Snowy Hydro says work on a major part of its multibillion-dollar pumped hydro project remains halted after the collapse of a tunnel, adding to concerns the venture will face further lengthy delays.
The commonwealth-owned power giant last month announced a “surface depression” had formed above the main tunnel at the Tantangara site of its Snowy 2.0 project. At the time, it said tunnelling was continuing and that the integrity of the tunnel “has not been compromised”.
However, a Snowy Hydro spokesperson told Guardian Australia the tunnel boring machine (TBM), dubbed Florence, was now “temporarily paused” while plans to remediate the collapsed area are finalised.
“Across the project, and as anticipated, the ground conditions encountered by the Snowy 2.0 TBMs are highly variable, ranging from soft, sandy ground to extremely hard rock,” the spokesperson said, in explaining why the drilling had stopped.
She declined to detail how much of the 17km tunnel had so far been dug, and how long Florence would likely be stalled.
Snowy Hydro waited until late last year to inform the Australian Energy Market Operator (Aemo) that the project would be delayed a year until 30 December 2027. The company still states on its website that the first power is expect to be supplied in 2025.
The project aims to link two existing Snowy reservoirs by tunnels up to 27km in length.
A spokesperson for the climate change and energy minister, Chris Bowen, said Snowy Hydro had advised the government about the tunnel issues but said it was the latest hitch inherited from the previous Turnbull-Morrison government.
“We will continue to work with the new CEO [Dennis Barnes] and the Snowy team to ensure Snowy 2.0 plays a key role in supporting the growth of renewable energy using its large-scale energy storage to provide clean, reliable and affordable electricity on-demand over sustained periods,” the spokesperson said.
“The Albanese government is extremely disappointed that the Coalition hid delays to Snowy 2.0 while in government, which have now been captured in the latest Aemo report.”
Bowen’s opposition counterpart, Ted O’Brien, said the delays were linked to more global problems.
“It’s clear that Snowy 2.0 has not been immune from supply chain shocks experienced across the world,” O’Brien said.
Bruce Mountain, head of the Victoria Energy Policy Centre, said the length of the tunnels and the terrain made the project “just a crazy, risky project”, as now being demonstrated by the delays, Mountain said.
Another formidable challenge will be to build the extra transmission needed to carry power to Sydney in the north-east and Victoria to the south, he said, noting the first of several court cases against the connections will start next week.
Should the project be delayed significantly, or even cancelled, regulators will need to scramble to find alternative storage operations for the national electricity market. Smaller-scale batteries would likely be the quickest option to build, Mountain said.
Andrew Thaler, a local resident whose property is next to a plant making 7-tonne concrete segments meant to line the tunnels, says the impacts of the stalled drilling are evident.
“All they are doing is stockpiling concrete, and they’re running out of room,” Thaler said.
