Lines company Orion Energy says it will begin the difficult task of disconnecting about 1000 earthquake-damaged buildings in Christchurch's inner-city from mains power on Monday.
Electricity supplies have now been restored to more than 60% of the inner-city and almost all of the outer suburbs since the quake on 22 February.
Orion chief executive Roger Sutton says many damaged buildings are preventing the restoration of power to other customers, but disconnection work will only occur where its safe for crews.
Orion is preparing to build several new overhead power lines in the eastern suburbs of Christchurch to meet demand over winter, he says.
