GeePower Energy Technology Co., Ltd. wishes to provide an update regarding the UK G99 certification process for its Terra A Series Battery Energy Storage System.
During the Version 2 (V2) registration process, the application was affected by updates to the G99 requirements. Although the Terra A system had previously been tested under the earlier requirements, the existing test documentation did not include the additional data required under the updated G99 standard. As a result, supplementary testing was required to complete the V2 assessment.
The ENA assessor specifically requested additional data relating to Limited Frequency Sensitive Mode – Underfrequency (LFSM-U), covering the following four test conditions:
- Test 1: 100% rated import capacity to 49.0 Hz
- Test 2: 100% rated import capacity to 48.8 Hz
- Test 3: 40% rated import capacity to 49.0 Hz
- Test 4: 40% rated import capacity to 48.8 Hz
GeePower has now completed the supplementary testing against the updated G99 requirements through Bureau Veritas. We have received the draft test report, which indicates passing results for all four test conditions.
We are currently awaiting the final test report from the testing body. Once received, it will be submitted to the ENA for review as part of the V2 registration process. The outstanding requirement identified by the ENA assessor relates specifically to the additional G99 update data outlined above.
Once the final report has been issued and the ENA review completed, GeePower will update the ENA registration and provide The 22:23 Community Interest Company with written confirmation and the relevant documentation, allowing the updated certification details to be communicated to UK Distribution Network Operators (DNOs).
We thank The 22:23 Community Interest Company and its customers for their patience and understanding while this process is being completed. GeePower remains committed to working closely with its UK partners to resolve the outstanding requirements as quickly as possible and will provide further updates as progress is made.
GeePower Energy Technology Co., Ltd.
28 October 2026