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Grid-scale battery energy storage system containers placed outdoors near solar panels and a wind turbine, representing a renewable energy and ESS setup
Gustav NymanTuesday, 18 June 20245 min read

Understanding Energy Management for Energy Storage Systems

Energy Storage Systems (ESS) are becoming increasingly vital in the global push for renewable energy. Understanding how to manage these systems effectively is crucial as the demand for efficient and sustainable energy solutions grows.

This blog post explains:

  • How energy management works inn an ESS
  • The functional differences between Battery Management Systems (BMS), BESS (Battery Energy Storage Systems) Controller, and Energy Management Systems (EMS)
  • The main energy storage technologies used today
  • Best practices for ensuring performance, safety and longevity


Read more:
BESS is here to stay in the energy market

 

 

Understanding Energy Management:

What It Means

Energy management refers to monitoring, controlling, and conserving energy within a system. Effective management helps ensure: 

  • Efficient charging and discharging
  • Extended battery life through optimal operating conditions
  • Consistent system performance
  • Compliance with grid requirements
  • Improved safety and reduced risk of failure
  • Lower operating costs and better revenue potential

At its core, energy management is about making sure that energy is stored and released at the right time, in the right way, to deliver the highest possible value. 


BMS vs. BESS Controller vs. EMS: What Functions Does the Control Software in an ESS System Handle?

 

Battery Management System (BMS)

A BMS is integral to the safe and efficient operation of batteries within an ESS. The primary functions of a BMS include:

  • Monitoring: Constantly measuring the voltage, current, and temperature of the battery cells and modules.

  • Balancing: Ensuring all cells are charged equally to extend battery life and improve performance.

  • Protection: Preventing conditions such as overcharging, over discharging, overcurrent, short-circuit, and overheating, which all could damage the battery.

  • Data Logging: Recording performance metrics for analysis and maintenance purposes.

 

BESS Controller (Local EMS)

A BESS Controller, also referred to as a local EMS, acts as a central hub, coordinating between the BMS, Power Conversion System (PCS), and subsystems and provides a user-friendly interface for monitoring and controlling an ESS.

Functions of a BESS Controller include:

  • Control and Coordination: Manages and coordinates the operation of all individual components within the BESS, including battery modules, inverters, and other ancillary equipment.

  • Grid Compliance: Ensures that the ESS operates within the regulatory requirements and standards of the power grid.

  • User Interface: Allowing operators to monitor the entire energy storage system, operating conditions, performance, battery conditions such as temperature, cell voltage, State of Charge (SOC), State of Health (SOH) and more.

  • Data Analysis: Offering tools to analyze system operation patterns and performance.

  • Alerts and Notifications: Informing users of any issues or maintenance needs.

  • Reporting: Generates detailed reports on system performance, maintenance activities, and operational efficiency.

  • Remote Access: Enabling control, monitoring of the system from remote locations and provides the interface to external Energy Management Systems (EMS).

A robust BESS controller is critical for ensuring safe, predictable and efficient system behavior, especially in larger multi-rack or containerized systems.

Discover: BESS (Battery Energy Storage System)


Energy Management System (EMS)

An Energy Management System (EMS) is responsible for optimizing the operation and economic performance of an ESS and overseeing the entire energy system, which may include multiple energy sources and storage devices.

Its key functions are:

  • Revenue Optimization: Maximizes revenue by participating in various ancillary services, instructing the BESS controller to charge, and discharge cycles depending on the most optimal use case.

  • Forecasting: Predicting energy production and consumption patterns to optimize energy use.

  • Integration: Coordinating between different energy sources (e.g., solar, wind) and storage systems.

 

What is Energy Storage?

Energy storage refers to the capture of energy generated at one time for use later. This process helps to balance supply and demand, stabilize the grid, and improve the efficiency and reliability of energy systems. Energy storage can be classified into several types based on the technology used:

Mechanical Energy Storage

  • Pumped Hydroelectric Storage: Uses gravitational potential energy by moving water between reservoirs at different elevations.

  • Flywheels: Store energy in the form of rotational kinetic energy, which can be rapidly released.

  • Compressed Air Energy Storage (CAES): Stores energy by compressing air, which is then released to generate electricity.


Thermal Energy Storage

  • Heat and Cold Storage: Uses materials like molten salts, concrete, or even snow to store thermal energy for later use in heating or cooling applications.

 

Chemical Energy Storage

  • Gaseous Fuels: Includes hydrogen, biogas, and methane, which can be stored and converted back into energy.

  • Solid Fuels: Includes coal, wood, and pellets, which are traditional forms of chemical energy storage.

  • Liquid Fuels: Includes oil derivatives like diesel and gasoline, as well as synthetic fuels like kerosene.

 

Electrochemical Energy Storage

  • Galvanic Cells (Batteries): Consist of two electrodes (anode and cathode) surrounded by an electrolyte and separated by a separator. Batteries are the most common form of electrochemical energy storage, used in everything from small electronic devices to large-scale grid storage systems.

Read more: Energy Storage Sysems

 

Conclusion

Energy management is a critical for energy storage systems, ensuring they operate efficiently, reliably, and sustainably. By understanding the roles of BMS, BESS Controller, and EMS, as well as the different types of energy storage, we can optimize the performance of these systems and support the transition to a more sustainable energy future.

Effective energy management enhances the performance and lifespan of energy storage systems and contributes to a more stable and efficient energy grid. As technology advances, the integration of these systems will continue to evolve, offering even greater benefits to consumers and the environment.

What is the difference between a BMS and a BESS controller? A BMS manages the battery at cell and module level, while the BESS controller oversees the entire system, including the PCS, thermal management and alarms.
Why is an EMS important? An EMS makes strategic decisions about when to charge or discharge to optimize economics, reduce energy costs and improve efficiency.
Which battery chemistry is most common today? Lithium-ion, particularly LFP, is the most widely used chemistry for stationary grid-scale applications.
What affects battery lifetime the most? Temperature control, depth of discharge, C-rate and overall energy throughput are key factors that determine degradation.
How often should ESS software be updated?

Regular updates are recommended, as they typically include performance enhancements, new features and cybersecurity improvements.

 

Are you interested in optimizing your energy storage system through effective energy management? Take a look at how our Project Excellence initiative sets you up with the tools required to make sure that your projects are in safe hands.

 

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Gustav Nyman

Gustav Nyman is CTO of Energy Storage Systems at BOS Power, with extensive international experience in product development, innovation, and business growth across industries including energy storage systems, air purification, consumer electronics, and HVAC. He has led projects and teams in Europe, Asia, and North America, delivering award-winning products and driving new business areas from concept to market. Before joining BOS Power, Gustav founded and led Nymantech AB, advised on energy storage strategy at Solkompaniet, and held senior technical and product leadership roles at REHAU, Heatex, and other global companies. He holds an MSc in Mechanical Engineering from the Faculty of Engineering at Lund University.

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