What is Marinus Link?

Marinus Link is a proposed 1500 megawatt capacity undersea and underground electricity connection to further link Tasmania and Victoria as part of Australia’s future electricity grid. Marinus Link will be supported by transmission network developments on the North West Tasmanian electricity network.

Marinus Link involves approximately 250 kilometres of undersea High Voltage Direct Current (HVDC) cable and approximately 100 kilometres of underground HVDC cable. It will also include converter stations in Tasmania and Victoria, and approximately 220 kilometres of supporting High Voltage Alternating Current (HVAC) transmission network developments in North West Tasmania.

Together, Marinus Link and the supporting transmission developments will unlock Tasmania’s renewable energy and storage resources to deliver low-cost, reliable and clean energy for customers in the National Electricity Market.


Where will Marinus Link go?

The proposed route for Marinus Link will run from North West Tasmania to the Latrobe Valley in Victoria.

Marinus Link will not follow the same route as Basslink in Tasmania or Victoria. This geographic diversity will support a more reliable and secure electricity supply for customers.

The proposed location of Marinus Link in North West Tasmania enables connection into some of Australia’s best renewable energy and storage resources. In Victoria, the proposed connection is at Hazelwood Substation where there is access to significant Latrobe Valley transmission capacity.


What is an interconnector?

Interconnectors are a key feature of the future energy landscape.

Interconnectors connect two or more transmission networks. They allow power to flow between different regions (i.e., between Tasmania to Victoria), including to enable the efficient transfer of electricity from renewable energy generation zones to where the electricity is needed.  Interconnectors can increase the resilience of the National Electricity Market (NEM) and make energy more secure, affordable and sustainable for customers.

Interconnectors are common around the world including in Australia. They play a critical role in supporting Australia’s transition to a clean energy future.


What is the National Electricity Market (NEM)?

The NEM is one of the largest interconnected electricity systems in the world. It covers around 40,000 km of transmission lines and cables, supplying around 9 million customers.

The NEM is a wholesale market through which generators and retailers trade electricity in Australia. It interconnects the six eastern and southern states and territories and delivers around 80% of all electricity used in Australia.


Why is this project needed?

Marinus Link and supporting transmission provide access to clean, dispatchable energy capacity and can play a critical role in Australia’s energy transformation. Alternative solutions to provide similar reliability would come at a higher cost.

The National Electricity Market is transforming as coal-fired generation continues to retire and variable renewable generation, such as wind and solar, take its place.

Large and small-scale solar and wind generators produce clean and low-cost power, but there can be shortages in supply when the wind is not blowing and/or when the sun is not shining.

Hydroelectric generators and storage resources, such as pumped hydro energy storage, can support solar and wind generation by storing excess energy and then make it available to customers as required.

Marinus Link and the supporting transmission developments in North West Tasmania will provide access to Tasmania’s cost-competitive renewable energy and storage resources.

They will enable energy to move efficiently from a diverse range of sources to where it is most needed. For example, they could enable excess energy from mainland Australia to be sent to Tasmania to be held in pumped hydro energy storage resources, ready to be released as required. In this way, Marinus Link and supporting transmission will help provide grid stability, addressing supply shortages, and keep electricity prices lower than they otherwise would be.


What are the benefits of this project?

Work undertaken by TasNetworks as part of the Regulatory Investment Test – Transmission (RIT-T) process shows that Marinus Link and the supporting North West Tasmania transmission developments deliver electricity market benefits that are greater than their costs. TasNetworks’ RIT-T analysis continues, together with work by the Australian Energy Market Operator as it develops an Integrated System Plan for the NEM to meet customer energy needs in the years and decades to come.

In addition to providing energy market benefits, the project also presents a valuable opportunity to stimulate employment, jobs and investment in local communities. It will create billions in economic growth, thousands of jobs, and be a source of skills development in Tasmania and regional Victoria.

On its own, the project will provide a broader economic contribution to regional communities in Tasmania and Victoria estimated to be up to $2.9 billion, together with 2,800 jobs generated at peak construction.

In Tasmania the project will also unlock a pipeline of investment in renewable generation and storage developments. This includes new wind farms and the potential for pumped hydro energy storage that would be enabled by a 1500 megawatt Marinus Link. These renewable energy developments have an estimated value of up to $5.7 billion, and would create an additional 2,350 jobs during peak construction.

In Victoria, Marinus Link will support renewable energy developments by providing firming capacity to wind and solar developments and opportunities for Victoria to transfer excess renewable energy to Tasmania. This means that energy generated in Victoria that would otherwise be wasted could instead be stored in Tasmania’s existing hydro storage facilities or new pumped hydro energy storage facilities, ready to be used when needed.


How do the project’s benefits translate to the cost of electricity?

The benefits to the National Electricity Market that Marinus Link and supporting transmission would unlock include:

  • Enabling untapped and cost-competitive renewable wind, solar, and long-duration (sometimes referred to as “deep”) pumped hydro energy storage;
  • Increasing supply security and firming renewables by providing clean, dispatchable energy;
  • Harnessing a diversity of load and generation;
  • Managing the risks of relying on a single interconnector across Bass Strait;
  • Complementarity with existing and future interconnectors on mainland Australia; and
  • Utilising robust and flexible converter technology to provide services to support the power system.

From a practical perspective, these benefits mean the cost of electricity supply in the NEM would be relatively lower with Marinus Link in service.

In a competitive energy market, this should translate to relatively lower electricity prices for customers in the NEM than prices otherwise would have been without Marinus Link and supporting transmission.


When will construction work begin and how long will it last?

The project is on-track to deliver a ‘shovel ready’ Marinus Link and supporting transmission by the mid 2020s, ready to be in service when required. TasNetworks’ modelling suggests the optimum timing for the project to be in service is from the late 2020s.

Work continues to progress key activities in the Design and Approvals phase. Once this phase is complete, the project can move to the construction phase, noting that Marinus Link is presently being planned for a two stage development. It is estimated to take approximately four years to manufacture, install and commission equipment for the first 750 megawatt (MW) stage, with the second stage estimated to take a further two years.

In light of recent bushfires in Australia, particularly in Gippsland, Victoria, and with the onset of the Covid-19 Coronavirus pandemic, we are re-assessing our project schedule and key activities. While the situation is still unfolding and the long term impacts of Covid-19 are not yet known, we remain confident that Marinus Link and the supporting transmission developments can be shovel ready by the mid-2020s and in service when the market needs it.


How much will it cost and who will pay for this?

A total project cost is estimated to be in the range of $3.5 billion ($2020). This includes accuracy and contingency allowances appropriate for this stage in the project lifecycle.

TasNetworks’ analysis shows that a regulated service model for Marinus Link and supporting transmission, supported by a ‘beneficiaries pay’ customer-pricing framework, is the preferred option.

A regulated service model means that project costs would be reviewed by the Australian Energy Regulator (AER) to ensure the costs are efficient, with the resulting annual revenue allowed by the AER recovered from electricity customers through the network charge component of their bill.

Under the current transmission pricing rules Tasmania and Victorian customers would pay for Marinus Link and supporting transmission. This isn’t a fair outcome because all regions in the National Electricity Market (NEM) will benefit from the project – particularly customers in mainland Australia.

An approach is needed where those customers who benefit from a transmission investment, including through lower power bills, fund the investment over its forecast service life.

This issue is recognised by Council of Australian Governments (COAG) Energy Council, with a transmission pricing review underway.

An appropriate customer pricing outcome is required for the project to proceed and we continue to support our Shareholder Ministers in working through COAG processes to resolve this issue.


Who will own and manage Marinus Link and its supporting transmission?

A range of ownership and operating options for Marinus Link are open to the project. The supporting transmission required in Tasmania will be owned and operated by TasNetworks.

How can I have my say?

We are committed to maximising engagement opportunities and to communicating in a transparent, respectful, and timely manner with the broad range of stakeholders relevant to Marinus Link and the supporting transmission developments.

In light of Covid-19, planning for engagements is under review. We’d like to hear from you about how we can engage with you and your community during this time, so please get in touch via the contact details below.

You can contact us via our project email and phone line with any questions about the project. If you want to find out more you can also visit the TasNetworks website

Email: team@marinuslink.com.au


What does Tasmania’s 200% Renewable Energy target mean for the project?

Link is a cornerstone of the recent policy announcement from the Tasmanian Government of 200% renewables by 2040. The project enjoys bipartisan support at State and Federal levels.

The 200% Renewable energy target announced by the Tasmanian government reinforces the potential Marinus Link provides to provide access to low cost, clean and reliable energy resources as part of Australia’s transition to a lower emissions energy future.


Does the Victorian Government Support this project?

The Victorian Government supports the development of the project, whilst recognising there are a number of other transmission projects underway and being progressed to support Victoria’s changing energy mix.

If Snowy 2.0 goes ahead, will this project still be needed?

The NEM needs the generation and storage capacity unlocked by Marinus Link and the supporting North West Tasmania transmission developments, regardless of whether or not Snowy 2.0 goes ahead.

By 2035 at least 12,000 MW of coal-fired generation is forecast to retire in the National Electricity Market (NEM). Modelling shows that to replace this will require 40,000 MW of variable renewables, such as wind and solar generation, and at least 8,000 MW of dispatchable generation, such as hydroelectric and gas generation, together with deep storage capacity from pumped hydro resources. This is in addition to the 2,000 MW of dispatchable generation that the Snowy 2.0 project would provide. Continued improvements in customer energy efficiency, demand response and battery technologies are also forecast to play a greater role in the future NEM.

Projects such as Snowy 2.0 and Marinus Link and the supporting North West Tasmania transmission developments form part of the “low-cost, low-regret development path” identified in the Australian Energy Market Operator’s Draft 2020 Integrated System Plan. They are just two of many generation and transmission developments required as the NEM continues to transform in coming decades.


Is this a priority project for Australia?

Infrastructure Australia has once again given Marinus Link ‘high priority’ status in its 2020 listing of nationally significant initiatives that form part of a future, more interconnected, NEM. The project was also included as a high priority initiative by Infrastructure Australia in 2018 and 2019.

The project received bipartisan support from both major political parties at the Federal election held in May 2019.  The Australian Energy Market Operator (AEMO) Integrated System Plan assessment released in late 2019 agrees that Marinus Link should progress to be ‘shovel ready’ as soon as practicable to meet the energy transition that is underway.


What does COVID-19 mean for the project?

Like so many other businesses and project teams, we are re-assessing our project schedule and key activities in light of the Covid-19 Coronavirus pandemic.

We continue to progress activities for the design and approvals phase, adjusting our methods and anticipated timelines where necessary. We remain confident that we will still have Marinus Link and the supporting transmission developments shovel ready by the mid-2020s, and in service when the market needs it. TasNetworks’ modelling suggests the optimum timing for the project to be in service is from the late 2020s.


What is a converter station and how big would it be?

A converter station converts electricity between Alternating Current (AC) and Direct Current (DC). AC is used in each state’s transmission systems, while DC at transmission voltages is often used for sending high volumes of electricity long distances undersea.

The overall footprint of each 750 megawatt converter station is approximately 33,000 square metres (220 metres by 150 metres), including a range of buildings, outdoor equipment and access roads. The largest building is the converter hall, with an overall footprint of approximately 2,000 square metres and a height of up to 22 metres.  This ‘technical’ area excludes any land required for any drainage systems or landscaping / screening, which will vary depending on the location. 


What is a substation?

A substation is a point of connection to an electricity network that allows transmission lines to connect/disconnect, and to connect between different voltage networks.  It is where the voltage of electricity can be stepped up to flow into the high voltage transmission system or stepped down to supply consumers.



Marinus Link would connect two High Voltage Alternating Current (HVAC) electricity systems, which are separated by the Bass Strait using a ~250 km High Voltage Direct Current (HVDC) undersea cable. HVDC allows for the efficient transportation of electricity over large distances and, in particular, for submarine applications. The technology proposed for Marinus Link is also highly controllable and will bring operational benefits to transmission systems in Victoria and Tasmania.



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