Transpower had warned of a heightened risk of power shortages before 8am on Thursday.
Photo: 123rf
The national grid operator issued the New Zealand-wide emergency warning over a power shortage.
The alert was posted after one of Contact Energy's gas turbine units at Stratford failed to start, Genesis Energy reported a fault at its Huntly plant and the wind dropped from a forecast 170 megawatts to just 30.
In an update just before 9.30am it said the grid emergency had ended and load management could be returned to normal.
It said no-one was disconnected during the grid emergency and the system worked as intended.
Chief executive Alison Andrew said Transpower worked with lines companies to get through the morning peak and the grid emergency was over by 9.30am.
She said Transpower was confident there will be enough capacity to cope with the evening peak in demand.
Earlier, its system operator advised there was a risk of insufficient generation and reserve offers to meet demand and provide coverage in a major N-1 event.
Transpower asked people to reduce their power consumption if possible, by turning off non-essential lights and delaying charging mobile and laptop devices.
It was working with local lines companies to manage controllable load by turning off hot water systems, the spokesperson said.
The Electricity Authority said this morning's power generation emergency was well handled by Transpower.
The authority's general manager of legal monitoring and compliance, Sarah Gillies, said she was happy with how the matter was dealt with.
"As the regulator we obviously work really closely with Transpower and the way they handled the matter this morning was exactly the way we needed it to be handled so we're very happy with the way it went."
Contact in the dark
Contact Energy said it does not know why its gas turbine generator at Stratford failed to start up around 7am today.
Around the same time, Genesis Energy reported a fault at its Huntly plant and wind speeds dropped .
Contact's chief generation officer, John Clark, said there are two 100-megawatt fast start peaker units at Stratford, but one of them has been out of action since it broke last year and a replacement is still yet to be sent from Europe.
Clark said Contact does not know why the remaining operational unit did not start.
Contact brought on extra supply from its other power plants.