Second Bass Strait interconnector technically feasible

Tasmania’s plan to become the ‘battery of the nation’ is one step closer, with the initial findings from a feasibility study predicting a second interconnector may be commercially viable in the 2030s or even sooner.

TasNetworks and ARENA this week released the initial findings from the feasibility study and business case for the proposed ‘Marinus Link’ – a second undersea interconnector cable after the current Basslink.

Last year, ARENA and TasNetworks committed to jointly fund the $20 million study, announced by the state and federal governments in November 2017.

This week, Prime Minister Scott Morrison and Energy Minister Angus Taylor also jointly announced $56 million additional funding for the next stage of the second interconnector project.

The initial study report found Marinus Link was technically feasible as either a 600 MW high voltage direct current cable or a 1200 MW interconnector delivered as two 600 MW stages.

According to the initial findings, the capital cost of the interconnection options would range from approximately $1.3-1.7 billion for the 600 MW option or $1.9-3.1 billion for the 1200 MW capacity option.

The final report from the ARENA-funded study is expected by the end of 2019.

The study is complementary to the work being undertaken by Hydro Tasmania to explore whether Tasmania could play a greater role in the National Electricity Market as the transition to renewable energy accelerates.

The construction of additional interconnection between the island state and mainland is a vital element in a plan laid out by the state and federal governments to make Tasmania the ‘battery of the nation’ and bolster the NEM as more renewables come online.

First announced by former Prime Minister Malcolm Turnbull in April 2017, the ambitious plan aims to expand Tasmania’s hydro and wind generation to provide backup for mainland states as ageing fossil fuel generators are retired.

The business case will depend on how rapidly the NEM transitions to renewable energy, but the report finds (pg 15) the benefits of the Marinus Link will likely outweigh its cost in the mid 2030s. If existing fossil fuel generators are retired before they reach the end of their design life, the new interconnection could become viable as soon as the mid 2020s.

As part of the study, TasNetworks have identified possible routes for the interconnector to pass between Tasmania and Victoria.

Tasmania's rugged north coast
Tasmania’s rugged north coast.

The preferred route to connect Sheffield or Burnie in Tasmania’s north west and Latrobe Valley will be identified soon, and is subject to consultation with the local communities.

TasNetworks CEO Lance Balcombe says the second interconnector will be vital to unlock Tasmania’s potential to become an energy storage powerhouse, and allow more renewables to come online in Victoria and Tasmania.

“Marinus Link is poised to support energy security by providing a reliable supply of electricity to Tasmanians and other Australians,” Balcombe said.

“This is currently being explored through Hydro Tasmania’s Battery of the Nation Project,” he said.

Work on the undersea link is being undertaken alongside other research scoping opportunities to grow Tasmania’s renewable energy output.

The early stages of the project have found 14 potential sites for new pumped hydro generators and scoped the potential to expand two existing hydroelectric power plants.

Prime Minister Scott Morrison also announced a further $30 million in funding under the federal government’s Underwriting New Generation Investments Program to accelerate Hydro Tasmania’s investigation to refine their shortlist of 14 sites down to three preferred options and ultimately identify a single pumped hydro site which could be constructed by 2025 to take advantage of new interconnection being built.

The Battery of the Nation’s Future NEM assessment has also identified opportunities to harness Tasmania’s wind resources, which are well positioned to complement mainland wind farms.

ARENA has provided funding for early works exploring how the Battery of the Nation initiative could support Australia’s transition to renewable energy.

ARENA CEO Darren Miller says the second interconnector could provide a way for Tasmania’s vast hydro resources to be used to support the National Electricity Market as it transforms over the coming decades.

“Tasmania has vast renewable energy potential – including wind and pumped hydro – ready to be developed,” Miller said.

“In order to maximise the potential of Tasmania we need to ensure there is enough interconnection to the mainland.

“There is a lot of work still to be done, but the initial findings are promising,” he said.