IEC 62933-5-1 specifies safety considerations for electrical energy storage (EES) systems integrated with the electrical grid, published by the International Electrotechnical Commission (IEC). It provides a systematic framework for hazard identification, risk assessment, and risk mitigation applicable to EES systems of any type or size intended for grid-integrated applications, covering both the EES system itself and its interfaces with the grid and with the site in which it is installed.
Published by: International Electrotechnical Commission (IEC)
Current edition: IEC 62933-5-1:2024 (1st edition as a full International Standard, replacing the 2017 IEC TS 62933-5-1 technical specification)
Companion standards: IEC 62933-1 (terminology), IEC 62619 (industrial Li safety), IEC 62485-5 (installation safety), NFPA 855 (US installation standard)
Scope
IEC TS 62933-5-1 applies to EES systems connected to the electrical grid, regardless of the storage technology (electrochemical, mechanical, thermal) or system size. It addresses safety at the system level, covering the EES system, its power conversion system, energy management system, and interfaces with the grid connection, site infrastructure, and environment. The standard is technology-neutral, providing a framework applicable to lithium-ion, lead-acid, flow battery, flywheel, and other EES technologies.
Key Requirements
The standard requires a systematic hazard identification and risk assessment process for the EES system, covering electrical hazards (arc flash, electric shock, DC isolation), chemical hazards (electrolyte leakage, toxic gas from thermal runaway), fire and explosion hazards, mechanical hazards, and grid interaction hazards (islanding, voltage/frequency transients). Risk mitigation measures must be identified for each significant hazard, and residual risks must be documented and communicated to operators and emergency responders.
The standard also addresses specific grid-integration safety considerations including requirements for grid disconnection under fault conditions, anti-islanding protection, and safe behaviour during grid disturbances. Requirements for the BMS safety functions, system monitoring, alarm and shutdown sequences, and emergency procedures are defined at a system level.
Relevance to Battery Engineering
IEC TS 62933-5-1 is increasingly referenced in grid operator requirements and planning consents for large-scale BESS installations. For battery system engineers, it provides the framework for developing the safety case for a grid-connected BESS project — identifying hazards, selecting mitigation measures, and documenting residual risks. The standard’s requirement for a systematic risk assessment aligns with the design process needed to comply with IEC 62485-5 installation requirements and NFPA 855 in US markets. Understanding IEC 62933-5-1 requirements enables engineers to design safety into BESS systems from the outset rather than retrofitting mitigations after a risk assessment reveals gaps.
References: IEC 62933-5-1:2024, IEC Webstore
Disclaimer: This is not a definitive guide, just an indication and it is important that you always go back to the source for legislation.
See also: IEC 62485-2