, comprehensively expand new models of electricity consumption. Yuan Jiahai, a professor at the School of Economics and Management of North China Electric Power University, suggested activating user-side resources to achieve a better balance of electricity. As the proportion of new energy increases, the output is more arbitrary. At this time, it is not energy that follows load, but only energy and load interaction. When the output of new energy is relatively low, guide demand and use less electricity as much as possible. When new energy is in full swing, the opposite is true. In the final analysis, there must be a market incentive mechanism.

In terms of "hardware", first, we need to improve the construction of the power supply side. We will promote the construction of large-scale new energy bases in the western and northern regions, develop distributed new energy in the eastern and central regions according to local conditions, and promote the gradual expansion of offshore wind power to the far seas. Coal-fired power will play a bottom-up guarantee role from "increasing capacity and controlling quantity" and "controlling capacity and reducing quantity" to "reducing capacity and reducing quantity"; focus on promoting the construction of high-quality hydropower in the southwest; carry out nuclear power construction in coastal areas in a safe and orderly manner, and promote inland nuclear power construction in a timely manner.