CLC/SR 120 - Electrical Energy Storage (EES) Systems

IEC 62933-1:2024 defines terms applicable to electrical energy storage (EES) systems including terms necessary for the definition of unit parameters, test methods, planning, installation, operation, environmental and safety issues. This terminology document is applicable to grid-connected systems able to extract electrical energy from an electric power system, store energy internally, and provide electrical energy to an electric power system. The step for charging and discharging an EES system can comprise an energy conversion. This second edition cancels and replaces the first edition published in 2018. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) addition (with revision) of the entries developed during the edition 1 stability period and, therefore, included only in other IEC 62933 parts; b) addition of the entries developed during the edition 1 stability period and published in this document for the first time; c) complete revision of the entries already present in edition 1.

IEC 62933-1:2018 defines terms applicable to electrical energy storage (EES) systems including terms necessary for the definition of unit parameters, test methods, planning, installation, safety and environmental issues. This terminology document is applicable to grid-connected systems able to extract electrical energy from an electric power system, store it internally, and inject electrical power to an electric power system. The step for charging and discharging an EES system may comprise an energy conversion.

IEC 62933-2-1:2017 focuses on unit parameters and testing methods of EES systems. The energy storage devices and technologies are outside the scope of this document. This document deals with EES system performance defining:  
unit parameters,
testing methods.

IEC 62933-5-2:2020 primarily describes safety aspects for people and, where appropriate, safety matters related to the surroundings and living beings for grid-connected energy storage systems where an electrochemical storage subsystem is used.

IEC 62933-5-1:2024 specifies safety considerations (e.g. hazards identification, risk assessment, risk mitigation) applicable to EES systems integrated with the electrical grid. This document provides criteria to enable the safe application and use of electrical energy storage systems of any type or size intended for grid-integrated applications. This document can be applied to all EESS technologies, but for requirements specific to electrochemical EES systems, reference is also made to IEC 62933-5-2. This first edition cancels and replaces the first edition of IEC TS 62933-5-1 published in 2017. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC TS 62933‑5‑1:2017: a) Revising “should” statements to “shall” statements for all requirements and move some “should” statements clauses to Annex B for informative purposes. b) Update standard references (normative). c) Update definitions and add or remove definitions where necessary. d) Revise criteria in Clause 6 and Clause 7 to be actionable and add standard references where necessary. e) Revise Clause 8 for more thorough test method and criteria, add tests where necessary. f) Add markings and instruction criteria. g) Revise Annex A to add technology safety information on gravitational and thermal EESS. h) Add Annex B and Annex C for safety considerations for EESS and test method for mechanical EESS. i) Add informative list of standards and update bibliography.

IEC 62933-4-4:2023 describes environmental issues when reused batteries are considered for a BESS. It provides details and requirements for identifying and preventing environmental issues in each life cycle stage, i.e., from the design to the disassembly of such reused batteries in a BESS.

IEC 62933-5-3:2023 applies to those instances when a BESS undergoes unplanned modifications. Such modifications can involve one or more of the following: - changes in energy storage capacity; - changes of chemistries, design and manufacturer of the accumulation subsystem; - changes of a subsystem component using non-OEM parts, - changes to the mode of operation, - changes of the installation site, or - changes in an accumulation subsystem due to an installation of reused or repurposed batteries. Any such modification can impair the original state of safety of the BESS. This document complements IEC 62933-5-2, which relates to the overall safety aspects of a BESS. The requirements covered by this document are applied in addition to the requirements in IEC 62933-5-2 in accordance with each situation.