A lightning strike cut power briefly to about 200 homes around Alexandra and in Clyde on Saturday.
A thunderstorm hit the area about 5pm, and homes in Muttontown between Alexandra and Clyde and in the newer housing subdivision in Clyde had no power for about 20 minutes, Delta's systems control manager for Central Otago, Graeme Johnson said.
Waikerikeri Valley homes were also affected and power was restored there about 6pm.
"The only thing we can put it down to was that it was probably a lightning strike," he said.
The lines had "lightning arrestors" which shorted the lines to earth when lightning struck, so there was no damage to equipment.
He believed an overhead line in the Waikerikeri Valley had probably been hit.
"I was driving through the Cromwell Gorge at the time and couldn't believe the volume of rain bucketing down and there was a huge strike of lightning above the lake [Dunstan]."
The thunderstorm was concentrated on a small area, and orchards missed out on the rain.
