When Marinus Link was first conceived in 2017, it was developed to strengthen Tasmania and Victoria’s electricity connection and complement the existing 500MW Basslink interconnector as demand growth and the energy transition began to reshape the National Electricity Market.
Eight years on and after proving its technical and economic viability, a final investment decision was made on the 750MW stage one of Marinus Link in August 2025, with early works commencing on the project this year. Stage two of the project would add another 750MW of capacity (1500MW all up).
So what can this interconnector offer for Tasmania, Victoria and the broader NEM?
“Stage one of Marinus Link will offer grid flexibility, so as coal-fired power stations close down, Tasmania can export – through Hydro Tasmania – greater amounts of hydropower to Victoria and the National Electricity Market,” Marinus Link Manager – Media and External Communications Justin White said during a site tour last week.
“Then during days when Victoria has oversupplies of wind and solar, Tasmania can import these resources allowing Hydro Tasmania to save its hydropower to be deployed during periods of peak demand in Victoria or times when there’s not enough supply from Victoria’s generation assets.
“So Marinus Link enables Tasmania to support Victoria through its transition of coal-fired closures, while Tasmania gets the benefit of oversupplies of low-cost variable renewables such as solar.”
White said Tasmania is often subject to a “chicken or egg” scenario.
“If there’s no new loads, industrial loads or increases in demand, Tasmania doesn’t get additional investment in renewable energy,” he said.
“But by unlocking extra capacity, Marinus Link enables local wind farms and hydropower assets to be upgraded, which then means new loads, industrial demand and investment can come to Tasmania, such as data centres or biofuels plants, to name a few.”
White said by opening up additional access to hydropower, this can be increasingly relied upon over gas-fired generation in the NEM, which places downward pressure on wholesale electricity prices during peak demand periods.
“This pushes Victoria’s wholesale prices down, which also pushes Tasmania’s prices down,” he said.
Marinus Link is set for completion in 2030.
