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Reliability2026-09-25· RenewEconomy

Snowy starts laying concrete foundations for massive turbines a kilometre underground

Image: reneweconomy.com.au

Snowy Hydro has begun pouring permanent concrete for the underground machine hall of Snowy 2.0, nearly a kilometre below the surface, with excavation of connector tunnels complete and crews preparing to install turbines, inlet valves and transformers. The project, which has weathered significant tunnel-boring delays including equipment wedged in rock and a fourth $75 million drilling machine deployed to complete the 17 kilometre headrace tunnel, now enters the internal fit-out phase with more than 1,400 precast concrete components scheduled for installation over coming months. All six reversible turbines have been delivered.

Where this fits

Snowy 2.0 is pumped hydro storage, the only firm, dispatchable backup Australia has built in two decades to match renewable output to demand. The project's cost, now subject to a long-delayed review Snowy Hydro has not yet released, has ballooned through construction complexity and delay. It is a data point in the wider pattern: a renewables-only grid requires massive storage and transmission investment to achieve the same reliability that firm power plant delivered at lower whole-system cost. Snowy 2.0 is necessary precisely because wind and solar are weather-dependent; it is not a substitute for reconsidering the cost and materials burden of that dependency.

What it means

Australia has committed to storage and tunnelling engineering at continental scale to firm a renewable grid. The alternative, firm generation that requires no storage infrastructure, no transmission overbuild, and no weather-dependent output variability, remains legally barred. Snowy 2.0 will eventually deliver, but the years of delay and the scale of cost escalation illustrate why dispatchable power is cheaper to build once, than to retrofit through storage.

Go deeper on the numbers

The bigger picture

Energy security is national security. This connects to the wider case at Unprepared: Australia's dependence on a strategic rival, and how ready it is for the world that is coming.

Reported by RenewEconomy. Read the original report ↗

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