This pumped hydro energy storage map of Australia was done by...

This pumped hydro energy storage map of Australia was done by the Australian National University.

https://openresearch-repository.anu.edu.au/bitstream/1885/142579/1/PHES%20Atlas.pdf

Apart from identifying suitable locations, it also gives details about the physical requirements that sites will need.

Above all else, it would seem that head is the most important.

What is head?

Head is the height difference between where the water enters into the hydro system and where it leaves it, measured in metres. Typically this could be the height of a weir at the turbine entrace or if the site is undeveloped it would be between where the hydro intake screen would be and where the water discharges from the turbine and returns to the watercourse.

http://www.renewablesfirst.co.uk/hydropower/hydropower-learning-centre/what-is-head/

From the ANU atlas:

Good PHES sites have the following characteristics:

• Large head: 300-600 m heads are desirable. Doubling the head doubles energy and power but often does not double the cost. For comparison, the existing Tumut 3 PHES system has a head of 150 m

• Gentle slopes behind the dam wall: so that a modest wall can impound a large amount of water• Large water volumes: in our modelling we generally require a minimum of 1 GL, which roughlycorresponds to 1 GWh of stored energy (for ~400 m head)

• Large volume of stored water compared with the volume of rock required for the dam. That is, alarge water/rock ratio. A ratio above 10 is desirable, and preferably much higher

• Short and steep connecting pressure pipes/tunnels between upper and lower reservoirs tominimise length/cost

• Minimum conflicts with indigenous, environmental, social, heritage, urban, agricultural and landmanagement aspects

• Appropriate geological characteristics

• Good access to roads and high voltage power lines

• Good access to water

Looking at the pics of the Kidston site, there ain't no way they are going to get 300 to 600 metres of head.

However, they can improve the site that they have by the addition of a turkey's nest around the upper reservoir.

"A turkey nest reservoir entails a continuous earth wall around most of the impoundment."

In fact, that is what the ANU study, suggests they will do.

The three common types of site are:

• Turkey nest: the upper reservoir is built at the top of a flat hill. Earth and rock is scooped from the interior to create a continuous earth wall perhaps 20 m high;

• Head of gully: an earth wall is placed across a small gully near the top of a mountain to impound water. This design has the advantage that the wall length and hence cost is reduced compared with a turkey nest reservoir;

• Old mine sites: the mining pit can form the lower reservoir, and the upper reservoir can be a turkeynestreservoir located near the edge of the pit. Anexample is the proposed 250 MW Kidston PHES project in an old gold mine in north Queensland [8].