Officials figures indicate that the wind energy sector did not produce enough power this winter.
A combination of officially encouraged power savings, timely rain and heavy production by fossil fuel stations has helped reduce the risk of serious energy shortages for the rest of the winter.
However, official production figures show a large number of still days meant wind energy failed to play its part.
During some weeks in autumn, Meridian Energy's Te Apiti wind farm produced only one sixth of its installed capacity.
Energy experts say the problem could intensify in future dry autumns if the Government presses ahead with additional renewable energy schemes.