[paranoidrobot]

HVDC systems don't do too well in high temperatures. One thing the Nullabor has in spades is high temperatures.

Why would we go to all the expense to build a long distance HVDC link for that, anyway? WA's grid has very different capacity demands from the NEM grid for the east coast. The difference in populations (and energy needs) is huge.

Makes a ton more sense to invest in energy storage systems on each side than to dump tens of thousands of tons of copper in the ground to build a pointless link.