Concept and difference between ESS and BESS

ESS(Energy Storage System) refers to the entire system that stores electricity and supplies it when needed. ESS is installed at various stages of the power system, such as power plants, transmission and distribution, and consumers, and is used for various purposes, such as peak demand management, power auxiliary services, and uninterruptible power supply (UPS). The core roles of ESS are stabilizing power supply, supplementing output fluctuations of new and renewable energy, and supplying emergency power during power outages.

ESS can be broadly classified into three types based on storage method:

• Mechanical storage : pumped storage (PHS), compressed air storage (CAES), flywheels, etc.

• Chemical storage : Battery-based storage such as lithium-ion, sodium-sulfur, and lead-acid batteries.

• Electromagnetic storage : supercapacitors, superconducting magnetic energy storage (SMES), etc.

In other words, ESS is a superordinate concept that encompasses not only batteries but also various physical, chemical, and electromagnetic methods.

BESS(Battery Energy Storage System) is a sub-concept of ESS, and refers only to a system that stores energy using batteries . BESS generally utilizes various battery technologies such as lithium-ion, sodium sulfur, lead-acid, and flow batteries, and is mainly used to store electricity in conjunction with renewable energy (solar power, wind power, etc.) and supply it when needed.

BESS has the following features:

• High energy density : More energy can be stored in the same volume or weight, making installation space efficient.

• Modularity and scalability : Multiple battery modules can be connected to freely expand capacity.

• Ease of installation : Pre-assembled container-type BESS has recently appeared, making on-site installation quick and maintenance easier.

• Main applications : grid support, peak power supply, renewable energy integration, emergency power supply, etc.

Comparison of ESS and BESS

Reasons for the recent expansion of BESS

• Ease of Installation : The pre-assembled container-type BESS allows for quick installation and movement, allowing immediate application to various sites.

• High energy density : With the development of high-efficiency batteries such as lithium-ion, more energy can be stored in the same space.

• Diffusion of renewable energy : Demand for BESS is rapidly increasing to supplement the output fluctuations of intermittent power sources such as solar and wind power.

• Operational Efficiency : Modular design allows for easy capacity expansion and maintenance.

summation

• ESS refers to all systems that store and supply electricity (including mechanical, chemical, and electromagnetic methods).

• BESS is a type of ESS that is a storage system that uses only batteries.

• Recently, BESS has been growing rapidly in the ESS market due to its advantages such as high energy density, ease of installation, and connectivity with renewable energy.