Outage planning

Our aim is to keep the power on and the energy flowing but from time to time it is necessary to have an outage.

Planned outages

Planned outages are used to safely maintain our equipment or fix problems to reduce the risk of ‘unplanned’ power outages. We will first work with lines companies to route an alternative power supply and avoid consumers suffering a power cut, but this is not always possible.

Our Operations Planning Team aims to keep these to a minimum and plans any outages carefully – often over the course of 12 months – working alongside our customers (lines companies, generators, direct connects, service providers) and delivering communications to end users.

The outage schedule is published every year and is also available in the Planned Outage Coordination Process (POCP, the tool developed by Transpower and industry that is updated hourly).

Contact the Outage Planning Team to register as an Interested Participant, or for additional information.

Planned outage search

Planned outages can be searched using the Planned Outage Co-ordination Process (POCP) in the Operations Customer Portal.

Outage visualisation tool

The outage visualisation tool provides a more accessible view for market participants of the impact of planned outages that are also covered within the Planned Outage Coordination Process. Find out more

Please note you will need to register to access the outage visualisation tool.

Unplanned outages

Despite our best efforts there are often unplanned outages throughout the year – often caused by adverse weather. When we are alerted to an unplanned outage this will be listed on our home page and updates will be provided on our social media channels (Facebook).

Outage Planning Policy

Our Outage Planning Policy clarifies how, in our dual roles as system operator and owner of the national grid, we will meet our obligations around outage planning, coordination and assessment. Developed with industry participation, the Policy draws on our obligations under the Electricity Industry Participation Code (Code), particularly those which deal with the general considerations we, as grid owner, must make in planning outages, and those that are relevant to our system operator role in assessing outages and notifying interested parties. We want to be clear about our approach and how we maintain impartiality in our system operator service.

SP-OC-759 Outage planning policy.pdf (PDF 245.97 KB)

Guidelines for notifying and publishing an assessment

In some situations in the four weeks leading up to an outage, we will provide up to date information and assessments to industry participants so they can be made more aware of potential security risk and take appropriate action. This may include energy and reserve shortfalls, voltage stability violations or thermal violations.

Guidelines outline the triggers for providing an assessment to POCP and the assumptions we use in our assessments. These cover general situations but particularly two key regions of the electricity system:

Upper North Island or Zone 1 voltage stability where we will publish an assessment where the assessment shows the voltage stability margin exceeds 97.5%
The HVDC where we will publish an assessment when:
- the calculated power limit is within 50MW of the expected HVDC transfer or
- the deficit generation from NZGB for the base scenario is < 50MW (for N-1-G).
Guidelines for Notifying and Publishing an Assessment

Outage Planning Reports

As well as our usual outage communications and notifications we publish regular reports on planned transmission outages that could involve a planned a loss of supply or n-security to our connected customers.