Guide On Battery Energy Storage System (BESS) Projects

Battery Energy Storage System (BESS)

This handbook provides a guidance to the applications, technology, business models, and regulations to consider while determining the feasibility of a battery energy storage system (BESS) project. Several applications and use cases are discussed, including frequency regulation, renewable integration, peak shaving, microgrids, and black start capability.

For example, integrating distributed energy resources into traditional unidirectional electric power systems is difficult due to the added complexity of maintaining system reliability despite the variable and intermittent nature of wind and solar power generation, as well as keeping customer tariffs affordable while investing in network expansion, advanced metering infrastructure, and other smart grid technologies.

The key to addressing such issues is to increase power system flexibility, so that infrequent periods of excessive renewable power output do not have to be limited, and there is less need for huge expenditures in network expansion, which result in high consumer prices. Storage provides one potential source of flexibility.

Batteries have previously shown to be an economically effective energy storage solution. BESSs are modular systems that may be housed in conventional shipping containers.

This manual deconstructs the BESS into its major components and provides a foundation for calculating the expenses of future BESS initiatives. For example, battery energy storage devices can be used to overcome a number of issues associated with large-scale renewable grid integration.

Figure 1 – Schematic of A Utility-Scale Energy Storage System

Where:

• ACB – Air circuit breaker,
• BESS – Battery energy storage system,
• EIS – Eectric insulation switchgear,
• GIS – Gas insulation switchgear,
• HSCB – High-speed circuit breaker,
• kV – Kilovolt,
• LPMS – Local power management system,
• MW – Megawatt,
• PCS – Power conversion system,and
• S/S – Substation system.

First, batteries are theoretically better adapted to frequency management than the traditional spinning reserve of power plants. Second, batteries offer a cost-effective alternative to network expansion for decreasing wind and solar power generating curtailments.

Similarly, batteries help consumers avoid peak charges by providing off-grid energy during on-grid peak use hours.

Third, because renewable power generation frequently does not match electricity demand, surplus power should be reduced or exported. Surplus power can be stored in batteries and used later when renewable power supply is low and electricity demand rises.

Energy Storage System Components

The ESS components (see Figure 1) are categorized based on their function into three groups: battery components, components necessary for ensuring reliable system operation, and grid connection components. The battery system comprises the battery pack, which links numerous cells to the suitable voltage and capacity; the battery management system (BMS); and the battery thermal management system (B-TMS).

The Battery Management System (BMS) safeguards the cells against detrimental operation, specifically in terms of voltage, temperature, and current, in order to ensure dependable and secure functioning. Additionally, it equalizes the different states-of-charge (SOCs) of cells within a series connection.

The essential elements necessary for ensuring the dependable functioning of the entire system include system control and monitoring, the energy management system (EMS), and system thermal management.

Figure 2 – Schematic of A Battery Energy Storage System

Where:

• BMS – battery management system, and
• J/B – Junction box.

System control and monitoring refers to the overall supervision and data collection of various systems, such as IT monitoring and fire protection or alarm units. It is often integrated into the supervisory control and data acquisition (SCADA) system.

The EMS is accountable for the regulation, administration, and dispersion of system power flow. System thermal management encompasses all operations pertaining to the regulation of temperature, airflow, and air conditioning within the containment system.

The power electronics can be categorized into two main components: the conversion unit, which facilitates the transfer of electricity between the grid and the battery, and the control and monitoring components, which include voltage sensing units and thermal management systems for cooling the power electronics components using fans.

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