11 April 2024 under-frequency event

The Electricity Authority's final determination is that Genesis Energy Limited, as the generator that owns Huntly Unit 4, was the causer of the 11 April 2024 under-frequency event (UFE).

The Authority's reasons for this final determination are:

• A UFE occurred at 12.25am on 11 April 2024 when frequency dropped to 49.17Hz in the North Island and 49.25Hz in the South Island
• The interruption/reduction of electricity occurred at the grid injection point for Huntly Unit 4, 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 UFE
• 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 $205,003.75.

Any dispute of this final determination can be lodged with the Rulings Panel via registrar@electricityrulingspanel.nz by 5pm, 17 December 2024.

This consultation sought feedback from generators, the grid owner and other participants who may be substantially affected by the Authority’s draft determination that Genesis Energy Limited, as the generator which owns Huntly Unit 4, was the causer of the under-frequency event at 12:25am on 11 April 2024.

Under the Electricity Industry Participation Code, the Electricity Authority is required to consult with every generator, grid owner and other participant substantially affected by an under-frequency event about a draft determination.

No submissions were received on this consultation.