Response to 9 August 2021 Grid Emergency

On 9 Aug 2021 the country faced the largest demand peak in response to one of the coldest nights of the year. As system operator, we called a Grid Emergency when insufficient generation was available to meet demand, leading to some customers being disconnected. A number of reviews of this event are underway including an independent review commissioned by Transpower to help us understand the event and industry’s response on the night, to identify where we need to make changes. As system operator, we have a programme of work underway to address recommendations from each of the reports, which includes industry engagement.

Event reviews 

Date Description Link
27 Apr 2022

Electricity Authority, Phase 2 Demand Management Event Report

12 Oct 2021 Transpower-commissioned review, PBA Consulting Independent Investigation Report [ pdf 2.19 MB ]
12 Oct 2021 Transpower-commissioned review, Thompson Lewis Independent Investigation ­‑ Stakeholder Communications Report [ pdf 178.12 KB ]
24 Sep 2021 Transpower response to immediate assurance review (letter and attachment)



10 Sep 2021 Electricity Authority, Phase 1 Immediate Assurance Review Report
25 November 2021 Ministry of Business Innovation and Employment Review Report

Revision of notices for insufficient generation

Following industry feedback we published our revised process and operational notices for insufficient generation on 30 November 2022. This is available here.

We are also in the process of consulting more generally on the notices we send to industry and how these could be improved. It’s really important that everyone gets involved in this important work to make sure that the right information is getting to the right people at the right time so that we can continue to deliver the reliable electricity services that New Zealanders have come to expect. This is an ongoing process as we are looking to continuously improve so please get in touch at if you haven’t already provided your views.

Industry exercise to simulate a generation shortfall

We are running a simulation exercise on May 26 to test the industry’s response to a generation shortfall event like the one that occurred on August 9. Exercise Shortfall is designed to test improved communications and operational processes put in place since then and look for further opportunities for improvement. 

The exercise assumes that no additional generation is possible. Therefore, we have invited lines companies and direct connect customers to take part in the exercise and extended an invitation to all other industry participants and stakeholders to observe. There is also an opportunity for retailers to work with their local lines company on the side lines of the exercise to understand how they will implement demand management during a generation shortfall as well as how they would work with lines companies to keep electricity end users informed (including medically dependent consumers).

More information is available here.

Industry briefings and presentations

On 30 November the System Operator held an update on its work to update its processes and notices.

PDF of presentation of 30 November Briefing  [ pdf 1018.17 KB ]

On 20 October 2021, the System Operator held a sector briefing on follow up actions on the events of 9 August 2021.

20 Oct sector briefing on 9 Aug actions PDF for website.pdf [ pdf 1.37 MB ]