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UL Certification for Energy Storage Equipment Subassemblies Helps Shorten Path to Energy Storage Systems Compliance

UL certifies three energy storage equipment subassemblies for NHOA.

White energy storage units

March 8, 2022

NORTHBROOK, Illinois – March 8, 2022 – UL, a global safety science leader, announced today that it has created a certification service for energy storage equipment subassemblies (ESES) to evaluate for compliance to UL 9540, the Standard for Energy Storage Systems and Equipment. This allows manufacturers of large energy storage assets to procure certified (listed) components from the battery supplier and the power conditioning equipment supplier to create the energy storage system (ESS).

UL certified three ESES for NHOA Energy (formerly Engie EPS), NHOA Group’s Global Business Line dedicated to stationary energy storage that designs and delivers turn-key storage systems, helping independent power producers to achieve their renewable targets.

The ESES Certification program makes it easier for direct current (DC) storage system manufacturers, code authorities and owners of ESS assets to:

  • Demonstrate DC storage systems meet UL 9540

  • Have flexibility when pursuing UL’s Battery and Energy Storage System Testing and Certification services

  • Find suppliers within UL Product iQ®

  • Navigate a rapidly changing code and regulatory compliance environment

“Through the new Energy Storage Equipment Subassemblies Certification, a DC storage system manufacturer has an easier and faster path toward Certification to UL 9540. This is another example of how our cost-effective and time-sensitive certification strategies deliver the utmost flexibility and superior certification methods, accelerating time to market,” said Maurice H. Johnson, a product manager for batteries and energy storage systems in UL’s Energy and Industrial Automation group. “UL is first to offer this type of Certification, and we are proud that we can pair it with our world-class fire propagation testing.”

UL established the market-leading testing and certification offerings for ESS, contributing to the simplification of complex certification activities and empowering customers to effectively navigate rapidly evolving code and regulatory changes. UL’s global network of expert engineers can translate and support the various requirements for a specific market application.

L. Costanza, head of Certification and Quality at NHOA added, “Having the first system to achieve the UL Certification to UL 9540 for NHOA’s ESES reflects our commitment to complying with the latest safety standards and our focus on the U.S. energy storage market. This result allowed the installation of NHOA high-density 40-foot containers in two utility-scale storage systems in California and Massachusetts. With the UL Certification for ESES process, NHOA can now provide safer and more competitive solutions.”

About UL
UL is a global safety science leader. We deliver testing, inspection and certification (TIC), training and advisory services, risk management solutions and essential business insights to help our customers, based in more than 100 countries, achieve their safety, security and sustainability goals. We believe our deep knowledge of products and intelligence across supply chains make us the partner of choice for customers with complex challenges. Discover more at

Press contact:

Steven Brewster