Tauranga power outage likely caused by a bird's nest

A power cut in Tauranga happened at about 9.45pm on Thursday. Photo / Michael Craig

A power cut that affected 35,000 Tauranga properties was likely caused by a bird's nest.

Power was lost to the Tauranga CBD and several surrounding areas about 9.45pm on Thursday.

On Friday, a Transpower spokesman told the Bay of Plenty Times said its crews found a faulty insulator at a substation which was a piece of equipment that kept electricity from being earthed and "kept everything safe".

"It was on one piece of equipment called a disconnector so that's what we have to isolate ... before we can start to bring people back on."

The main power connection was back by about 12am and the city's remaining customers had power by about 1.20am.

Today, a Transpower spokesman said it had determined the outage was likely caused by "a bird's nest fouling the correct function of an insulator, effectively providing a short circuit".

"Birds are unfortunately an ongoing challenge - our teams regularly monitor our sites and remove nests when they are spotted and we have many bird deterrent systems in place (like anti-nesting spikes).

"But of course, birds will often find a way, particularly in a comparatively warm substation," the spokesman said.

"While we have identified the culprit, we are continuing to investigate aspects of the fault and whether we have ways of minimising the extent of similar outages in the future.

"We are also actively working with Powerco on the future electricity needs out to 2050 in the wider Tauranga area. That work is identifying a number of projects to help ensure a reliable supply to service this fast-growing and important region."

On Friday, a spokesperson from The Warehouse said its Fraser Cove store had no Eftpos in the morning due to the power outage. It was back up and running at about 1.30pm on Friday.