Electricity generation is running right on the line with risk outweighing residual power.  

Grid operator Transpower is running frequent assessments of the power situation and so far, this chilly morning is continuing to pose a threat. 

It's asked households to limit unnecessary power use at least until 9am by turning off lights and heaters when not needed. 

Chief Executive Alison Andrew told Mike Hosking that Transpower's trying to manage about 140 megawatts of controllable load to help maintain supply.  

She says the generators have put every possible bit of plant on to generate. 

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