Battery Energy Storage Systems (BESS) are growing with the deployment of renewables. Solar and wind generation can be variable, posing challenges to grid operators and their needs for grid stability, reliability, and flexibility. Storage technology may help provide solutions to grid challenges as more solar and wind generation is integrated into the grid. 

However, running a successful BESS project isn’t as simple as picking out the best battery technology to meet your needs. Most projects also need to comply with relevant certification, grid- integration, fire-safety, building-code and procurement requirements.

What Qualifications Do BESS Projects Require? 

Technology, power and energy-capacity, grid integration needs, fire-safety and building-code compliance are just some of the requirements BESS projects need to consider. Individual requirements may vary by size of system, application, location, and whether the project is residential, commercial and industrial (C&I), or utility-scale.

UL Standard for System Certification: UL 95 40

UL 95 40 covers the entire energy storage system, rather than focusing on an individual battery cell or component. For BESS developers and owners, understanding how system certification works is key when picking equipment and preparing to install and approve a system.

UL 9540 vs UL 95 40A 

UL 9540 and UL 95 40A are often misunderstood and incorrectly used as if they are the same requirement. However, they serve two different purposes. UL 95 40 is a system-level safety standard for energy storage systems. UL 95 40a is a test method that determines how battery energy storage systems behave during thermal runaway and whether fires will propagate.

For BESS projects, this difference is critical. UL 95 40 can provide needed system certification, while UL 95 40a provides testing data that could help support a project’s fire-safety evaluation and code compliance. Both UL standards could play a role in properly developing and approving a BESS project.

IEC Standards for Grid Integration and Performance

For BESS applications, the difference matters. UL 95 40 can help offer a needed system certification. UL 95 40a offers testing data that may be able to support a project’s fire-safety analysis and code compliance. Both UL standards may have a role in properly scoping and approving a BESS project.

IEC Standards for Grid Integration and Performance 

Another group of standards BESS projects should consider are applicable IEC standards for grid integration and system performance. These standards help determine how an energy storage system interacts with the grid and how it performs under load.

The specific IEC standards that apply to a C&I BESS project will vary by system design, application, equipment use and jurisdiction. Determining which standards apply should take place during the engineering phase of the project, not during installation or commissioning.

Where Are Fire-Safety Codes Located? 

Fire safety is another key topic for BESS projects. NFPA 855 is the leading fire code most associated with BESS. It outlines how stationary energy storage systems should be installed.

NFPA 855 can apply to BESS installations that are located in many different situations. For example, the code applies to some installations that are outdoors in containers. An outdoor BESS installation does not necessarily mean the project is exempt from fire codes. NFPA 855 has a number of provisions for outdoor installations and it ultimately comes down to what the authority requires for your project.

BESS projects may also fall under provisions in the International Building Code (IBC). Building codes can play a role in where an energy storage system can be located. They can also impact the construction and fire safety criteria for the BESS equipment.

Which Certifications Matter During Procurement? 

Consider certifications before purchasing any equipment. Procurement should know what certifications and standards apply to the BESS technology being procured as well as the location of the project.

• UL 95 40, applicable IEC standards, and fire-code requirements can impact which equipment gets selected.
•  Fire-safety requirements can influence the system’s location, configuration, spacing, enclosure, and other design decisions.

Early consideration allows developers to identify potential compliance issues before procurement and installation. This can make the approval process more predictable and reduce the risk of costly changes later.

Start with the system database at bessbase.com to filter BESS products by chemistry and duration, then map each shortlisted system’s available test documentation against the requirements above before issuing an RFP. That sequence keeps procurement aligned with the compliance path from the start.

Combining Compliance With the Project Lifecycle

BESS compliance works best when it is treated as a continuous part of the project lifecycle. During the early design stage, developers should identify applicable certification, grid-integration, building, and fire-safety requirements. During procurement, equipment should be selected based on both technical performance and compliance needs. During installation and commissioning, the project should be reviewed against the requirements applicable to its specific location and configuration.

References

1. UL Solutions. “UL 9540: Energy Storage Systems and Equipment.” shopulstandards.com

1. UL Solutions. “UL 9540A: Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems.” shopulstandards.com

1. National Fire Protection Association (NFPA). “NFPA 855: Standard for the Installation of Stationary Energy Storage Systems.” nfpa.org

1. International Electrotechnical Commission (IEC). “IEC 62619:2022 – Secondary Cells and Batteries Containing Alkaline or Other Non-Acid Electrolytes.” webstore.iec.ch

1. IEC. “IEC62933 Series – Electrical Energy Storage (EES) Systems.” webstore.iec.ch