Operational Information

Power system operational data is published in this section.


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As the System Operator, we distribute operational notices to registered participants of the electricity market.

When we have low supply margins for forecast demand, we endeavour to notify the market via a CAN. This notice is triggered when there is 200MW or less of residual energy left to meet demand & reserves
Excursion Notices are issued when a voltage or frequency disturbance occurs on the power system.
Formal Notices inform participants informing of events happening on the power system that require parties to take some action.

Published Data

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We publish this data on a 'best endeavours' basis. We take no responsibility for the actions taken by any party based on this information.

This displays energy supply and generation information for the previous week.
Power system data is displayed by fuel type.
Tracks renewable energy on the power system over the last week, month and year.
Daily updates of HVDC flows modelled by our Scheduling Pricing and Dispatch solutions.
We are producing monthly reports on low frequency dynamic oscillatory stability of the power system. These are produced and  analysed using phasor measurement unit data.
View load information graphically on the New Zealand power system aggregated by our operational zones.
Shows the load values for each of these zones over the last 30 minutes.
Power system loads in the North Island north of Huntly (Zone 1) are displayed on this page to give power companies loading information across the zone.
Power system loads in the South Island north of Waitaki Valley (Zone 3) are displayed on this page to give power companies loading information across the zone.

Security Management

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We implement security policies as defined in Transpower’s connection contract.

A coordinated outage process is used by asset owners to help with the co-ordination of planned equipment outages. The process uses a database in which all asset owners enter planned outage details.
In accordance with our obligations under the Security Policy of the Policy Statement, we categorise events according to the way we prepare and manage them.
Manual Load Shedding is the final step in a process that begins with us communicating with the distributors regarding a Grid Emergency and the likely demand reductions required.
As system operator we use Remedial Action Schemes (RAS) to model special protection schemes to manage the transmission system with improved accuracy and improved security.
Special Protection Schemes are means by which circuit loadings, voltage or frequency can be controlled after an event on the power system which might otherwise cause an overload of equipment.