Orion says power is back on to about half of Christchurch's central business district and 96% of its network in the city.
The lines company says the total number of customers off the entire network is about 10,000 - about half of which are in the CBD and most of the rest are in the Brighton and Dallington areas.
It says it has to work around the operations of the Urban Search and Rescue teams working in the CBD which has slowed down the process of reconnecting power in the area.
Orion says it may have to take power off in some areas of the CBD over the next few days to allow the USR teams to work safely.
Its chief executive, Roger Sutton, says about 5000 customers in the Brighton and Dallington areas are running off big generators.
He says the Royal New Zealand Airforce is providing Orion with the generators which is making a big difference in these areas.
Mr Sutton says if necessary Orion will bring more generators in from Australia.
The lines company is aiming to have power restored to 99% of the city, excluding the CBD, by Monday night.
Orion is urging people to be restrained with their energy consumption.