Capitalised terms used on this webpage which are:
(a) not italicised have the meanings given in this content or the Access Policy for the Western Downs DNA; and
(b) italicised have the meanings given in the Rules.
Australian Energy Regulator Approval Date
The Access Policy for the Western Downs DNA was approved by the Australian Energy Regulator on 26 February 2025.
For the purpose of Appendix F of the Access Policy, the end date of Foundation Proponent No. 1’s connection agreement is 7 December 2055.
Details of Western Downs Designated Network Asset Capacity and Facilities of Existing Connected Parties (as at the AER Approval Date)
Schematic of the connection configuration for the Western Downs DNA and associated assets (as at the AER Approval Date)
Note: The blue shaded areas represent the two bays used to provide negotiated transmission services to the Western Downs DNA and does not form part of the Western Downs DNA but is inherently required to connect the Western Downs DNA to the transmission network.
Main Components of the connection
The table below describes the main components of the Western Downs DNA and associated assets.
| No | Asset Component | Description |
|---|---|---|
| 1 | DNA Component 1 | 48.5km of 275kV double circuit transmission line between Halys Substation to the Diamondy Switching Station and associated easements. |
| 2 | DNA Component 2 | 275kV Diamondy Switching Station and associated access easement. |
Refer to the hybrid general arrangement drawings for Diamondy Switching Station and Halys Network Substation for further details.
Western Downs DNA capacity
The Western Downs DNA is primarily limited by the thermal capacity of DNA Component 1 (the 275kV transmission lines between Halys Substation and Diamondy Switching Station). DNA Component 1 includes two circuits configured as a single circuit. Under normal operating conditions, the single circuit has a limiting transfer capacity of 750 MVA (refer to Table 1 in the Western Downs DNA Access Operational Protocol for further details). Note the DNA Capacity is subject to non-DNA limitations/constraints/conditions existing, from time to time, on the Shared Transmission Network that impact the maximum capacity into, across and out of the Western Downs DNA.
Powerlink will engage with an Applicant in more detail about its desired Agreed DNA Transfer Limit for DNA Service 1 for a proposed connection project prior to and/or after a DNA Access Request has been submitted.
Facilities of Existing Connected Parties and Conditional Proponents
| Project | Nameplate capacity (MW) | Agreed DNA Transfer Limit (MVA) |
|---|---|---|
| Wambo Wind Farm 1 | 252 | 263 |
| Wambo Wind Farm 2 | 254.2 | 266 |
A congestion management scheme will be introduced to manage access to the transfer capacity of the line during Western Downs DNA congestion.
DNA component limitations
| No | Description (collectively “Component Limitations”) | DNA Transfer Capacity | DNA Transfer Capacity following upgrade |
| 1 | The Western Downs DNA is limited by DNA Component 1 which is configured as a single circuit. | With the single circuit in service: 750 MVA.1
During a DNA Contingency Event, 0 MVA. | Upgrade by cutting in the second circuit of the double circuit feeder. Following this upgrade, the DNA Transfer Capacity with both circuits in service is: 1650 MVA1.
During a DNA Contingency Event, 750 MVA1. |
1 Subject to the operating envelope specified in the Western Downs DNA Access Operational Protocol.
DNA Access Operational Protocol
Read the current DNA Access Operational Protocol for the Western Downs DNA.
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