Does anyone know if there is adequate transmission capacity for 500MW from Cooper Basin to a viable customer base or will this have to be built?

No doubt it will need to be built.

Its hard to find a map of the grid - GENI used to have one but the ESAA seems to have made them take it down.

http://www.geni.org/globalenergy/library/national_energy_grid/australia/...

You can buy one for $72 though...

http://www.esaa.com.au/index.php?option=com_phpshop&page=shop.browse&cat...

Any transmission facilities will have to be built. The initial customer could be the BHP-B Olympic Dam mine and copper smelter which has huge electrical requirements which would require a significant expansion of the SA electrical generation capacity + grid.

The 15,000 tonnes per year of Uranium +(silver + gold) is nice earner on the side of the major play - copper.