The Snowy 2.0 project has reached a critical stage as construction advances on Australia’s largest committed renewable energy project. Snowy Hydro reported 73% overall completion as of March 31, 2026. However, a June 2026 Australian National Audit Office review highlighted continuing schedule and cost-management challenges.
The pumped hydro project will connect the Tantangara and Talbingo reservoirs through approximately 27 kilometers of tunnels. It will also feature a new underground power station with 2,200MW of generation capacity.
Recent developments have therefore shifted attention from the project’s scale toward its delivery timeline and final cost. Snowy Hydro is reassessing costs while contractors continue major underground construction activities.
Snowy 2.0 project advances major underground construction
The project has continued significant tunneling work during 2026. In May, Webuild announced that tunnel boring machine Lady Eileen Hudson broke through the underground cavern complex.
That breakthrough represented a major construction milestone for the underground power station. The cavern complex forms a central component of the project’s generation infrastructure.
Furthermore, the project’s construction program continues across several underground and surface work areas. Future Generation Joint Venture has also continued procuring specialist packages for tunnel lining and concrete works.
Recent tender activity includes formwork, reinforcement and concrete placement packages for final tunnel lining. Other packages cover hydro-demolition and remedial works around project structures.
The construction program therefore remains active despite the project’s broader schedule pressures.
The Australian National Audit Office reported 73% overall project completion at March 31. However, it also identified persistent challenges involving geology, safety stoppages and industrial relations.
Snowy 2.0 project faces cost and schedule pressure
The project’s financial position remains one of its biggest challenges following several cost revisions. Snowy Hydro increased the estimated project cost to $12 billion during the 2023 reset.
By March 31, 2026, Snowy Hydro had spent $11.1 billion on the project. The company was also reassessing the remaining cost required for completion.
The Australian National Audit Office also examined contractor management and project governance. Its June report found shortcomings that affected delivery oversight and performance management.
Meanwhile, Snowy Hydro has faced difficulties aligning contractor schedules with contractual completion requirements. The Future Generation Joint Venture submitted an acceleration program in March 2026.
However, Snowy Hydro objected to the proposal in April because it did not meet contractual requirements. The company also cited forecasts indicating further delays.
The project’s commercial operation date remains under pressure. Earlier planning targeted December 2028, while subsequent forecasts indicated later completion trajectories.
Additionally, a detailed cost review announced by Snowy Hydro has attracted further scrutiny. By August 2026, the federal government had still not received the completed review.
Snowy 2.0 project reinforces Australia’s storage expansion
Despite those challenges, the project remains central to Australia’s long-term energy storage strategy. Snowy 2.0 will provide pumped hydro storage capable of supporting renewable generation for extended periods.
The project will add 2,200MW of generation capacity to the Snowy Scheme. Its reservoirs and tunnels will allow the system to shift electricity between periods of surplus and peak demand.
The development also illustrates the enormous infrastructure requirements behind long-duration energy storage. Its underground works extend for kilometers through difficult mountainous terrain.
Meanwhile, Australia continues developing large battery storage facilities alongside pumped hydro. One major example is the Hanworth BESS, a proposed 1.2GW/4.8GWh facility in New South Wales.
Octopus Australia and Enervest submitted the Hanworth project for federal environmental assessment in August 2026. The developers propose connecting the facility to Transgrid’s Bannaby transmission infrastructure.
Unlike Snowy 2.0, Hanworth BESS would use electrochemical batteries rather than pumped hydro infrastructure. Its proposed four-hour storage duration would complement longer-duration storage assets across Australia’s electricity network.
Snowy 2.0 therefore remains a major test of Australia’s ability to deliver complex long-duration energy infrastructure. Its continued construction will determine when the country can fully realize the project’s promised generation and storage benefits.
Snowy 2.0 Underground Battery project construction scope
The project expands the historic Snowy Hydroelectric Scheme through reversible pumped hydro technology. It functions as a large-scale energy storage system rather than a conventional plant. Therefore, it stores excess renewable electricity and dispatches it during peak demand periods.
Engineers are installing six reversible pump-turbines inside the underground powerhouse. These turbines generate electricity when water flows downward and pump water uphill during surplus supply. As a result, the system continuously cycles water between reservoirs to balance grid demand.
Moreover, the 27 kilometers of tunnels form the backbone of the system. These tunnels enable controlled water transfer between the two reservoirs. Without them, the integrated storage system would not operate effectively at this scale.
Snowy 2.0 Underground Battery project capacity and scale
The project will deliver 2,200 MW of generation capacity alongside 350 GWh of storage. This capacity places it among the largest energy storage developments globally. In addition, it will supply enough electricity to power approximately three million homes for up to a week.
The scale aligns with projections from Australia’s energy market planning frameworks. These projections highlight the growing need for dispatchable storage as renewable penetration increases. Therefore, the project directly addresses long-duration storage gaps in the national grid.
Furthermore, the infrastructure is designed with a lifespan of up to 150 years. This long-term outlook positions the project as a multi-generational energy asset. It also reinforces its role in supporting the transition to a low-carbon electricity system.
Grid transformation driven by the construction project
The project will significantly enhance grid reliability across Australia. It provides rapid-response generation during supply shortages and supports system stability during renewable variability. Consequently, it reduces dependence on fossil-fuel-based peaking plants.
Additionally, the project allows better utilization of wind and solar generation. Excess electricity generated during low demand periods will be stored instead of curtailed. Later, the stored energy will be released when demand increases or renewable output declines.
Snowy Hydro expects the project to reach completion by the end of 2028. Once operational, it will become a central dispatchable energy source within the national electricity market. Therefore, it will play a critical role in balancing supply and demand across interconnected regions.
The project also attracts global attention due to its engineering complexity and strategic importance. Its scale, depth, and storage capacity position it as a benchmark for future long-duration energy systems. As a result, it is widely regarded as a model for integrating renewables with large-scale storage infrastructure.
Additionally, the broader energy storage landscape in Australia continues to expand, as seen in the Summerfield Battery Project, which highlights parallel investment in grid-scale battery infrastructure supporting renewable integration.
Project Fact Sheet
Name: Snowy 2.0.
Type: Pumped hydro energy storage and generation project.
Location: Snowy Mountains, New South Wales, Australia.
Developer and owner: Snowy Hydro Limited.
Generation capacity: 2,200MW.
Storage capacity: Approximately 350,000MWh.
Main reservoirs: Tantangara and Talbingo.
Underground tunnel network: Approximately 27 kilometres of power-waterway tunnels.
Main power infrastructure: Underground power station.
Current reported completion: 73% as of March 31, 2026.
Reported expenditure: $11.1 billion as of March 31, 2026.
Current estimated project cost: Approximately $12 billion, subject to reassessment.
Original cost estimate: Approximately $6.1 billion following early works.
Construction contractor: Future Generation Joint Venture.
Major contractors: Webuild, Clough and Lane.
Target operation: The project continues to face schedule pressure against its original December 2028 target.
Design life: Approximately 150 years.
Primary purpose: Long-duration electricity storage and renewable energy generation.
Strategic role: Support Australia’s renewable energy transition and grid reliability.
Project Team
Project Owner: Snowy Hydro Limited
Engineering, Procurement, Construction Contractor: Future Generation Joint Venture
Joint Venture Partners:
- Webuild (Italy)
- Clough (Australia)
- Lane Construction Corporation (USA)
Tunneling Technology Provider: Herrenknecht AG
Transmission Network Integration: TransGrid
Government Stakeholder: Australian Government
Engineering Scope Includes:
- Tunnel boring and underground excavation
- Powerhouse cavern construction
- Pump-turbine installation
- Hydraulic and electrical system integration
Workforce: Thousands of engineers, geotechnical specialists, and construction workers
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