SNOWY 2.0: THE CRITICAL STORAGE ENABLING OUR RENEWABLE ENERGY FUTURE

By Snowy Hydro Ltd.

Sometimes you have to move mountains to achieve big ideas. In the case of Australia's Snowy Mountains Scheme, that was true when the visionary project was first being delivered. It’s just as true in 2023, as Australia stands at the precipice of enormous changes to our energy market.

The original scheme, described as one of the engineering wonders of the modern world, involved tunnelling through rock to create 145km of interconnected tunnels and 80km of aqueducts. It was an awesome feat of engineering that unlocked wealth, along with regional and economic development in Australia.

In 1949, on the heels of WWII, local crowds and government officials gathered in the mountain town of Adaminaby to celebrate the Scheme’s first blast. As rain and light snow cleared, Australia’s prime minister Ben Chifley proclaimed that Australia was “on the threshold of a new era of great industrial and rural development”.

Australia was being reshaped, and post-war reconstruction required new thinking and ambitious projects. European migration, the introduction of unemployment programs and a renewed focus on economic diversification kicked off a period of urbanisation and industrialisation. Our growing cities needed power, our inland cropping and grazing country needed reliable irrigation and the Snowy Scheme became a nation-building initiative.

The new era

Fast forward to today, as we embark on another great era of transformation and innovation, this national icon, through Snowy 2.0, is again at centre stage.

Some of the challenges are new, like decarbonising our economy and reaching net zero, while maintaining reliable baseload power, but all require similar levels of ambition and ingenuity. Australia is poised to change the way we generate energy, the minerals we mine and the goods we manufacture as well as the vehicles we drive.

Key to future success is our electricity supply. We must have enough to meet growing demand and ensure its reliability.

The Australian Energy Market Operator (AEMO) has made the challenge clear. It anticipates in its 2022 Integrated System Plan that we will add nine times the amount of wind and solar to the National Electricity Market (NEM) by 2050, and we will need an additional 45GW of storage of all types to keep the lights on.

This means that the NEM is rapidly undergoing a fundamental transformation, from a centralised grid, underpinned by a relatively small number of larger and older fossil-fuel driven generators, to a more complex, decentralised system of many smaller wind, solar, storage and peaking gas units.

As the NEM evolves to include far more renewable generation, Snowy 2.0 will act as an enormous battery, storing excess renewable energy and then filling a critical need by generating power to smooth out the peaks and troughs of volatile, intermittent renewable generation. Snowy 2.0, which will link the existing Tantangara and Talbingo reservoirs through 27km of tunnels and a new underground power station, will unlock the ability to run for seven days continuously before recharging. It’s proven technology, using reversible pump turbines to generate when demand is high and then pump the water back to the upper reservoir (Tantangara) when there is an excess supply of renewables in the system. This ‘deep storage’ capability is critical to providing reliable, clean, renewable power to approximately 500,000 Australian homes simultaneously, as well as businesses and industry. It will help provide energy security, especially in periods of wind droughts or extended overcast conditions that impact solar generation.

Unlike conventional batteries, Snowy 2.0 will provide this storage for at least 100 years using existing dam infrastructure, and without requiring a substantial new footprint, creating hazardous waste or unnecessary environmental pollutants.

The project is also doing its share of the heavy lifting to achieve Australia’s emissions reduction targets. As the largest committed renewable energy project in Australia, Snowy 2.0’s 2,000MW of fast-start generation and 350,000MW/H of energy storage will significantly reduce Australia's dependence on fossil fuels. Further, it will have a multiplier effect as visionary storage assets like Snowy 2.0 are required to unlock investment in more renewable projects.

Of course, Snowy Hydro is already underpinning industrial-scale clean energy initiatives, by purchasing more than 5.4 terawatt hours annually (more than 1,650MW of installed capacity) of renewable energy from wind and solar projects through long-term offtake contracts. Combining cost-effective solar and wind energy with Snowy Hydro’s on-demand hydro-electricity allows us to offer our customers firmed, affordable, reliable and clean energy.

Snowy 2.0 will also help manage the baton hand-off from the grid’s aging thermal workhorses to the flexible resources of Australia’s energy future.

However, delivering this vision and addressing the major challenges of the energy transition do not come with a simple snap of the fingers.

Snowy 2.0’s resilient future

As was the case with the original Scheme and with every other major piece of infrastructure, delivering ambitious projects like Snowy 2.0 require determination and resilience. There have been challenges to overcome, including some – like devastating bushfires, along with the COVID-19 pandemic and its associated resourcing and supply chain impacts – that could never have been anticipated.

Fortunately, the project’s complexities are being actively managed by an expert and experienced team. As 2,200 workers across multiple active worksites navigate sensitive mountainous terrain, we are drawing on world-leading engineering design and construction expertise, along with the deep knowledge embedded in Snowy’s DNA, curated over decades by operating the Snowy Scheme responsibly in Kosciuszko National Park.

Snowy 2.0 is making solid progress across key work fronts, despite the complexities of this renewable energy mega project. Tunnel boring machine (TBM) Lady Eileen Hudson has completed the 2.85km main access tunnel down to the site of the underground power station and is now being prepared to excavate the 6km tailrace tunnel to feed into Talbingo Reservoir. TBM Kirsten has almost completed the adjacent 2.9km emergency, cable and ventilation tunnel, where it has also reached the location of the power station cavern. We are also excavating a series of cross tunnels and passages and will shortly commence the drill and blast excavation of the power station cavern complex – a major milestone. TBM Kirsten will soon be modified to begin excavating the very steep inclined pressure shaft. This process will set a new global tunnelling standard, with the TBM progressively installing a lining of special concrete segments designed to withstand enormous water pressures.

Excavation of water intakes at Talbingo and Tantangara is progressing well.

Meanwhile, in the headrace tunnel at Tantangara, TBM Florence hit soft and unstable ground, conditions exacerbated by persistent wet weather in 2022. The TBM has been temporarily halted approximately 150m from the tunnel entrance, as the project team works on stabilising approximately 15m of weak material ahead. Drilled cores show the TBM will move forward into harder rock, after which we expect normal tunnelling can resume. Importantly, the integrity of the tunnel, which is supported by a concrete lining and steel ribs, has not been compromised, and nor has the capacity of the TBM.

Our team of world-class engineers, construction, technical and supporting services workers are firmly focused on delivering this project safely and effectively, while minimising its impact on the surrounding environment.

As Snowy 2.0 progresses through major milestones and continues to make an enormous contribution to the Snowy Mountains regional economy, we look forward to writing a new chapter in the Snowy’s rich history. From an early dream to move water from east to west and to harness the power of Australia’s mighty rivers, the deep storage capability being built now as part of our integrated energy business will reduce volatility in the market, support reliability and bring down power prices for Australian families and businesses.

Just as the original Scheme changed our nation for the better, Snowy 2.0 will power Australia’s future, keeping the lights on and providing for the energy needs of generations to come.