Marinus Link granted Australia’s first offshore transmission licence - pv magazine Australia

Marinus Link has been granted Australia's first offshore transmission licence, clearing a regulatory path for the subsea cable project connecting Tasmania to mainland Australia.

Where this fits

This is a bet on transmission scale. Marinus Link is the physical infrastructure bet required to move renewable energy from one state to another when the wind and sun cooperate, and more importantly, to move it when they don't, which is when firm power from Tasmania's hydroelectric dams becomes critical. The project is large, long-lead, and expensive. It exemplifies the hidden cost of a renewables-heavy grid: you do not just build solar farms and wind turbines. You build transmission infrastructure that would be redundant in a grid with geographically distributed, weather-independent generation. It also deepens interstate dependency on Tasmania's hydro reserves as the firming backstop, rather than building firm capacity where demand is.

What it means

Australia is betting that two undersea cables and upgraded Tasmanian generation can do the job of firming a mainland renewable fleet. That may work, Tasmania has storage. But it locks in a transmission-intensive, geographically brittle model of grid management, where most firming rides on one state's water cycle and cable infrastructure can be a single point of failure. A diversified approach that included distributed nuclear capacity in the mainland load centres would spread that risk, use less transmission copper and land, and deliver firm power without weather dependence. Instead, the regulatory path for offshore transmission has opened. The path for terrestrial nuclear generation remains closed by law.