About the DSN

In Victoria, the electricity transmission network is referred to as the Declared Shared Network (DSN). This section sets out the roles of the entities responsible for Victorian transmission connections.

Network Service Provider (NSP)

In Victoria, AEMO Victorian Planning and Connections (VP&C) performs some of the responsibilities in planning and augmentation carried out in other states by the connecting TNSP. AEMO’s Victorian NSP manages the DSN connection process and is the main point of contact for the Connection Applicant via vic.connections@aemo.com.au 

It also assesses the need for network augmentations (including regulatory cost/benefit assessment) and their contestability:

Augmentation interface works to the DSN are generally non-contestable and can only be undertaken by the incumbent Declared Transmission System Operator (DTSO).
For the remaining contestable parts of the augmentation, the Connection Applicant may directly nominate a preferred DTSO, conduct an Invitation To Tender (ITT) to select a suitable DTSO, or request VP&C to do so.

Declared Transmission System Operators (DTSO)

DTSOs build, own and operate transmission network infrastructure in Victoria.

DTSOs are registered in the National Electricity Market (NEM) as TNSPs and must hold a transmission licence in Victoria.

Victorian DTSOs

Australian Energy Market Operator (AEMO)

AEMO has an advisory role for transmission and distributions connections across all NEM regions via NEM.connections@aemo.com.au

AEMO’s Onboarding and Connections team liaises with the TNSP (or DNSP) that is establishing or modifying connections to the NEM. This involves:

Consulting on the system strength preliminary impact assessment
Providing transmission network data, models and advisory services
Undertaking due diligence of proposed performance standards and system strength remediation schemes.
Reviewing and approving negotiated performance standards that are AEMO advisory matters.

In relation to the Victorian DSN, the connecting TNSP is AEMO’s Victorian Planning and Connections team (see above).

AEMO’s Registration team processes NEM participant registration applications via onboarding@aemo.com.au

Contestability

If your connection requires an augmentation to the DSN, cost of that augmentation is incorporated into network service charge. If another connection project later uses this augmentation your network services charge may be reduced from the date that project is connected in accordance with the Cost Allocation Policy.

Transmission Augmentations in the Victorian DSN may be contestable. Clause 8.11.6 of the NER details the contestability framework for contestability in the DSN.

An augmentation is generally contestable if:
the cost of the augmentation is expected to be greater than $10 million, and
the augmentation is not hard to separate from existing transmission infrastructure, and
AEMO does not consider contestability to be uneconomic, impractical, or adversely impacting power system security.

If an augmentation is contestable, you are permitted to competitively source the construction and operation of an augmentation from a qualified DTSO who is not the incumbent DTSO. In Victoria there is no requirement for a competitively sourced augmentation of the DSN to be transferred to the incumbent DTSO for operational purposes post service commencement. A non-contestable augmentation must be constructed and operated by the incumbent DTSO – that is, the DTSO which owns and operates that part of the transmission system being augmented.

Inter-network Impact of Augmentations

Augmentations having a material inter-network impact may require an inter-network test. AEMO assesses if the augmentation may have a material inter-network impact.

Augmentations Requirements

The connection process generally depends on:

Need for DSN augmentations – to network assets as well as protection, control and monitoring systems.
Type of DSN augmentations required – to shared, interface or connection assets. Shared network assets include transmission lines, transmission tie transformers, busbars, circuit breakers and associated plant. Interface assets connect new shared network assets to the existing DSN, and are mainly transmission line cut-in works and changes to protection, control, and monitoring systems. Connection assets are plant connecting the Connection Applicant’s facility to the DSN, such as connecting transformers and associated high-voltage circuit breakers that are not already part of the shared network.

Obligation to fund augmentations depends on the type of service required:

Negotiated services – meet connection needs of an individual user or a small group of users that connect at the same point to the DSN, and do not deliver system-wide benefits. These services are solely funded by their users for the life of the augmentation (typically 30 years) through regular network charges. If other users connect at the same connection point, the augmentation costs will be shared between all users in accordance with AEMO’s cost allocation policy. These services can be provided by way of contestable or non-contestable augmentations.
Prescribed services – enhance the transmission system for all users. AEMO assesses whether a proposed augmentation to the DSN meets regulatory obligations and delivers system-wide net benefits. Net benefits are assessed by using a cost benefit analysis to compare the costs of the augmentation with the benefits it will deliver to network users and, ultimately, to end-use electricity consumers. The charges associated with the augmentation will be recovered from all transmission network users through Transmission Use of System (TUoS) charges. The cost benefit analysis may require public consultation.