IEC 62933-3-1:2025

Overview

IEC 62933-3-1:2025 - Electrical energy storage (EES) systems - Part 3‑1: Planning and performance assessment of electrical energy storage systems - General specification - is a comprehensive international standard for planning, designing, testing and assessing grid‑connected EES systems for indoor or outdoor installation. It defines required functions and capabilities, sizing and design processes, operational and monitoring requirements, control and information‑exchange needs, testing (FAT/SAT) and maintenance, plus lifecycle and decommissioning considerations.

Key topics and technical requirements

• Scope and system architecture - classification of EES subsystems (accumulation, power conversion, auxiliary and control subsystems) and typical architectures for grid connection.
• Main electrical parameters - guidance on specifying active/reactive power ratings, rated energy storage capacity, response time, auxiliary power, self‑discharge, round‑trip and duty‑cycle efficiencies, recovery time and lifetime metrics.
• Sizing and design process - step‑wise planning flow covering preliminary and final sizing, duty cycle definition at the point of common coupling (POC), environmental and grid constraints, and design trade‑offs.
• Control and communications - functional requirements for control subsystem operations, operation states, control strategies (e.g., P(f)), and the information model for remote monitoring and control.
• Performance testing and acceptance - requirements for Factory Acceptance Test (FAT), Installation and Commissioning, and Site Acceptance Test (SAT); methods for performance assessment and performance‑monitoring during service life.
• Operational requirements and maintenance - monitoring, data acquisition, availability expectations, maintenance planning and repair time considerations that affect asset availability.
• Lifecycle and decommissioning - guidance on end‑of‑service planning, inspection, recycling and safe dismantling.

Practical applications

IEC 62933-3-1:2025 is directly applicable to planning and assessing EES used for:

• Grid support and voltage/reactive power control
• Frequency control (primary, secondary, dynamic)
• Renewable energy firming and smoothing (PV/wind integration)
• Electric vehicle charging station energy buffering
• Backup power and black‑start support
• Multi‑function commercial and utility energy storage projects

The standard includes annex examples (duty cycles, operation patterns and application scenarios) that help translate planning requirements into real‑world project specifications.

Who should use this standard

• Power system and EES planners
• Grid and EES owners and operators
• Constructors and suppliers of EES equipment
• Aggregators and project developers
• Commissioning, testing and maintenance teams

Related standards and compliance

Use IEC 62933-3-1 alongside other parts of the IEC 62933 series, applicable national grid codes, safety and environmental regulations, and equipment‑specific standards for batteries, converters and protection systems to ensure full regulatory and technical compliance.