How do BESS work?

How do bess work

The core functionality of a BESS revolves around storing electricity produced during low demand and releasing it during peak periods of demand. This not only stabilizes the grid but also makes energy use more economically efficient.

What are the main components of BESS

1. Battery cells: The main storage component which can vary in type, including lithium-ion and lead-acid batteries as well as different chemistry type.
2. Battery Management System (BMS): Monitors battery health and functionality to ensure safe operation.
3. Power Conversion System (PCS): Converts electricity from DC to AC and vice versa, facilitating the interaction with the electric grid.
4. Energy Management System (EMS) and SCADA: These systems manage the charging/discharging process and optimize the performance and integration of BESS into the broader power system.

Battery energy storage system benefits

• Reliability: Provides a stable energy supply and enhances grid resilience.
• Economic Efficiency: Reduces energy costs by utilizing stored energy during peak price periods.
• Environmental Impact: Supports the integration of renewable energy sources, contributing to a reduction in carbon emissions.
• Reaction time: you can have power for charging and discharging in less than a second.

Despite the advantages, BESS face challenges such as high initial costs, maintenance needs, and technological limitations concerning energy capacity and lifespan.

How is BESS connected to the grid

BESS connects to the electrical grid through a series of components that manage both charging and discharging processes. Energy from the grid is converted from alternating current (AC) to direct current (DC) by a rectifier to charge the batteries.

When energy needs to be released back to the grid, an inverter converts the DC from the batteries back to AC, matching the grid’s frequency and voltage requirements. The system can include transformers to adjust voltage levels (usually for high power applications), and protective equipment like circuit breakers and disconnect switches to ensure safety and reliability (based on distribution grid provider requirements).

Control systems oversee the entire operation, optimizing when to store energy based on grid demand and energy costs, and when to release it to maximize efficiency and support grid stability. 

How long will the BESS last

The typical lifespan of BESS ranges from 5 to 15 years, influenced by factors like the depth of discharge and the cycling of the batteries.

Advances in technology and practices in recycling and repurposing batteries are important for enhancing the sustainability of BESS solutions.

For a better lifespan of the system, it is critical to have a proper design and operate it in good conditions – including proper temperature management (liquid preferred) and a range of other small but crucial technologies such as overvoltage protections, smart EMS, etc..