Research shows that as the deployment of battery energy storage systems grows, their uses are also expanding accordingly

　　According to a survey conducted by the U.S. Energy Information Administration (EIA), as more and more battery energy storage systems are added to the grids of various states in the United States, their application scenarios and uses have changed. Utility-scale battery energy storage systems obtain energy from the grid during a specific period and release it to the grid when needed. This capability creates more opportunities for power dispatch optimization strategies based on the power system or economic conditions.

　　Frequency response is still the most common use of battery energy storage systems, but as more and more battery energy storage systems are connected to the grid, applications such as response backup, arbitrage, and load tracking have become more and more common.

　　The 2020 report on power generation facilities released by the U.S. Energy Information Administration (EIA) collects data on these energy storage applications from battery energy storage developers. On average, there are 2.2 use cases for battery energy storage systems deployed by energy storage developers.

　　The most common use case for battery energy storage systems is frequency response. Frequency response is a service that keeps the grid frequency at 60 Hz as much as possible. Deviations below 60 Hz will cause protective tripping of the generator, which will result in a decrease in the stability of the power system. The battery energy storage system is particularly suitable for frequency adjustment, because its power output is very fast, and the battery energy storage system can quickly absorb surges. By the end of 2020, there will be a total of 885MW of battery energy storage systems in the United States (accounting for 59% of the total installed capacity of utility-scale battery energy storage systems) for frequency response.

　　Response backup is an auxiliary service that can quickly respond to power system power interruptions, such as sudden power interruptions or rapid changes in demand. In areas where the proportion of power generation from energy sources such as wind and solar energy is relatively high, the amount of power generated will fluctuate with changes in wind speed or cloud cover, and resources that can respond quickly are often required. By the end of 2020, the battery energy storage system with an installed capacity of 583MW (accounting for 39% of the total installed capacity) will be used for response backup.

　　Arbitrage is a strategy that buys electricity during low-price periods and sells electricity during high-price periods. Battery energy storage systems support this strategy by charging when electricity prices are low and discharging when electricity prices are high. From 2019 to 2020, the battery energy storage system used in this use case in the United States increased by 390 MW, which is the fastest growing among various use cases. By the end of 2020, there are 586 MW battery energy storage systems (37% of total installed capacity) in the United States for arbitrage.

　　Load tracking is an operating strategy in which a generator changes its output to match changes in power demand or load. The battery energy storage system is used for load tracking, because its power output can be digitally controlled, so it can respond to load changes faster and more accurately. U.S. Energy Information Administration (EIA) survey data shows that in 2020, there will be nearly 400MW battery energy storage systems for load tracking.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate battery is a perfect replacement for lead-acid batteries, and it is the first choice for grid-connected peak shaving, off-grid energy storage, photovoltaic energy storage, UPS, data center and other industries.

　　Solar power generation system with lithium battery energy storage system is a very promising clean energy.