Looking at this website
https://www.emi.ea.govt.nz/Retail/Re...dr=ALL&_si=v|3
it appears that residential solar is growing quite quickly year on year. As is industrial and commercial solar (play around with the settings to see).
In other countries, high levels of solar generation are linked to the "duck curve" where power demand during the day drops drastically as solar output reaches its peak. I've heard power spot prices during this period of the day can become very low. If retail power prices continue to rise while solar pv cost falls I would expect this uptake trend to accelerate.
Currently solar output in NZ is low, but if the current trends continue it may not be this way for long. With this in mind I think hydro dams are the superior asset for a gentailer to have, as it can store energy behind the dam walls during the day and release it at night when prices are more favourable.
Daily power demand fluctuations could be made more extreme if EV's become more widespread and are charged at night, allowing for even bigger price fluctuations.
I'm not really an expert on this sort of stuff and would love to hear what you guys think about this :)