Comment by morepork

The current HVDC link has had a lot of upgrades from the original 600MW to 1200MW now, and there are proposals to upgrade it further, but not nearly to the scale you suggest, as there just isn't the need for such levels of transmission.

Unless there were plans for major new hydro schemes in the South Island there's no particular reason not to just build new generation in the North. There is ample wind and geothermal in the North Island.

This would all change if the Tiwai Pt aluminium smelter were to close as that would leave a huge amount of generation that would need to go north to be used.