Marinus Link launches largest underwater engineering survey of Bass Strait

Marinus Link, the company behind the proposed 1.5GW transmission link to the Australian mainland, has begun an underwater engineering survey of Bass Strait to determine the most suitable corridor for laying the project’s undersea cables.

The 87-metre long TEK Ocean Spirit departed the Port of Burnie over the weekend to begin the largest underwater engineering survey of Bass Strait, which will help to refine the final design and installation method for the proposed interconnector cable.

MMA Offshore won the $5.5 million contract to carry out critical engineering surveys last year, its TEK Ocean Spirit will take between four to six weeks to survey the 255-kilometres stretching between Heybridge in North West Tasmania and Waratah Bay in South Gippsland, Victoria.

The survey will take place over approximately 110 sites across Bass Straight in sea depths up to 80-metres.

“This survey builds on the results and analysis of previous surveys we have conducted,” said Sean Van Steel, offshore lead for Marinus Link. “The locations chosen to take samples have been selected to minimise the impact on the seabed floor, reefs and marine life.”

This is the third major marine survey for the $3.5 billion 1.5GW Marinus Link, and is designed to determine the most suitable corridor for the interconnector to take between Tasmania and Victoria, and is further proof of the company’s commitment to sensitively designing and building the connection.

“Marinus Link is key to Australia’s clean energy future – increasing reliability, placing downward pressure on electricity prices and cutting emissions by making the most of our high quality renewable energy resources,” said Bess Clark, CEO of Marinus Link.

The Marinus Link has passed a Regulatory Investment Test for Transmission (RIT-T) overseen by the independent Australian Energy Regulator (AER), and is included as an important part of the the Australian Energy Market Operator (AEMO) Integrated System Plan.

However, it does not have universal support. Many critics have been calling for the money to be redirected to building battery storage systems instead.

Currently, Tasmania’s aim to be the “battery of the nation” by connecting its huge renewable energy resources to the mainland, has the approval of the Morrison federal government.

But a number of people have been calling for distributed battery storage to be developed across Victoria. There has also been opposition to a further build-out of massive wind projects and transmission lines in Tasmania from former Greens leaders Bob Brown and Christine Milne.

In November 2021, a new analysis suggested that Tasmania’s goal of becoming the ‘battery of the nation’ could be rendered obsolete, as the cost of big battery projects continues to plummet.

Meanwhile, the existing interconnector between Tasmania and the mainland National Electricity Market, Basslink, remains in troubled waters, after its commercial contract with the Tasmanian government and state-owned utility Hydro Tasmania was terminated, last week.

Tasmania energy minister Guy Barnett said on Thursday that the state government and Hydro Tas had taken “another step” towards protecting their legal rights, by cancelling the Basslink Services Agreement (BSA).

The move is the latest in a years-long dispute between the two parties, that started when the Tasmanian state government sued Basslink for damages over the long interconnector outage that hit the island in 2015.

Barnett said that the termination of the commercial contract would not affect the state’s energy security, which remained on “firm footing” thanks to strong hydro storage levels and the Cattle Hill and Granville Harbour wind farms.

The undersea cable, meanwhile, would remain in service while negotiations continued with Basslink’s administrators “on alternative commercial arrangements, suitable for the receivership period,” Barnett said.