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 Monday, when further activity was notified.

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

There are no power cuts.

Otago University physics Professor Craig Rodger tells RNZ 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 says they have learned a lot since then.

-RNZ.