Tasmania Marinus Link would work best in fast transition to renewables | RenewEconomy

Tasmania Marinus Link would work best in fast transition to renewables

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Study finds new interconnector linking Tasmania and Victoria would provide greater benefits than costs under all modelled scenarios, but especially a fast transition to renewables.

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Plans to build a second interconnector linking the wind and hydro-rich island state of Tasmania to the mainland Australian grid could unlock up to $5 billion in new renewables investments, but only if the rest of the NEM keeps up a fast pace of clean energy transition.

A final business case assessment of the proposed $3.5 billion Marinus Link – the key to Tasmania’s goal of being the “battery of the nation” – has found that a installing a second undersea cable across the Bass Strait was feasible at 1500MW capacity and could be in service from as early as 2027.

The newly published $20 million TasNetworks feasibility study – supported by $10 million from the federal government’s ARENA – found that establishing the new link along with supporting transmission would “provide greater benefits than costs under all modelled scenarios.”

On its own, the report said, the Marinus Link was expected to provide an economic boost to regional communities in Tasmania and Victoria in excess of $2.9 billion.

With supporting transmission, it would unlock wider added value up to an estimated $5.7 billion in Tasmania renewables developments, including new wind farms and pumped hydro energy storage enabled by the additional 1500 MW capacity across Bass Strait.

As you can see in the chart above, the benefits improve vastly depending on the pace of the transition to renewable energy – and away from coal-fired power – in other NEM states, and in particular, Victoria.

This, of course, means that any delay to the planned retirement of Victoria’s ageing coal-fired power plants would have a direct negative impact on the business case for the new link.

“If built, Marinus Link could support Australia’s transition to a low emissions future by expanding the renewable electricity generation and storage capacity in Tasmania, which could be exported across Bass Strait to support the National Electricity Market (NEM),” a statement from TasNetworks said on Thursday.

“At present, Tasmania can only export 500 MW as it is limited by the capacity of the existing interconnector Bass Link.”

The business case proposes the best way forward for the new interconnector would be to build it in two separate HVDC cables of 750MW each, on a route running from north west Tasmania near Burnie to the Latrobe Valley in Victoria.

TasNetworks also released the findings of the regulatory investment test (RIT-T) for transmission, which found that the optimal timing for Marinus Link and supporting transmission was for the first 750MW of capacity to come into service in 2028.

Following that, and depending on the scenario used, the timing of the second 750MW of capacity would be installed between 2030 and 2032.

The report acknowledged that while a 2027 target date did not presently optimise benefits under the RIT-T, this timing would still provide net benefits to the NEM over the project’s life under all scenarios modelled, as you can see in the chart above.

TasNetworks said the plan, now, was to begin the design and approvals phase for Project Marinus, for which the Australian government had committed another $56 million through ARENA.

“Tasmania has the potential to support the renewable energy transformation of the NEM that is currently taking place,” said ARENA CEO Darren Miller in comments on Thursday.

“With this business case showing that Marinus Link is feasible, we could see its vast pumped hydro and wind potential playing a key role in providing clean, low cost and dispatchable power to the NEM in the future.”

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  1. Maddogeco 9 months ago

    2028 seem like a very long time away. Could the first cable be up and running in 3 years? Where is the majority of the time taken? Funding? Planning? construction? approval?

  2. Arnold Garnsey 9 months ago

    The case for duplicating Basslink became compelling when it went down last year 2018. The time for repairs affected the grids on both sides with Tas hydro was also seeing low dam levels from low rainfall. Repair and subsequent restart took near five months? followed by six weeks? fault chasing. A previous outage for six months occurred in 2015.
    Duplication was seen as critically important for energy security on both ends. Reliability concerns were also affecting proposals for wind farms which were also seen as necessary for Tas and capable of delivering substantial benefits to the mainland. Once Basslink became a strategic component with many dependant users, the duplication for reliability becomes not optional. If it can reduce energy costs and facilitate Tas renewable e it’s hard to find negatives.

    • JackD 9 months ago

      Unfortunately our electricity networks are not as highly valued as our banking industry IT networks. Under regulation, they create fully redundant networks featuring limited or no single points of failure.

      The Basslink incident is a case in point as is the Heywood – South East interconnector issue.

  3. JackD 9 months ago

    Another study and another report!!! What has to take place to get this happening? Some enormously lengthy and administratively cumbersome RIT or similar regulated process.

    The polar caps will have melted by the time the shovel is turned on the first sod.

    For Christs sake (pun intended), its like watching Life Of Brian except this story isn’t so nearly as entertaining.


    • Peter Farley 9 months ago

      The report seems to assume that Victoria will do nothing about dispersing its renewables toward the East/ flexible demand its own smaller pumped hydro, or whatever. The project is a white elephant now and will be even more so by 2028

  4. Ian 9 months ago

    Tasmania needs to move faster than this to get their Marinus Link going. Wait 7 or 8 years in the energy transformation world and you will be too late for the party. Others on the mainland would have built, connected, used and be almost ready for repowering their projects by the time the Marinus cable is laid in the water.

    • Charles 9 months ago

      Interestingly enough the documents give timelines under different circumstances (economic, renewables uptake etc) and it suggests at the fastest rate the demand for the first cable will be there about 2028 (second stage 2030), and the slowest closer to 2030 (second stage 2032). These can be adjusted based on what is actually happening closer to the date.

  5. Craig Fryer 9 months ago

    There are many issues not discussed in this article or the report in general (or it is well hidden).
    Reliability – Basslink has poor record. Would this be any better?
    The report talks about additional wind and hydro capacity in Tasmania to supply the rest of Australia. Does this mean there is no interest or capacity to take much from SA? The SA- Vic link already can’t meet the demand some times as it is.
    What would the efficiency of the PHS be?
    What about total round trip efficiency for Vic?
    What would the average storage capacity be (daily and longer term)?
    What would the impact of low rainfall be on the system?

    How does this compare to estimated battery storage costs. capacity and storage depth?
    (Projected out to 5 and 10 years for the two stages).

    Another concern is the usage policy and pricing for any storage in Tasmania is controlled by a monopoly in form of a Tasmanian Government own enterprise. A huge amount of capital could spent on an unreliable and expensive system that doesn’t work for the benefit of the Victorian or SA consumers or RE produces.

  6. Ren Stimpy 9 months ago

    So , what are they waiting for?

  7. rob 9 months ago


  8. Honest Mike 9 months ago

    great to see an article to raise awareness of the driver for interstate interconnector lines and importance of energy storage. Its surprising the number of people who dont seem to realise that energy storage enables renewables and 100% renewables is not possible without energy storage

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