4 February 2020 under-frequency event

The system operator recommended that the causer of the 4 February 2020 under‑frequency event was Genesis Energy Limited as the generator that owns Huntly Unit 4. Our draft determinations agree with the system operator’s recommendations.

We did not receive any submissions on the draft determination for the 4 February 2020 UFE.

Our final determination, under clause 8.61 of the Code, is that Genesis was the causer of the under-frequency event on 4 February 2020 at 11:33 pm.

Our reasons for this final determination are:

• a UFE occurred on 4 February 2020 at 22.33 hours when frequency dropped to 49.20 Hz in the North 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, and
• the system operator and Genesis agree that Genesis was the causer of the UFE.

In accordance with clause 8.65 of the Code, the clearing manager will rebate the event charge to relevant participants. The charge advised in the system operator's report to the Electricity Authority is $153,125.