This is entirely off-topic; But you've misread that table. those are the stats for the north island, The total split is actually:

57% hydro, 16% gas, 16% geothermal, 5% wind, 4% coal. As an aside, the South Island generates 98% of it's electricity via hydro, so if he's in the south island it would be fair to say his PC is powered entirely by hydro.