Major construction has officially commenced this October 2026 on Project Marinus, a critical infrastructure initiative that includes the Marinus Link interconnector and the North West Transmission Developments (NWTD). This AU$5 billion project, spanning Tasmania and Victoria, is poised to deliver significant wholesale electricity price reductions, with forecasts indicating savings of up to AU$17/MWh for Victorian consumers and AU$15/MWh for Tasmanians.

The ceremonial sod-turning events, held in early October, mark a pivotal moment for Australia’s National Electricity Market (NEM), signalling a tangible step towards enhanced grid stability, reliability, and the integration of renewable energy resources across Bass Strait.

Project Marinus: A Dual-State Energy Highway

Project Marinus encompasses two key components: the Marinus Link, a 345-kilometre undersea and underground high-voltage direct current (HVDC) cable, and the interdependent North West Transmission Developments (NWTD) in Tasmania. Stage 1 of Marinus Link, a 750 MW interconnector, will stretch 255 km beneath Bass Strait from Heybridge, near Burnie in northwest Tasmania, to Waratah Bay on Victoria’s south coast, before continuing 90 km underground to the Latrobe Valley.

This two-way interconnector is designed to facilitate the bidirectional flow of electricity, significantly boosting transfer capacity between the two states. This capability is crucial for leveraging Tasmania’s abundant hydropower and growing wind resources, allowing excess renewable energy to be exported to Victoria when needed, and importing power to Tasmania during periods of high demand or low local generation.

Speaking at the sod-turning ceremony, Marinus Link Chair Sandra Gamble highlighted the project’s broad benefits:

“As a two-way interconnector, Marinus Link will allow electricity to flow in either direction, improving flexibility, reliability and resilience across the National Electricity Market, getting the most out of hydropower, wind and solar resources, and bringing on new investment in industry and generation.”

The NWTD component involves a substantial upgrade of Tasmania’s northwest electricity network, including approximately 240 km of new and upgraded overhead transmission lines. Stage 1 of NWTD, covering 129 km from Cressy to Burnie, is already underway, with activities including access tracks, fencing, tower foundations, and substation works.

Economic Impact and Investment Landscape

Marinus Link is not only a technical marvel but also a significant economic driver. The project is expected to support approximately 1,000 Victorian jobs annually during its construction phase and generate around AU$1 billion in economic activity for the state, with a substantial portion of the workforce drawn from local Gippsland communities. In Tasmania, more than 50 local businesses have already been engaged for NWTD works, with almost AU$55 million invested in 87 vendors.

The overall construction costs for Stage 1 of Marinus Link and the NWTD are projected to exceed AU$5 billion. The project has secured substantial financial backing, including a AU$3.8 billion commitment from the Clean Energy Finance Corporation (CEFC) via its Rewiring the Nation Fund, structured to reduce borrowing costs.

A joint venture between Malaysian construction group Gamuda and South Korean engineering firm Samsung C&T holds the AU$994 million balance of works contract, covering civil, structural, and electrical work, including the vital converter station buildings.

Strengthening the NEM and Future Grid Stability

The completion of Marinus Link, scheduled for late 2030, will add 750 MW of firm capacity to the NEM, providing 50% more transfer capacity than the existing Basslink interconnector. This additional capacity is vital for managing the increasing penetration of intermittent renewable energy sources across the NEM. By allowing greater energy exchange, Marinus Link will help to stabilise the grid, reduce curtailment of renewable generation, and ensure a more reliable power supply for homes and businesses.

Victoria’s converter station at Hazelwood North will incorporate advanced grid-forming technology developed by Hitachi Energy. This technology is designed to actively maintain stability across the electricity network, a critical function as coal-fired power stations retire and the grid transitions to higher levels of renewable energy.

This project aligns with broader national efforts to modernise Australia’s grid infrastructure and improve market efficiency. Increased interconnector capacity is a key recommendation in the Australian Energy Market Operator’s (AEMO) Integrated System Plan (ISP), which outlines the least-cost pathway to a reliable and secure energy future. For consumers, the enhanced connectivity and greater availability of cheaper renewable energy through projects like Marinus Link are expected to translate into more competitive electricity prices. Understanding how these wholesale price changes may impact your retail offers is crucial, and comparing offers can lead to significant savings. Best Electricity Plans & Retailers in Australia 2026: Save Up To $447 Annually

As Australia continues its transition, the ability to efficiently move power between states becomes paramount. Marinus Link represents a significant investment in this future, promising a more resilient and cost-effective energy system for millions of Australians. For homeowners with solar and batteries, improved grid stability and connectivity can indirectly enhance the value proposition of their systems by creating a more robust market for renewable energy. Unlock $1,000+ Annual Savings: Best Electricity Plans for Australian Solar & Battery Owners in 2026

Impact on Your Energy Bill

The forecast wholesale price reductions of AU$15/MWh in Tasmania and AU$17/MWh in Victoria are significant. While wholesale prices do not directly translate to identical retail bill reductions due to network charges, environmental schemes, and retailer margins, a sustained decrease in wholesale costs typically flows through to consumers over time. The project aims to put downward pressure on power prices, providing a long-term benefit for households and businesses in both states. Understanding the components of your electricity bill can help you track these changes. Your 2026 Electricity Bill: Demystifying Tariffs, Charges & Savings up to 10.7%