The electricity industry is manoeuvring to avert a possible electricity supply crunch that has been signalled for April.
The warning comes from a special advisory body headed by former Treasury Secretary Graham Scott.
It says insufficient electricity was produced by gas- or coal-fired power stations six times last winter, because full hydro lakes had meant electricity prices were too low to make it worth firing up the boilers.
As a result, electricity that should be kept in reserve had to be dipped into, leaving not enough spare capacity to meet an accidental outage.
Since then, an ad hoc body made up of Transpower, the Electricity Commission and the major generators has been trying to fix the problem, by improving information flows so generators can make decisions faster.
The risky period will only last for two months, after which special fast start-up generators in Taranaki will be ready.
In a separate concern, the advisory body said in December that the overall supply of electricity could be tight by 2012.