System Security Forecast

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The System Security Forecast (SSF) identifies risks to our ability to achieve our Principal Performance Obligations over the next three years. It provides information to enable market participants to understand security risks and how these will be managed. 

We produce the SSF every two years and provide updates every six months if there are material changes to the power system. The SSF Guidelines determine the purpose and principles of the SSF.

In addition to the SSF, we produce other security assessments that participants may find valuable. These include the Security of Supply Annual Assessment, the New Zealand Generation Balance and other updates on the market and system security such as Electricity Risk Curves. As Grid Owner, Transpower also publishes Transmission Planning Report.

Process for scoping the System Security Forecast Review

The following process was adopted in scoping the 2024 SSF and will be applied to subsequent forecasts. It provides a process for identifying and prioritising emerging issues for inclusion in the assessment.  

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2024 System Security Forecast

The risks identified for the 2024 SSF are as follows. The SSF and related documents can be found below, other documents relating to the SSF are available in the resources section of the website.

ReportContentsDate
  • N-1 Thermal, component and limits voltage Limits with Transpower’s load forecast
  • Issues associated with commissioning or decommissioning of assets connected to the Grid
  • Voltage stability risk caused by lack of generation in major load regions
  • Overvoltage management during troughs
Jul 2024
Transient Rotor Angle Stability Security (New for 2024 SSF)
  • Not yet published
Nov 2024
System Security Forecast Summary Report (New for 2024 SSF)
  • Not yet published
Dec 2024
  • A summary of the Grid configuration and general assumptions used in the SSF
Jul 2024
  • A summary of the methodology used to assess security in the SSF N-1 Thermal and Voltage Study
Jul 2024

The SSF has been refocused to assess the new and emerging security risks caused by the changing energy landscape, particularly the introduction of more inverter-based resources instead of conventional synchronous generators. The SSF will continue to study the N-1 contingency impacts to system security, but the outage (N-1-1) studies will no longer be included in the SSF as the impact of planned outages and how the System Operator studies them are captured by internal processes. The impact of outages will be studied separately and released on the Outage planning page in 2025. 

2022 System Security Forecast

The 2022 SSF will be available until the completion of the N-1-1 outage study in 2025.

2022 SSF Documents
PartNameDate
A Dec 2022
B Dec 2023
C Dec 2022
D Dec 2022
D Jun 2023
D Dec 2022
D Dec 2022
D Jun 2023
D Dec 2023
D Dec 2022
D Dec 2022
D Dec 2022
D Dec 2022
D Dec 2022
D Dec 2022
D Dec 2022
D
Part D GZ13 Otago.pdf (PDF 778.72 KB)
Jun 2023
D Dec 2022
E Dec 2022
F
Part F Dry Year.pdf (PDF 397.12 KB)
Dec 2022
G Dec 2022