System operator’s independent report into Northland loss of electricity supply published

Transpower, in its role as system operator, has published its independent investigation into the loss of electricity supply to Northland from 20-23 June. The investigation was commissioned by Transpower as per its system operator procedures for reporting significant incidents.

The investigation focused on the operational performance of Transpower in its dual system operator and grid owner roles as well as of key industry participants leading up to and in response to the event. It did not investigate the tower failure that caused the outage, which was addressed in a separate investigation published on 1 August 2024.

The investigation concluded that Transpower and key industry participants acted appropriately and collaborated well to restore supply to the region and re-establish normal operation. No breaches of the Electricity Industry Participation Code by the system operator or any other party were identified.

Transpower was well prepared to deal with the incident in its system operator role, with the investigator noting that it had an up-to-date contingency plan developed in conjunction with the grid owner side of the organisation. The investigator found clear evidence that system operator staff were trained, ready and able to respond to the event, and that they worked well with grid owner staff and industry partners to effectively restore supply. 

All regional stakeholders were well aware of the risk of a loss of supply event in the area and together all contributed to the successful management of the event.

The report highlighted a number of areas for continuous improvement. Transpower has accepted the recommendations in full and has published its management response alongside the report. Some recommendations involve other participants, and Transpower has already initiated discussions with them about the recommendations.  

The independent report and Transpower’s response are on Transpower’s website alongside a preliminary system operator report that was published on 5 July 2024.

For further information, please contact: 

Transpower's communications team on 021 195 8613.