The Australian Energy Regulator (AER) has published its final decisions for the Marinus Link Stage 1, Part B (construction costs) and the North West Transmission Development (NWTD) Stage 1 contingent project application (construction costs) following a thorough stakeholder consultation process and assessment of the proposed costs.
The combined Marinus Link and NWTD projects form Project Marinus. Stage 1 will deliver a 750-megawatt cable connecting Victoria and Tasmania (Marinus Link), and associated transmission upgrades to the existing on-land transmission network in north west Tasmania (NWTD). Stage 2 will deliver a second 750-megawatt cable connecting Tasmania and Victoria.
AER Chair Ms Clare Savage said the AER had closely scrutinised Stage 1 proposals, particularly the sharing of risk between Marinus Link, TasNetworks and consumers, which was a large theme during consultation.
“There has been significant interest and a diverse range of views from stakeholders through our consultation process, reflecting the complexity of a project of national significance across multiple states.
“The construction and transmission upgrade costs in these proposals are a large amount of the total costs for Project Marinus and have been market tested. We have closely examined all costs and considered feedback from stakeholders to ensure consumers pay no more than necessary for this important project,” said Ms Savage.
The AER’s final decision is to approve proposed capital expenditure of $3,470.6 million for Marinus Link’s Stage 1 construction costs − $27.8 million less than proposed by Marinus Link – with a reduced, efficient risk allowance and reduced corporate costs.
This adopts a balanced approach to risk sharing between Marinus Link and consumers, providing incentives for Marinus Link to mitigate risks and contain costs that are ultimately paid for by consumers, while providing it with the opportunity to recover its construction costs.
Costs for Marinus Link will be recovered from Tasmanian and Victorian electricity consumers once Marinus Link commences services, which is currently expected in 2030. The allocation of costs for Marinus Link will be based on an agreement between governments.
Marinus Link is also in discussions with the Clean Energy Finance Corporation on the details of a concessional finance agreement, with the benefits of any agreement to be passed on to consumers through lower transmission charges.
For the NWTD Stage 1 construction costs, the AER has also applied a reduced risk allowance, approving proposed capital expenditure of $921.3 million, which is $49.8 million less than proposed by TasNetworks.
These Stage 1 construction costs for the NWTD will result in an annual bill increase of around $15.50 for a typical Tasmanian residential electricity customer over the remaining 3 years of the 2024-29 regulatory period. This is an upper limit because it does not account for the impact of any Commonwealth grant funding and the concessional financing agreement for NWTD, which is expected to be finalised shortly.
“We thank everyone who has participated in these processes and encourage them to continue to engage with the AER on future revenue determinations for Marinus Link and TasNetworks, in anticipation of Marinus Link’s transmission services starting in 2030,” said Ms Savage.
Notes to Editors
Marinus Link revenue determination
- In December 2023, the AER published its final decision in relation to Marinus Link Pty Ltd’s (MLPL) Stage 1, Part A (Early works) revenue proposal.
- In November 2024, MLPL submitted its Stage 1 Part B (Construction costs) proposal.
- The Commencement and Process Paper sets out a staged approach for the construction costs determination, including a May 2025 Initial Draft Decision, November 2025 Supplementary Draft Decision and this Final Decision in February 2026.
- In November 2025 the AER published the Supplementary Draft Decision.
- In December 2025, MLPL submitted its response to our Supplementary Draft Decision.
- The AER will commence its revenue determination process for MLPL for the 2030-35 regulatory period in 2029.
North West Transmission Development contingent project application
- In March 2025, the AER published its final decision in relation to TasNetworks’ NWTD Stage 1 (Early works) contingent project application.
- In October 2025, TasNetworks submitted a contingent project application on the construction of Stage 1 of the NWTD.
- The AER will commence its revenue determination process for TasNetworks for the 2029-34 regulatory period in 2028.