What is a Battery Energy Storage System?
A battery energy storage system (BESS) is a type of energy storage technology that uses a group of batteries to store electrical energy. This technology is used in the grid to stabilize power distribution, providing a fast-responding dispatchable source of power.
How Does it Work?
Battery energy storage systems are designed to deliver their full rated power for durations ranging from 1 to 4 hours, with emerging technologies extending this to longer durations. They can be used for short-term peak power demand and for ancillary services, such as providing operating reserve and frequency control to minimize the chance of power outages.
History and Development
The use of battery energy storage systems in the grid has been growing rapidly. In 2025, the worldwide nonprofit Volta Foundation reported global BESS deployments grew by 104 GW/257 GWh as costs fell 31% year on year. 40% of the cumulative BESS capacity was installed in 2025 alone.
Comparison to Other Energy Storage Technologies
Battery storage plants require no deliveries of fuel, are compact compared to generating stations, and have no chimneys or large cooling systems. This makes them a viable option for rapid installation and placement in urban areas, close to customer load, or even inside customer premises. In comparison to pumped-storage power plants, the largest individual battery storage system is an order of magnitude less, but grid batteries can be deployed in large numbers for greater redundancy and overall capacity.
Cost and Efficiency
The cost of battery energy storage systems has been decreasing rapidly. The levelized cost of storage (LCOS) has fallen by half every 4.1 years, from 2014 to 2024. The price was US$150 per MWh in 2020, and further reduced to US$117 by 2023. This makes battery energy storage systems a cost-effective option for energy storage.
Applications and Examples
Battery energy storage systems are used in various applications, including:
- Stabilizing the grid by providing a fast-responding dispatchable source of power
- Reducing peak power demand
- Providing ancillary services such as operating reserve and frequency control
- Supporting renewable energy sources by providing energy storage
FAQ
What is the typical duration of a battery energy storage system? Battery energy storage systems are designed to deliver their full rated power for durations ranging from 1 to 4 hours.
How has the cost of battery energy storage systems changed over time? The cost of battery energy storage systems has been decreasing rapidly, with the levelized cost of storage (LCOS) falling by half every 4.1 years from 2014 to 2024.
What are the benefits of using battery energy storage systems? The benefits of using battery energy storage systems include stabilizing the grid, reducing peak power demand, providing ancillary services, and supporting renewable energy sources.
How does the size of a battery energy storage system compare to other energy storage technologies? The largest individual battery storage system is an order of magnitude less than the largest pumped-storage power plants, but grid batteries can be deployed in large numbers for greater redundancy and overall capacity.
What is the current cost of battery energy storage systems? The current cost of battery energy storage systems is US$117 per MWh, as of 2023.