Melbourne University Climate and Energy College senior adviser Simon Holmes à Court said that modelling for the National Energy Guarantee (NEG) assumed Tasmania’s “Battery of the Nation” pumped hydro project would not proceed.

He said 23 academics from 11 universities across Australia wrote to the country’s energy ministers last week to request access to the modelling, which was provided last Friday.

Mr. Holmes à Court said he was surprised to discover a lot of promised projects were not supported by the modelling.

He said of six or seven pumped hydro projects planned throughout Australia, only Snowy Hydro 2.0 was expected to proceed.

“The Battery of the Nation project, which very much presents a lot of opportunities for Tasmania, the modelling assumes that project’s not going to go ahead,” Mr. Holmes à Court said.

So-called pumped hydro — a long-established storage technology also proposed for the Hoover Dam, outside Las Vegas — could be a bulwark against the crippling outages that have dogged southeastern Australia in recent summers. While $40 billion has been invested in solar and wind projects in the past decade to replace retiring coal-fired generators, energy storage systems are needed to ensure sufficient supply during peak demand.


Energy Security

While pumped hydro costs more to produce per kilowatt than coal or solar power, the security that it adds to electricity grids increasingly reliant on renewable energy makes it invaluable. Also, the long lifespan of pumped hydro means these projects can provide a return on investment for a century or more, compared with a few decades for other sources.

For Tasmania, pumped hydro promises to double the island’s clean energy capacity to 5 gigawatts and feed an ailing national grid through a proposed undersea cable. Still, doubts linger over the project’s economic viability — with the financial model yet to be decided — and feasibility, after an existing cable broke two years ago.

“Pumped hydro is the technology of choice for large-scale energy storage,” said Gwynne, project director for state-owned Hydro Tasmania. “Nobody in the private market wants to go anywhere near building a new coal-fired generator. But the fact that there are some elements of our political system that still believe fossil fuels are the future gives us the opportunity to talk about why we don’t think it’s a good idea.”


China, Switzerland

Pumped hydro plants have been built in China, Switzerland, Israel, and France amid a rapid rollout of intermittent renewable power. About 6.2 gigawatts of pumped hydro plants were commissioned worldwide in 2016, dwarfing the 688 megawatts of lithium-ion batteries that entered service, according to a 2017 report by Bloomberg New Energy Finance.

Prime Minister Malcolm Turnbull is one advocate. The former Goldman Sachs banker has backed transforming as many as 14 aging Tasmanian hydroelectric stations into modern-day pumped plants after a series of highly publicized blackouts and escalating electricity costs angered voters. A federal election is due to be held by next May.

Implementing the proposed projects would more than quadruple Australia’s pumped hydro storage capacity to 11.5 gigawatts, the world’s fourth-largest, according to the DOE Global Energy Storage Database. It would also provide a substantial buffer to balance volatility in the supply of wind and solar energy to the national grid.

“For Australia, pumped hydro can be a good option for managing the reliability of the grid,” said Bikal Pokharel, a research director at Edinburgh-based energy consultancy Wood Mackenzie. “However, the viability of pumped storage hydro will come down to the economics of the plant. Similar to the cost of charging a battery, there is a cost of pumping back hydro.”


‘Huge Opportunity’

“It is a huge opportunity,” Turnbull said of Tasmania’s pumped hydro potential during a visit to the state last year. “The energy market is progressing, the evolution of it is very rapid, so I think the sooner we can see the opportunities here in Tasmania, the better.”

The prime minister is also planning to add pumped hydro to the existing Snowy Mountains scheme, located in the highlands between Sydney and Melbourne. That plan requires the construction of a 27-kilometer tunnel and will cost from A$1.9 million to A$2.25 million per megawatt to build, compared with estimates of A$1.05 million to A$1.5 million per megawatt for the Tasmanian plants.

Despite Tasmania’s cost advantage, doubts linger about the plan’s viability. The state almost ran out of water in 2016 during a drought some scientists blamed on climate change and had to turn to diesel-powered generators after its existing undersea cable to the mainland energy grid broke.