Outage Planning

Outage Co-ordination is an essential part of managing the operation of the power system in a secure and efficient manner.

Outage Planning Policy

This policy is to clarify how, in Transpower's dual roles as system operator and owner of the national grid, we will meet our obligations around outage planning, coordination and assessment.

This policy will mean:

  • our approaches in both roles are more transparent,
  • in our system operator role we:
  1. will continue to publish assessments where there are outages that may cause a security concern
  2. will consider economic impacts of outages and the mitigation of security violations where this is relevant.

The policy is an internal policy, but one that we have published and that we have discussed with industry participants to gain their feedback.

It draws on our Code obligations, 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. These are the areas where we want to be clearer about our approach, and clearer about how we will maintain impartiality in our system operator service.

Some of our other obligations, particularly in our role as owner of the national grid are described in the Outage Protocol, which steps through how we will publish and consult on our annual outage plan, and how we will make changes to the Annual Outage Plan. This policy does not detail these types of procedural responsibilities.

SP-OC-759 Outage planning policy [ pdf 245.97 KB ]

The situations where we, as system operator, will publish assessments to POCP (Planned Outage Coordination Process)

As part of the policy, and particularly principle four, we will publish assessments, from four weeks out from outage start date, in some situations. This is to provide more up-to-date information to industry participants, so they can be made more aware of potential security risk and take appropriate action. Most situations will be when planned outages are causing an actual or perceived tighter security situation. This may include energy and reserve shortfalls, voltage stability violations or thermal violations. 

The system operators process for managing the Planned Outage Coordination Procedure, and the associated POCP Assessment templates are found below. These POCP assessments focus on four key areas of system security; Upper North Island or Zone1 (Z1) voltage stability; Upper South Island or Zone 3 (Z3) voltage stability; HVDC; New Zealand Generation Balance (NZGB) shortfalls. The process also covers other general situations for which the system operator will publish assessments.

Planned Outage Co-ordination Process

The Planned Outage Co-ordination Process (POCP) was agreed by the Planned Outage Forum in October 2002 and presented to the Grid Security Committee in November 2002.

Reviews of the POCP were completed in 2006, 2009, 2013 and 2019.

The POCP application is available on the Operations Customer Portal and hosts the outage database and a detailed User Guide.

Outage Notification Guidance

This guidance is provided to assist Asset Owners in accessing which outages or reduction in equipment capability may impact the system operator’s ability to plan to meet its Principal Performance Obligations. They have been produced in response to recommendations from the 2019 POCP review.

Contact OPS.Planner@transpower.co.nz for further assistance or specific outage queries.

Outage Disclosure Guidance [ pdf 341.98 KB ]

Attachment 1 - Minimum Outage Disclosure Requirements [ pdf 91.9 KB ]

POCP Review - Outage Notification Guidance Presentation [ pdf 474.07 KB ]

Questions and Answers

We have listed below common questions we have received from industry along with our responses.  We will continue to update this section and share with participants any updates.

Number Description

Is demand Response to be included as it is not offered in and therefore is not shown in the forward schedules?

System Operator Response 23 March 2021

At this stage demand response only needs to be disclosed to the system operator if;

  1. it meets one of the other criteria for outage disclosure, and
  2. the decision to initiate the demand response is made prior to the publication of the relevant forward schedule (i.e. more than 36 hours from real-time)

Demand response is an evolving part of the electricity system and the system operator will continue to monitor the impacts of demand response on system security.


Are Wind Farms included in the 20 MW requirement?

System Operator Response 4 March 2021

Yes they are, we have considered this question and whilst wind farm station output is usually considered to be 0MW during planning security studies for specific outages, an element of Wind farm Station output is considered in other assessments such as NZGB.

Duration of load outages that require notification i.e. >24 hrs?

System Operator Response 23 March 2021

All grid owner outages and GXP Ties that meet the disclosure guidelines require disclosure regardless of duration. All other outages require disclosure when their duration exceeds one trading period (30 minutes).


Does the load requirement apply to conforming and non-conforming loads?

System Operator Response 4 March 2021

Yes it does.