Fourth tunnel boring machine to ensure Snowy 2.0 extension of Snowy-Hydro scheme hits mark

After meticulously considering our options against our improved understanding of the geology, a new tunnel boring machine is the best way forward for this key green energy project.

Part of the massive Snowy 2.0 project in the Snowy Mountains.

Construction of the Snowy 2.0 extension of the Snowy Hydro-electric Scheme is now almost 60 per cent complete. This is significant progress in the face of the inevitable complexities that have arisen in what is one of the world’s most significant and challenging megaprojects.

Snowy 2.0 is the critical centrepiece of decarbonising Australia’s energy market and will help reshape Australia’s economy, serving Australians for the next 150 years. The project has already created more than 3000 jobs and is injecting significant investment into regional communities.

It has not been without its ­setbacks. The widely publicised ­issues with Florence, one of our three tunnel-boring machines, have required flexibility. We have a new challenge ahead of us and must take action to de-risk this critical project’s delivery timeline.

Snowy 2.0 has submitted a proposed modification to the project’s existing approvals to bring a fourth tunnel-boring machine online. This is the best intervention to protect our target completion date of December 2028.

The reason a fourth tunnel borer is needed is that we now have greater information about the geological conditions we face excavating the tunnel that will connect the upper reservoir to the Snowy 2.0’s massive 20-storey underground power station, known as the “headrace’ tunnel.

A tunnel entrance at Snowy Hydro 2.0.

We’ve known since the 2017 feasibility study that the headrace tunnel passes through a fault zone, so this is not a surprise, and following the project reset new ground investigation methods have given us a more detailed understanding to help us overcome the initial design immaturity. The ground conditions in the area of the zone we need to tunnel through are far poorer and more variable. I’ve said in the past that we will have to take some action regarding the fault zone. After meticulously considering our options, a new tunnel-boring machine is the best way forward.

It is difficult to say with certainty whether the same action would be needed if Florence had performed as we had hoped. However, it’s likely that the fourth ­machine would still be needed.

Successfully delivering nation-building projects of this nature ­requires vision, courage, determination and persistence.

Even the original Snowy Scheme was far from smooth sailing. Now celebrating 75 years since work began and having served Australians for many decades, the scheme took a quarter of a century to build. Its delivery had to overcome significant challenges and was mired by controversy throughout construction, yet the enormous social and economic benefits it unlocked are beyond dispute.

Snowy Hydro chief executive Dennis Barnes.

Australia is in the midst of another fundamental economic transformation, this time driven by the need to decarbonise. Snowy 2.0’s incredible scale and flexibility means it is a critical centrepiece of this agenda.

Snowy 2.0 will provide 350,000 megawatt hours of deep energy storage. That’s enough to power around three million homes continuously for a week at a time when there is no wind or sunshine.

According to the Australian Energy Market Operator, Snowy 2.0 will supply the majority of the National Electricity Market’s storage needs, greater than every other storage asset combined.

There is no other energy project that comes close to this ­impact. It will provide critical energy supply insurance during extended periods of low renewable generation, precisely the kind of conditions that were experienced this winter.

Without Snowy 2.0, Australia will simply be unable to ensure the reliability and security of our electricity markets, while we switch to cleaner electricity generation.

This project is an investment for the future of our nation. It’s an investment that will underpin sustainable economic prosperity into the next century, reduce volatility in the energy market, and serve as the cornerstone for the jobs and skills essential for Australia’s energy transition.

Dennis Barnes is the CEO of Snowy Hydro.