IEC TS 62933-2-3:2025

Electric Energy Storage (EES) Systems - Part 2-3: Unit parameters and testing methods - Performance assessment test during site operation

IEC TS 62933-2-3:2025 specifies the unit parameters and testing methods that validate and assess the performance of EES systems after commissioning.

General Information

• Status: Published
• Publication Date: 14-May-2025
• ICS: 13.020.30 - Environmental impact assessment
• Technical Committee: TC 120 - Electrical Energy Storage (EES) systems
• Drafting Committee: WG 2 - TC 120/WG 2
• Current Stage: PPUB - Publication issued
• Start Date: 15-May-2025
• Completion Date: 11-Apr-2025

Standards Content (Sample)

IEC TS 62933-2-3 ®
Edition 1.0 2025-05
TECHNICAL
SPECIFICATION
Electric Energy Storage (EES) Systems –
Part 2-3: Unit parameters and testing methods – Performance assessment test
during site operation
ICS 13.020.30  ISBN 978-2-8327-0392-2

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– 2 – IEC TS 62933-2-3:2025 © IEC 2025
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, abbreviated terms and symbols . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 7
3.3 Symbols . 7
4 General requirements of the operational performance testing . 9
4.1 Purpose . 9
4.2 Stakeholders . 10
4.3 Principles of assessment intervals and data sampling . 10
4.4 Data requirements . 10
4.5 Operational performance testing methods . 11
5 Operational performance testing items . 12
5.1 General . 12
5.2 General operational performance testing items . 12
5.2.1 Actual energy storage capacity . 12
5.2.2 Input and output power rating . 12
5.2.3 Roundtrip efficiency . 12
5.2.4 Auxiliary power consumption . 12
5.3 Energy-related operational performance testing items . 12
5.3.1 Available hours of an EES system . 12
5.3.2 Equivalent operation factor of an EES system . 12
5.4 Efficiency-related operational performance testing items . 13
5.4.1 Comprehensive efficiency of an EES system . 13
5.4.2 Energy loss rate of an EES system . 13
5.4.3 Duty cycle roundtrip efficiency . 13
5.5 Reliability-related operational performance testing items. 13
5.5.1 Planned outage factor of an EES system . 13
5.5.2 Unplanned outage factor of an EES system . 13
5.5.3 Availability factor of an EES system . 13
5.6 Grid-connected operational performance testing items . 13
5.6.1 Impact of grid conditions on the performance . 13
5.6.2 Active power control test. 14
5.6.3 Reactive power control test. 14
5.6.4 Primary frequency regulation test . 14
5.6.5 Secondary frequency regulation test . 14
5.6.6 Grid-connected operation power quality test . 14
5.7 Operational performance testing items in specific applications . 15
5.7.1 Classification and summary of EES system applications . 15
5.7.2 Frequency regulation mode . 15
5.7.3 Fluctuation reduction mode . 15
5.7.4 Reactive power voltage control mode . 15
5.7.5 Power quality management mode . 15
5.7.6 Peak shaving/peak shifting mode . 16
5.7.7 Renewable firming mode . 16
5.7.8 Islanded grid mode . 16

5.7.9 Backup power mode . 16
6 Operational performance testing methods of EES systems . 16
6.1 General . 16
6.2 General operational performance testing method . 17
6.2.1 Genaral . 17
6.2.2 Actual energy storage capacity . 18
6.2.3 Input and output power rating . 18
6.2.4 Roundtrip efficiency . 18
6.2.5 Auxiliary power consumption . 19
6.3 Energy-related operational performance testing method . 20
6.3.1 General . 20
6.3.2 Available hours of an EES system . 20
6.3.3 Equivalent operation factor of an EES system . 21
6.4 Efficiency-related operational performance testing method . 22
6.4.1 General . 22
6.4.2 Comprehensive efficiency of an EES system . 22
6.4.3 Energy loss rate of an EES system . 23
6.4.4 Duty cycle roundtrip efficiency . 24
6.5 Reliability-related operational performance testing method . 25
6.5.1 General . 25
6.5.2 Planned outage factor of an EES system . 25
6.5.3 Unplanned outage factor of an EES system . 25
6.5.4 Availability factor of an EES system . 25
6.6 Grid-connected operational performance testing method . 26
6.6.1 General . 26
6.6.2 Active power control test. 26
6.6.3 Reactive power control test. 28
6.6.4 Primary frequency control . 30
6.6.5 Secondary frequency control . 32
6.6.6 Grid-connected operation power quality test . 32
6.7 Operational performance testing method in specific application . 32
6.7.1 Genaral . 32
6.7.2 Frequency regulation mode . 33
6.7.3 Fluctuation reduction mode . 33
6.7.4 Reactive power voltage control mode . 34
6.7.5 Power quality management mode . 34
6.7.6 Peak shaving/peak shifting mode . 34
6.7.7 Renewable firming mode . 35
6.7.8 Islanded grid mode . 36
6.7.9 Backup power mode . 36
Annex A (informative) performance indicators of primary concern to major
stakeholders . 37
Bibliography . 39

Figure 1 – Example of classification of EES systems . 10
Figure 2 – The prioritization and test procedures of the test methods . 11
Figure 3 – EES system architecture with one POC type . 17
Figure 4 – EES system architecture with two POC types . 17

– 4 – IEC TS 62933-2-3:2025 © IEC 2025
Figure 5 – Example of active power test curve in charging state of an EES system . 27
Figure 6 – Active power control response time of an EES system . 28

Table 1 – Example of typical and not exclusive applications classification . 15
Table 2 – Qualified frequency range of islanded mode . 36
Table A.1 – Performance indicators of primary concern to major stakeholders . 37

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL ENERGY STORAGE (EES) SYSTEMS –

Part 2-3: Unit parameters and testing methods –
Performance assessment tests during site operation

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other act
...