Background

In addition to the continuous transfer of power in either direction, Basslink is designed to operate with a dynamic transfer capacity from Tasmania to Victoria of up to 630 MW (or 594MW at the receiving end) for short periods of time. Since Basslink was acquired by APA Group in October 2022, this additional dynamic transfer capacity has not been available to the market pending installation and commissioning of a new Cable Load Prediction System (CLPS). The purpose of the CLPS is to make the dynamic capacity available without exceeding the thermal design limits of the cable. Once commissioned, the CLPS will use real time modelling to identify the maximum power transfer available over a defined period of time to ensure the cable does not exceed its thermal rating.

Timeline for return of the dynamic capacity

The dynamic capacity will be made available once the CLPS has been successfully installed and commissioned and certain associated milestones (e.g. insurance sign off, engineering verification) have been completed. The current project schedule (which remains subject to change) is for commissioning activities to commence on 5 February 2024. At this stage, APA expects commercial operations to commence during Q2 2024, however this timeline is likely to be revised through the course of commissioning. APA will provide updates accordingly.

Availability of the dynamic capacity

If Basslink has been utilised below the continuous capacity (this changes each month and the values are available to the market through PASA) for a period of time (blue shaded section below), the cable and the environment around the cable will cool.  This pre-cooling will enable Basslink’s dynamic capacity (red shaded section below) to exceed the continuous capacity for a period until the thermal limit is reached.

APA is currently working with AEMO to agree the most appropriate way to update the PASA bids for Basslink to reflect dynamic operations and will provide periodic updates through the commissioning period.

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