Cumulative capacity of stationary Li-ion energy storage systems in Japan FY 2014-2023

In the fiscal year 2023, the cumulative capacity of stationary lithium-ion (Li-ion) battery storage systems shipped in Japan amounted to around 6.89 gigawatt-hours (GWh). Ten years earlier, the yearly capacity of shipments had only been roughly 0.38 GWh.

Is an energy storage system the same as a storage battery?

In a way, it is, but the former term emphasizes the storage function over the energy supply quality of storage batteries. Unlike your portable power bank, it may be not the grid feeding power into them but energy converters such as solar panels or wind turbines, making these stationary packs of rechargeable batteries ideal for off-grid living. To put it in perspective, a 10,000 milliampere-hours Li-ion portable power bank with a 3.85 Voltage gives you 38.5 Wh.

The different types of Li-ion battery storage systems

Most lithium-ion energy storages shipped in Japan are not off-grid but large-scale on-grid systems instead. While off-grid systems roughly supply two kWh, their on-grid counterpart exceeds seven kWh on average. This larger capacity makes them popular as emergency power supplies in a country frequently challenged by natural disasters. Large storage batteries also mitigate the discrepancy between peaks of electricity production and consumption at renewable power plants. However, for the grid-feeding use on an industrial scale, other types than Lithium-ion storage batteries are more reasonable.