Transpower restores circuits after weekend emergency

Transpower has restored the circuits it took out of action over the weekend, because of concern they could be damaged during the solar storm.

The national electricity system turned several circuits off on Saturday, ahead of a geomagnetic storm hitting.

There were concerns the solar storm would damage satellites and power equipment, so Transpower closed down some electricity transmission circuits as a precaution.

People around the world have been enjoying colourful auroras, caused by material being spat out of a huge spot on the sun.

The stunning, colourful lights, or Aurora Australis, it generated were clearly visible around the country.

Transpower extended the notice on Sunday to early yesterday, when further activity was notified.

It said all affected circuits came back online at 4am yesterday without any problems.

There were no power cuts.

Otago University physics Professor Craig Rodger said that despite the storm reaching G5 - the top of the National Oceanic and Atmospheric Administration (NOAA) SWPC scale for geomagnetic storms - it had only just done so.

It was the largest such solar storm for more than a decade in New Zealand - but not as big as those of 2003 or 2001, and he said we had learned a lot since then.

MetService meteorologist John Law said the -7C experienced in some inland parts of the country at the weekend would also have been “perfect for some astronomy’’.

Sunday night was not as cold although inland parts of Canterbury with areas such as Mt Cook down to -2C and the North Island’s Central Plateau would have been chilliest.

Christchurch residents would have woken up to "a touch of frost" but nowhere near as cold as last Friday which delivered a -6C start to the day.

Cloudier, wetter weather would be on the cards in the next few days, Law said.