Lines company Orion says the number of properties in Canterbury without power will be down to 350 by Thursday night.
The outages follow last week's storm, which caused major damage to power lines throughout the region.
Orion chief executive Rob Jamieson says getting power back to the remaining customers is taking some time, as a repair that can take up most of a work crew's day only brings back electricity for a handful of properties at a time.
Mr Jamieson says residents using generators should make sure they're installed by registered electricians, so workers repairing the network aren't put in danger.
Initially, 28,000 Orion customers were without power.