A new ANU study says there are more than enough potential pumped hydro sites to power the nation.

Experts have completed an audit of 22,000 potential sites across Australia for pumped hydro energy storage, which can be used to support a secure and cheap national electricity grid with 100 per cent renewable energy.

Pumped hydro storage can be used to provide the hallowed baseload reliability that would be needed to underpin an energy system based on less reliable generators like wind and solar farms.

The ANU team was able to identify far more places than are actually needed by widening their consideration of suitable sites to include places like expired mining pits.

The short-term off-river pumped hydro energy storage (STORES) sites combined had a potential storage capacity of 67,000 GWh.

Australia needs only about 450 GWh of storage to support a 100 per cent renewable electricity system.

Lead researcher Professor Blakers from the ANU Research School of Engineering says a pumped hydro system could solve some of the problems that face the grid today.

“Fast tracking the development of a few of the best sites by 2022 could balance the grid when Liddell and other coal power stations close,” he said.

“Pumped hydro storage, including Snowy 2.0, can be developed fast enough to balance the grid with any quantity of variable wind and solar PV power generation, including 100 per cent renewable energy.

“We found so many good potential sites that only the best 0.1 per cent will be needed. We can afford to be choosy.”

All the outlined sites could contain pairs of reservoirs at different altitudes, typically ranging from 10 hectares to 100 hectares, in hilly terrain and joined by a pipe with a pump and turbine.

To power the pumped hydro system, water is pumped uphill when wind and solar energy is plentiful, and electricity is available on demand by releasing the stored water through a turbine.

Co-researcher Dr Matthew Stocks said that off-river pumped hydro storage typically delivered maximum power for five to 25 hours, depending on the size of the reservoirs.

“Like all hydro power, it can go from zero to full power in about one minute,” said Dr Stocks from the ANU Research School of Engineering.

“Annual water requirements would be much less than half that of the current fossil fuel system because wind and PV do not require cooling water.”

Co-researcher Mr Bin Lu said all of the potential STORES sites were outside national parks and urban areas, and each site had a storage potential range of 1-300 GWh.

“Pumped hydro - which accounts for 97 percent of energy storage worldwide - has a lifetime of 50 years, and is the lowest cost large-scale energy storage technology.”

The Australian Renewable Energy Agency (ARENA) provided $449,000 to support the ANU-led study.

Maps showing the locations of potential STORE sites and a report on the findings are available here.