Grid-connected battery energy storage system: a review on application and integration

Battery energy storage system (BESS) has been applied extensively to provide grid services such as frequency regulation, voltage support, energy arbitrage, etc. Advanced control and optimization algorithms are implemented to meet operational requirements and to preserve battery lifetime. While fundamental research has improved the understanding of battery characteristics, a lack of insights into BESS applications and low data transparency limit the understanding of battery usage. This work reviews recent advancements in BESS grid services, with a focus on use cases and synergies with other components. After reviewing the parameters to describe the hardware features, a quantitative framework is proposed to assess the usage pattern of BESS applications in long term, which is further implemented for an overview of the BESS duty profiles in grid applications. Specifically, the frequency regulation service is emphasized, and the cross-cutting integrations with energy storage, energy production, and energy consumption components are summarized. Additionally, an elaborate survey of BESS grid applications in the recent 10 years is used to evaluate the advancement of the state of charge, state of health, and technical and economic research. With a comprehensive review of the BESS grid application and integration, this work introduces a new perspective on analyzing the duty cycle of BESS applications, which enhances communication of BESS operations and connects with technical and economic operations, including battery usage optimization and degradation research. It provides an overview of the BESS use cases in grid applications and paves the way for further application-oriented battery research.