[robocat]

Can your reference some live data?

I had a look at https://www.transpower.co.nz/power-system-live-data

And that showed hydro was running at less than 50% of capacity for one relevant data point.

I am guessing the data series of hydro usage versus capacity is available for NZ. Finding out the constraints and understanding them is more difficult.

Your point of maximum capacity may be true, but we are talking usual daily usage (duck graph) and whether solar can use hydro for that.

In think you are arguing about occasional peak network capacity (e.g. heat wave) which is an outlier and you retain power stations with extremely low utilisations for those abnormal peaks (and ignore green issues).