Samsung SDI's energy storage system (ESS) has succesfully completed a test developed by global safety certification company UL that certifies the system's ability to prevent large-scale fires.

The lithium-ion battery manufacture said it was the first company in the world to fulfill the rack-level safety standards of the UL9540A test.

The UL 9540A "Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems" has been developed to help manufacturers have a means of proving compliance to the new regulations.

UL 9540A was developed to address safety concerns identified by the building codes and the fire service in the United States. The current ICC International Fire Code (2018 IFC) allows an individual battery energy storage system (BESS) unit not exceeding 50 kWh and having a maximum quantity of systems totaling 600 kWh of energy per indoor fire area (battery room). The 2018 IFC and the draft NFPA 855 standard for installation of energy storage systems currently limits the individual BESS unit size for UL 9540 listed units to 250 kWh. These BESS units are to be installed with separation distances of 3 feet (1 meter) between units and between units and any wall. The latest IFC and NFPA 855 drafts allow the code official (AHJ) to approve larger individual BESS units, and separation distances less than 3 feet based on large scale fire testing conducted in accordance with the UL 9540A Test Method.

The results from the UL 9540A Test Method addresses the following key issues identified by building codes and the fire service:

• BESS installation instructions
• Installation ventilation requirements
• Effectiveness of fire protection (integral or external)
• Fire service strategy and tactics

In short, the test evaluates cell, module, rack and system-level safety, measuring the characteristics of thermal runaway, and the amount and composition of gas during such an event. The test results are utilized to define mitigation strategies against ESS fires or explosions.

The racks that satisfy the test standards can be installed without a separate fire-fighting system.

"We were able to satisfy the UL9540A test for the first time in the industry, based on our efforts to put safety first," said Seo Kyung-hoon, a vice president in the Samsung SDI marketing team. "We are committed to developing the best-in-class, market-leading ESS safety technology."

After several ESS fires over the past few years, Samsung SDI has been taking steps to prevent them in a bid to restore confidence in the ESS industry here.

The company has also developed a set of safety measures, including the application of a special fire extinguishing system.