grid parity, page-19

Indeed there is alot wrong MJ :)

If Southland has a floor area of 129071 m². ...

Half of that is 64535 m2 not 645,355 m²

Applying your remaining assumptions, thats about 56 units.

But using the peak wattage x 24 is wacky, giving you 268 KwHs per 24Hr day? That figure doesn't look right either given that you say that the annual draw is 1760 KwHs.

For simplisity why not just divide the surface area by the annual draw?

64535/1760 = 36.6 units