Causer of 27 June 2024 under-frequency event determined

Following consultation, we have decided that Genesis Energy Limited, as the generator that owns Huntly Unit 1, was the causer of the 27 June 2024 under-frequency event.

The Authority's reasons for the determination are:

• An under-frequency event occurred at 12.32am on 27 June 2024 when frequency dropped to 49.21Hz in the North Island
• The interruption/reduction of electricity occurred at the grid injection point for Huntly Unit 1, which belongs to Genesis
• No other asset was identified as having caused or potentially caused the UFE
• Genesis agreed with the system operator’s assessment that Genesis was the causer of the under-frequency event
• The Authority did not receive any feedback that disputed its draft determination.

In accordance with clause 8.65 of the Electricity Industry Participant Code, the clearing manager will rebate the event charges to the relevant participants. The event charge calculated in the system operator’s report to the Authority is $220,550.00.

Any dispute of this final determination can be lodged with the Rulings Panel by 5pm on 10 January 2025.

About 27 June 2024 under-frequency event