In recent years, with the integration of new energy sources such as wind power, hydropower, and solar power into the grid, the dispatch pressure on the power grid system has increased, and the widespread application of energy storage cells has become urgent. In the power system, the main roles of energy storage cells include the following four points.
① Smoothing fluctuations: Energy storage batteries can quickly enter the charging or discharging state according to the user demands in the power system, fully meeting the electricity needs in social life and industrial production, and alleviating the instability of power supply caused by grid load peaks and fluctuations in new energy power.
② Peak shaving and valley filling: Power load exhibits significant peaks and valleys influenced by user demand. Energy storage batteries can release energy during peak load periods and store energy during low load periods, thereby achieving the goal of peak shaving and valley filling.
③ Improving power quality: Energy storage batteries can improve power quality by peak shaving, valley filling, and smoothing fluctuations, ensuring the stability and reliability of power supply.
④ Delaying grid upgrade and renovation: While improving power quality, energy storage cells can also reduce grid system losses, prolong the service life of electrical equipment, and save costs for grid upgrade and renovation.
Currently, energy storage cells are mostly used in the field of new energy generation, including wind power generation, hydropower generation, photovoltaic power generation, and bio-power generation. The electricity output of these generation methods is characterized by randomness and fluctuations, which greatly impact the safety and stability of the power system. The introduction of energy storage battery systems is intended to ensure the stability of the grid system. When the grid load fluctuates, the energy storage system can quickly respond to ensure power balance. A large number of energy storage cells can also solve power fluctuation issues caused by the randomness of new energy generation. The regulatory roles of energy storage battery systems in different power grids also differ, with some grid systems capable of ensuring stable grid power, voltage, and frequency, while independent grids can only balance grid power or stabilize voltage.
After years of development, there are now various types of energy storage cells. The following are three types of energy storage cells with significant characteristics. First, lithium batteries are widely used in the current power system due to their high efficiency, high-power charging and discharging, and long lifespan. However, rapid charging and discharging pose safety hazards, and it is difficult to recycle and reuse discarded batteries. Second, lead-carbon batteries, which combine traditional lead-acid batteries with supercapacitors, have advantages such as high power and long lifespan. However, the charge-discharge rate and discharge depth of lead-carbon batteries still lag behind lithium batteries. In addition, there are liquid metal batteries with advantages such as fast response speed, high efficiency, stable performance, long lifespan, and economic and environmental friendliness. However, the technology is still immature and is in the experimental and verification stage.
With the construction of smart grids, energy storage cells have become a key technology to ensure the safe, stable, and efficient operation of the power grid, playing an important role in peak shaving, valley filling, improving power supply quality, and delaying grid upgrade and renovation. Currently, lithium batteries have been widely used in grid energy storage systems, while new technologies such as superconducting batteries, lead-carbon batteries, and liquid metal batteries are in the experimental and promotion stage. The widespread adoption of energy storage cells will greatly enhance the safety and stability of the power grid system.