Lou: Intro: Good Day and welcome everyone to Power Bytes! I am your host Lou Signorelli and Power Bytes is your destination Podcast for power generation conversations. As always please know how much we appreciate you, our listeners. We hope you find our topics helpful and interesting. There are several ways for you to get in touch with the show. You can send us an email at powerbytes@cat.com, visit us at Cat Electric Power on Facebook or LinkedIn. Please remember to subscribe wherever you listen to our show… it really helps.
Lou: It seems energy storage is in the news nearly every day. Whether it be for electric vehicles, your home or large grid scale energy storage facilities, energy storage, or ESS as I'll refer to the large sites, is here to stay. Along with that comes risk. In the US alone there have been 5 significant fires from coast to coast in the large, grid scale sized installations (https://eridirect.com/blog/2022/03/the-5-biggest-lithium-ion-battery-fires-to-date/)
So, joining me today to speak to Energy Storage safety is Greg Hasler. Many of you will remember Greg from his appearance on Power Bytes when he talked about "Microgrids in Mining". Greg has 33 years at Caterpillar and currently serves as Chief Engineer of ePowertrain solutions in Electrification and Advanced Power Solutions here at Caterpillar.
Lou: Greg welcome back to Power Bytes!
Greg: Thank you Lou, great to be back.
Lou: So, Greg, given the fires that have popped up around the world, has there been anything done to address Fire Safety in ESS installations?
Greg: I've been involved wth ESS designs for many years. Over the last 4-5 years, the industry has started to address the risks and concerns of this rapidly developing technology. The market pull for large scale ESS was out pacing the regulatory codes and standards. Product being designed had best known systems deployed at the time but no published standards to govern the performance of the products in the event of battery system fault and subsequently a thermal runaway incident. In the US, codes and standards have been evolving quickly to address the risks to provide mitigation. In particular NFPA 855 and UL9540 are standards to address installation, design and performance concerns of ESS product.
Lou: Greg, you used two interesting words, “codes” and “standards”. Are those significantly different? Or just two ways of saying the same thing?
Greg: One way of looking at the differences between codes and standards is that a code tells you what you need to do, and a standard tells you how to do it.
Lou: That's great, sounds like the Codes and Standards are catching up with the industry. What can you tell us about NFPA 855 that our facility owners and operators should know?
Greg: NFPA855 2020 Standard for the Installation of Stationary Energy Storage Systems first edition was issued Aug 5, 2019 and just updated to release NFPA855 2023 in September of 2022. This standard provides the minimum requirements for mitigating the hazards associated with ESS and the storage of lithium metal or lithium-ion batteries.
Lou: What are some of the key elements we need to know about in NFPA855?
Greg: NFPA855 is a standard for how to install an ESS and gives guidance to the Authorities Having Jurisdiction (AHJs). If a product does not have a Product Safety Standard Listing for compliance, NFPA855 is a document the AHJ can follow to ensure the product is designed with Safety in mind for installation at a particular customer site.
Lou: Greg I understand that there is a UL counterpart as well, is it UL9540 and 9540A?
Greg: UL9540 is a product safety standard which incorporates all aspects of the ESS solution. Primary safety standard contributors are UL1973 for the battery system and UL1741 for the power conversion system, I.e. BDP product. In order to obtain a Listing with UL, all components that comprise the ESS solution are evaluated to safety standards, HVAC, wiring, paint, door seals, etc.... Very comprehensive product review for safety compliance.
UL 9540A is a Standard for Safety which is a Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems. This test standard was developed to address safety concerns identified in the building codes and the fire service in the United States. One of the primary concerns that NFPA 855 and the International Fire Code (IFC) tries to address is the potential fire and explosion hazards associated with a battery energy storage system (BESS). The test methodology in UL 9540A determines the capability of a battery technology to undergo thermal runaway and then evaluates the fire and explosion hazard characteristics of those battery energy storage systems that have demonstrated a capability to undergo thermal runaway. The data generated from the UL 9540A test can be used to address requirements in the fire and other codes that require energy storage systems to meet certain location limitations, separation distances, fire suppression and other criteria. The 4th edition of UL 9540A is the most current.
A common miss understanding from specifiers is requesting certification to UL9540A. UL9540A is the procedure to characterize an energy storage product for thermal runaway and propagation to subsequent equipment. UL9540A is the means and method to collect data, there is no pass or fail criteria, only performance criteria that dictates the levels of testing that is required. The UL9540A test results feed into or support UL9540 2nd Edition Listing criteria and NFPA855 Standard guidance for installation of ESS products.
Lou: What is the relationship between the UL and NFPA standards?
Greg: One way to look at NFPA vs. UL, NFPA are the regulatory codes and standards in the United States that AHJs use in the field to assure equipment is designed and installed for safe operation. UL is a Nationally Recognized Test Laboratory (NRTL) which writes product safety standards and performs compliance validation to regulatory codes and standards. After a product is reviewed by UL for the applicable standards, UL provides an Authorization to Mark and a Listing of the product showing the product meets the necessary aspects from a given standard.
Having a UL Listed product stream lines the installation process in the field with AHJs.
Lou: Well, there you have it folks. I'd like to thank Greg Hasler for sharing his expertise with us today and as always, thank you for joining us today on Power Bytes. Remember to like, share, follow, and comment on all the episodes that you listen to. It really helps! Be sure to check Cat Electric Power on Facebook or LinkedIn. Till next time, thanks for listening to Power Bytes.