Our projects
Monitoring, compliance and enforcement

Under-frequency event determinations

As the regulator of the New Zealand’s electricity industry, we are required to investigate under‑frequency events and allocate event charges accordingly.

Overview

When an under‑frequency event happens, it is our job to determine who caused the under-frequency event in order to allocate charges to the causers.

We consult on our draft determinations of the event causers, then consider submissions before publishing our final determinations.

Timeline

Past activity

Project background

An under-frequency event (UFE) is an interruption or reduction of electricity into the electricity grid, or an interruption or reduction of electricity injected from the HVDC link into the South Island HVDC injection point or the North Island HVDC injection point.

A UFE is caused by an interruption or reduction of electricity from one or more generators of electricity, or an interruption somewhere in the transmission of electricity. The causer of an under-frequency event is either an electricity generator (like Genesis, Mercury or Meridian) or a grid owner (like Transpower).

UFEs need to be avoided because the system needs to keep frequency levels stable across connect systems. Unstable frequencies can damage equipment and can have serious implications when providing electricity at a national scale.

Other projects in Monitoring, compliance and enforcement
View all projects

System operation documents

The system operator regularly reviews their plans, strategies, and policy.

View project
Closed

Improving the information gathering framework

Enhancing the framework in the Code for information gathering.

Have your say

Submissions open until 5 September 2025

View consultation
Closed

Electricity Allocation Factor

Determinations of the Electricity Allocation Factor under the Climate Change Response Act 2002.

View project