Decision on 24 January 2023 under-frequency event

In September 2023, the Electricity Authority consulted on its draft determination for an under-frequency event on 24 January 2023.

Our final determination under clause 8.61 of the Electricity Industry Participation Code is that Genesis Energy Limited (Genesis), as the generator that owns Huntly Unit 5, was the causer of the under-frequency event (UFE) on 24 January 2023 at 3:49pm.

Our reasons for the determination are:

• A UFE occurred on 24 January 2023 at 3:49pm when frequency dropped to 48.98Hz in the North Island and 49.13Hz in the South Island.
• The interruption/reduction of electricity occurred at the grid injection point for Huntly Unit 5, which belongs to Genesis.
• No other asset was identified as having caused or potentially caused the UFE.
• The system operator and Genesis agree that Genesis was the causer of the UFE.

The charge advised in the system operator's reports to the Authority was $397,118.75 for 24 January 2023. In accordance with clause 8.65 of the Code, the clearing manager will identify the relevant participants affected and the portion of the charges payable to each.

If a substantially affected participant would like to dispute this final determination, they can provide a written notice to the Rulings Panel within 10 business days after the publication of this decision.

Notices should be sent to registrar@electricityrulingspanel.nz by 5pm on 12 March 2024.

View 24 January 2023 under-frequency event