Hydro power brings reliability to renewables

Massive problems have beset the Snowy 2.0 pumped storage hydro program, an ambitious renewable energy project intended to become a vast reservoir of stored energy. One of the 2000-tonne tunnel-boring machines, known as Florence or Flo, recently got stuck in very hard rock and high-pressure water jets were deployed to set the machine free. Last year, Flo spent months bogged in soft ground. The Snowy 2.0 budget has blown out to $12bn, but the project’s value has also increased in a changing electricity market.

Hydropower has been a reliable source of renewable energy in Australia for decades, providing around 6.4 per cent of total energy supply in 2020, according to the Clean Energy Council. Although Australia is largely flat and often very dry, more than 120 hydro power stations operate across the nation, and the Snowy Mountains Hydro-Electric Scheme is the largest.

When Snowy 2.0 is finished, possibly by 2028, the latest addition to the Snowy Scheme will be the largest pumped hydro operation in Australia and the nation’s biggest renewable energy project – a giant “water battery” in the mountains of NSW.

Renewable power will be used to pump water from a large reservoir up a steep incline to another large reservoir. When hydro energy is needed, at times of peak power usage after the sun sets, or after long periods of cloudy or windless days, the water can be released to rush back down the incline though turbines and create energy.

“The tunnelling geology is quite challenging,” says Snowy 2.0 chief operating officer Roger Whitby. “Big projects, and we’re talking a mega-project in Snowy 2, always have their challenges, so we have to deal with them.” Despite the obstacles, the project has moved forward, he adds. “In terms of progress, I think the number is 57 per cent through the project. We’re a long way in.”

Now the scramble is on across Australia to get pumped hydro projects constructed for the coming demand for renewables power as the nation transitions to net zero. There are already four operational pumped hydro projects – in Shoalhaven, NSW, Tods Corner in Tasmania, Wivenhoe in Queensland and, by far the largest, Tumut 3, which has been running for 50 years as part of the broader Snowy Hydro scheme in NSW.

According to the US department of energy, pumped storage hydro projects were established in Italy and Switzerland in the 1890s and first used in the US in 1930. The US now has 43 pumped storage hydro plants which account for 96 per cent of the nation’s utility-scale energy storage.

“Pumped hydro is not very new, in a sense it’s an old technology and we’re applying it at a scale that’s bigger than utilised in Australia before, but the technology itself is well-proven,” says Whitby.

“Snowy’s been operating pumped storage for over 50 years. In terms of operation, it’s pretty straightforward.”

The combination of Tumut 3 and Snowy 2, he adds, will be one of the largest pumped storage complexes. The project will provide energy security to millions of consumers.

Currently under construction, as well as Snowy 2.0, is the much smaller Kidston project in Queensland. Other pumped hydro projects are in the planning stages, with potentially two new pumped hydro storage projects in Queensland, at Borumba, about 160km north of Brisbane, and the massive Pioneer-Burdekin project west of Mackay.

Queensland Hydro CEO Kieran Cusack says pumped hydro energy storage is proven, reliable, and mature technology and “unquestionably the right technology” for the transition to clean power.

“The proposed Pioneer-Burdekin project would be the most powerful pumped hydro in the world, while maintaining a relatively small footprint,” he says. “The proposed site has excellent potential for pumped hydro due to 700m of elevation between upper and lower reservoirs and short tunnel lengths of approximately three kilometres, which is significantly different to Snowy 2.0 where the distance between reservoirs is about 27km.”

The Australian