1.1 Transformation: New Power Systems Meet Challenges
In the process of “dual carbon”, the amount of wind and solar power generation is rapidly increasing. The energy supply structure will gradually evolve with the “dual carbon” process, and the share of non fossil energy electricity supply will rapidly increase. At present, China still heavily relies on thermal power. In 2020, China’s thermal power generation reached 5.33 trillion kWh, accounting for 71.2%; The proportion of electricity generation is 7.51%.
The acceleration of wind power and photovoltaic grid connection poses challenges to new power systems. Conventional thermal power units have the ability to suppress unbalanced power caused by changes in operating mode or load during grid operation, and have strong stability and anti-interference. With the advancement of the “dual carbon” process, the proportion of wind and solar power is gradually increasing, and the construction of new power systems faces many challenges.
1) Wind power has strong randomness and its output exhibits reverse load characteristics. The maximum daily fluctuation of wind power can reach 80% of the installed capacity, and the random fluctuation makes wind power unable to respond to power imbalances in the system. The peak output of wind power is mostly in the early morning, and the output is relatively low from morning to evening, with significant reverse load characteristics.
2) The fluctuation value of photovoltaic daily output can reach 100% of the installed capacity. Taking the California region of the United States as an example, the continuous expansion of photovoltaic installed capacity has raised the demand for rapid peak shaving of other power sources in the power system, and the fluctuation value of photovoltaic daily output can even reach 100%.
Four basic characteristics of the new power system: The new power system has four basic characteristics:
1) Widely interconnected: forming a stronger interconnection network platform, which can achieve seasonal complementarity, wind, water and fire mutual adjustment, cross regional and cross domain compensation and regulation, and achieve the sharing and backup of various power generation resources;
2) Intelligent interaction: integrate modern communication technology with electric power Technological convergence to build the power grid into a highly perceptive, two-way interactive and efficient system;
3) Flexible and flexible: The power grid should fully have the ability to regulate peak and frequency, achieve flexible and flexible properties, and enhance anti-interference ability;
4) Safe and controllable: achieving coordinated expansion of AC and DC voltage levels, preventing system failures and large-scale risks.
1.2 Drive: Three side demand guarantees rapid development of energy storage
In the new type of power system, energy storage is required for multiple loop nodes, forming a new structure of “energy storage+”. There is an urgent demand for energy storage equipment on the power supply side, grid side, and user side.
1) Power side: Energy storage can be applied to power frequency regulation auxiliary services, backup power sources, smooth output fluctuations, and other scenarios to solve the problems of grid instability and power abandonment caused by wind and solar power generation.
2) Grid side: Energy storage can participate in peak shaving and frequency regulation of the power grid, alleviate congestion of transmission equipment, optimize power flow distribution, improve power quality, etc. Its core role is to ensure the stable operation of the power grid.
3) User side: Users can equip energy storage devices to save costs through peak shaving and valley filling, establish backup power sources to ensure power continuity, and develop mobile and emergency power sources.
Power side: Energy storage has the largest application scale on the power side. The application of energy storage on the power side mainly includes improving energy grid characteristics, participating in auxiliary services, optimizing power flow distribution and alleviating congestion, and providing backup. The focus of power supply is mainly on maintaining the balance of power grid demand, ensuring the smooth integration of wind and solar power.
Grid side: Energy storage can enhance the flexibility and mobility of the system layout, enabling temporal and spatial allocation of transmission and distribution costs. The application of energy storage on the grid side includes four aspects: energy conservation and efficiency enhancement, delayed investment, emergency backup, and improvement of power quality.
User side: mainly aimed at users. The applications of energy storage on the user side mainly include peak shaving and valley filling, backup power supply, intelligent transportation, community energy storage, power supply reliability, and other fields. The user sid
Post time: Jun-29-2023