By LaTanya Schwalb, Principal Engineer, UL Solutions

As the world accelerates toward a cleaner and more sustainable energy future, battery energy storage systems (BESS) have emerged as a cornerstone of the energy transition. These systems bridge the gap between renewable energy generation sources and the increasing demand for consistent electricity, enabling the shift to resilient, decentralized power grids.

Energy storage is rapidly growing in importance, with U.S. electricity demand projected to increase by more than 50% by 2050, according to the National Electrical Manufacturers Association’s (NEMA) forthcoming Grid Resiliency Study. As renewable energy sources become more prominent, their ability to store and deploy energy when needed helps ensure a stable, flexible and sustainable energy supply for industries, communities and individuals alike.

To enable the safer and more reliable deployment of BESS, UL Standards & Engagement has developed a suite of UL Standards that will help manufacturers demonstrate their products’ compliance with rigorous energy storage system (ESS) requirements as they scale:

• UL 9540, the Standard for Energy Storage Systems and Equipment, is the nationally adopted safety Standard for energy storage systems and equipment.
• UL 9540A, the Standard for Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems, is the nationally adopted test methodology for evaluating fire and explosion characteristics of ESS capable of thermal runaway fire propagation, helping manufacturers ensure that they comply with evolving safety regulations.
• UL 1973, the Standard for Batteries for Use in Stationary and Motive Auxiliary Power Applications, is the nationally adopted safety Standard that focuses on battery systems for use in ESS, light electric rail (LER) and stationary rail, and vehicle auxiliary power applications.
• UL 1974, the Standard for Evaluation for Repurposing or Remanufacturing Batteries, is the nationally adopted safety Standard that evaluates the sorting and grading processes of facilities that repurpose or remanufacture batteries.

In addition, NEMA has introduced its BESS Testing and Performance Measurements standard. This standard establishes consistent methods for evaluating ESS performance, enabling manufacturers and end users to make informed comparisons and decisions. NEMA’s standard is particularly critical for data centers, which are expected to see electricity demand double or triple by 2030 due to the rise of artificial intelligence, supercomputing and cloud technologies.

The development and commercial availability of battery technologies and chemistries such as solid-state, sodium-ion or flow batteries, to name a few, are driving sustainability and innovation. Portable and mobile energy systems are also emerging, highlighting the versatility of energy storage across diverse applications.

From microgrid-powered subdivisions to hospitals and schools that remain operational during outages, energy storage is empowering communities to embrace cleaner, more sustainable energy solutions. These systems reduce reliance on traditional grid infrastructure and strengthen resilience in the face of extreme weather.

BESS are more than a technological solution; they are the foundation of the energy transition, enabling the integration of renewable energy into resilient, decentralized grids. By addressing safety, performance and sustainability, UL Solutions and our partners at NEMA are equipping industries and communities with the tools needed to power a cleaner, electrified future. Together, we are shaping an energy landscape that supports safety, reliability and flexibility for generations to come.