Transpower is warning that New Zealand needs to bump up electricity generation between 5pm and 7pm tonight to avoid power grid problems.
The national grid operator said that generation was less than 200 MW over that period and advised that electricity companies needed to "increase energy and reserve offers".
The notice to power companies said that "if the situation worsens we may have insufficient generation to meet demand and cover reserves for a contingent event."
Last week, Transpower asked for more power to be generated to avoid disruption to Kiwis' electricity supply.
And the week prior it issued a nationwide warning notice - revealing there was a risk of insufficient power generation and reserve to meet the country's demand.
At the time Transpower chief executive Alison Andrew said the grid emergency was due to losing generation from three sources - including a Contact Energy power station, Genesis' power station in Huntly and a drop in available wind generation.