• Improving Access to the SWIS

    The arrangements by which generators gain access to Western Power’s network in the South West Interconnected System (SWIS) are critically important, as they determine the ability of the generator to participate in the Wholesale Electricity Market and provide electricity to households and businesses in the south west.

    Current network access arrangements do not make the best use of available transmission capacity and the existing investment in the network, resulting in barriers to entry for new generators. The arrangements have also led to an outcome where generators have different rights to access the network, creating inefficiencies in the dispatch of generators in the Wholesale Electricity Market.

    The proposal to adopt a framework of constrained access aims to improve generator access to the Western Power network by providing more equitable access for generators and optimising grid use. This will help remove barriers to investment and facilitate access to the Wholesale Electricity Market for new low-cost and cleaner generation technologies. By facilitating more efficient use of available network capacity, the reforms will also provide a greater return on the investment in new and existing network infrastructure that is ultimately paid for by electricity consumers in the south west.

    Project Elements

    Constrained access will be implemented primarily by the application of security constrained economic dispatch in the Wholesale Electricity Market. This will require:

    • Measures to transition existing network access arrangements to operate and be consistent with a constrained network access model, and appropriately managing the issues that arise from this transition.
    • A new process for allocating reserve capacity credits under the Reserve Capacity Mechanism to ensure it is consistent with a constrained network access environment.
    • New arrangements for the dispatch of generators in the Wholesale Electricity Market and market systems to incorporate security constrained economic dispatch principles. This will be progressed under the Delivering the Future Power System work stream.

    Changes to facilitate the reforms will be progressed largely through amendments to the Wholesale Electricity Market Rules and the Electricity Networks Access Code 2004, developed by the Energy Transformation Taskforce, in consultation with industry stakeholders.


    Consultation papers released by the Public Utilities Office on the implementation of constrained access and submissions received in response are available here.

    Contact for further information

    All enquiries on this project can be directed to (08) 6551 2397 or [email protected].

    Last reviewed: May 2019

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