I think it might be either wind power or hydro electric, but because new zeland has many rivers and reservoirs, i think it might be hydro electric power.
It is the winter solstice. T<span>he solstice that marks the onset of winter, at the time of the shortest day, about December 22 in the northern hemisphere and June 21 in the southern hemisphere. I know this mainly because I had the same question. Good luck :)</span>
One of them is specifically in September 22, 2021 and the other is in March but I’m not really sure what day specifically.
Mining hope my answer helped............
