'Battery of the nation' undersea power cable at risk

The multi-billion-dollar Marinus Link undersea power cable project to connect Tasmania to the mainland has been touted as critical to making the island state the "battery of the nation" by increasing its capacity to export green power.

The $5.5 billion project is set to be funded by the federal, Tasmanian and Victorian governments. 

The Tasmanian government's decision on its 17.7 per cent share of the link's Stage 1 cable, initially promised by July 31, has been delayed.

Tasmania's Shadow Energy Minister Janie Finlay on Saturday accused Premier Jeremy Rockliff of blocking a briefing from Energy Minister Nick Duigan on the Marinus business case. 

It had been hoped the briefing would create bipartisan support to secure the project as Tasmania's Liberal government scrambles for survival following the July 19 election. 

"We are days away from a critical decision on one of Tasmania's largest infrastructure projects," Ms Finlay told reporters.

"The business case has been sitting in the premier's office for two months, but Jeremy Rockliff won't let Tasmanians see it.

"Not only have they just not briefed Tasmanian Labor, but the premier has stepped in and actively blocked that."

Tasmanian Minerals, Manufacturing and Energy Council chief executive Ray Mostogl said the delay and uncertainty placed the entire project at risk.

Marinus Link must "issue notice to proceed" by the end of August or lose a $1.07 billion contract with the Italy-based ­Prysmian Group to supply the 345km cable.

Tasmania's Liberal government is in caretaker mode after the state election delivered another large crossbench, some of whom oppose the Marinus project.

Ms Finlay accused the Rockliff government of hiding the Marinus Link business case for political gain because it included significant price impacts to pay for transmission infrastructure.

The government has denied Mr Rockliff or his staff blocked a briefing, saying the opposition would be briefed in line with caretaker conventions.

"We are carefully and methodically working through the details, with a decision expected soon," Mr Duigan said.

The undersea electricity and data connector would link Tasmania's northwest with Victoria's Latrobe Valley and allow the smaller state to import surplus solar while exporting hydropower to the mainland grid, where it could help reduce the risk of brownouts.

The project was scaled back in September 2023 after the cost of two cables blew out by $1.7 billion to an estimated $5.5 billion.

Under the plan, Victoria has a 33.3 per cent share and Tasmania 17.7 per cent, with an option to sell its stake to the Commonwealth on completion.

Marinus Link has been touted as a critical component in making Tasmania the "battery" of the nation by increasing the island's capacity to export green power and allow excess energy generated on the mainland to be stored in Tasmania's hydro storage.

The first stage is not slated to be finished until 2028/29.  

Australian Associated Press