Snowy Hydro reported significant progress on its 2.2GW Snowy 2.0 pumped-hydro megaproject in Australia, with one of its tunnel boring machines (TBM) now completing two-thirds of its second tunnel excavation.
Dubbed Lady Eileen Hudson, the TBM has advanced approximately 4km along the 6km ‘tailrace’ tunnel, which will connect the lower Talbingo Reservoir to the underground power station.
Previously, Lady Eileen Hudson had completed a 2.85km main access tunnel, which now serves as an entry route for construction teams accessing the power station site.
At the Talbingo water intake, additional progress is being made through drillling and blasting works to establish a new 700m tunnel that will connect the intake structure to the tailrace tunnel.
Situated in rugged terrain, the Talbingo intake required two years of work to excavate 570,000m3 of material, resulting in a rock face that now stands at 110m high.
Snowy Hydro CEO Dennis Barnes stated that recent months have been among the most productive for the project, with Snowy 2.0 anticipated to be the most transformative addition to the National Electricity Market (NEM) since the original Snowy Scheme.
The Snowy 2.0 project remains on schedule to be completed by the end of 2028, within its projected A$12bn ($7.9bn) budget.
Barnes said: “Snowy 2.0 will have a generating capacity of 2.2GW and an unmatched 160-hour storage capability, meaning it will be able to power around three million homes for a week.
“While batteries and gas are important to store the excess energy from the increasing amounts of wind and solar in the grid, only pumped hydro can offer the long-duration storage needed to keep the lights on and smooth energy price peaks during extended periods without enough sun and wind.”
Significant advancements are also taking place at the underground power station complex, where over 27% of the excavation for the caverns has been completed.
The installation of all 196 large brackets, necessary for the temporary construction cranes, is also finalised in the power station caverns.
Once fully excavated, the power station will be an underground structure comparable to a 20-storey, 250m-long building, positioned 800m below the surface.
At Marica, the 28m-wide surge shaft is excavated to 123m, or about half of its final depth. This shaft will function as water storage during power station start-up and provide pressure relief within the headrace tunnel upon shutdown.
TBM Florence has also made significant headway in the 17km-long ‘headrace’ tunnel, linking the upper Tantangara reservoir to the underground power station, with over 1,600m of excavation completed.
Another machine, TBM Kirsten, is advancing along the 1.6km steep tunnel that will connect the headrace tunnel to the underground power station.
A planning modification is currently being reviewed by the New South Wales Department of Planning, Infrastructure and Housing, which would enable the use of a fourth TBM to tunnel through a challenging geological fault zone.
Last month, Webuild and Clough, as part of the Future Generation joint venture (JV), the principal contractor for the Snowy 2.0 project, achieved the breakthrough at the Tantangara transition tunnel.
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