Energy storage systems: a core technology for future power supply
With the rapid development of renewable energy sources, energy storage devices with fast response capability are needed in the power system to meet the demand for electricity and to improve the quality of power supply. From the perspective of the power grid, energy storage technology will make the power system more flexible and economical. From the perspective of renewable energy generation, energy storage technology can improve the stability and reliability of renewable energy and reduce the impact on the power grid.
The role of energy storage system
The energy storage system has two main roles:
One is to smooth the output of electrical energy, and the other is to realize electrical energy storage. It is mainly used in renewable energy grid connection, grid peak shifting and frequency adjustment, improving the security and stability of the power system, and realizing power quality regulation and frequency regulation. At the same time, the energy storage system can improve the reliability and stability of renewable energy power generation, reduce the impact on the grid, and enhance the adaptability of the grid to large-scale renewable energy.
Energy storage technology
Energy storage technology refers to energy conversion in order to overcome the volatility of the grid load, improve power quality, reduce system reserve capacity and improve the utilization rate of power generation resources. Energy storage technologies include lithium-ion batteries, sodium-sulfur batteries, compressed air energy storage, flywheel energy storage, pumped storage and thermal storage. According to the operating principle of energy storage technology, it can be divided into physical energy storage and chemical energy storage.
Development status of energy storage technology
The research and application of energy storage technology is an important part of renewable energy development. With the expanding scale of installed renewable energy power generation, energy storage technology plays an important role in ensuring the safe and stable operation of the power grid, improving the efficiency of the power system, promoting new energy consumption, and guaranteeing new energy output.
At present, China has formed to electrochemical energy storage, compressed air energy storage and flywheel energy storage as the representative of various types of energy storage technology, as well as pumped storage as the representative of cross-seasonal and cross-regional power conditioning technology, in the power system has been widely used.
At present, large-scale electrochemical energy storage systems have been established in China. By the end of 2018, the installed capacity of pumped storage power stations in operation in China reached 6.3 million kilowatts, which is the largest pumped storage power station in the world, and ranks second in the global ranking of energy storage scale.
Development and Prospects of Energy Storage Technology in China
China’s renewable energy power generation installed capacity is increasing rapidly, while the volatility and intermittency of wind power and photovoltaic power generation put forward higher requirements for grid stability. In order to improve the stability and reliability of renewable energy power generation, energy storage technology has been developing rapidly in China. At present, several energy storage projects have been put into operation in China, including pumped storage, lithium-ion batteries, compressed air energy storage and so on.
With the development of new energy generation technology, China is formulating and improving relevant standards to support the application of energy storage technology in power systems. At the same time, China has also increased its investment in the research and development of energy storage technology. At present, the country has carried out different forms of energy storage pilot demonstration projects in several regions, and these projects have laid a solid foundation for promoting the application of energy storage technology in China.
Conclusion
Energy storage system is one of the core technologies for the future development of the power system and will become the core technology for future power supply. From the perspective of power grid, energy storage technology can improve the flexibility and economy of power supply, thus improving the quality of power supply; from the perspective of renewable energy power generation, energy storage technology can improve the stability and reliability of renewable energy and reduce the impact on the power grid.
Although energy storage technology is widely used in the power system, its development is still facing many challenges, such as high cost of large-scale energy storage equipment, low energy density and power density, security and reliability need to be improved.