A 1.20pm update said Powerco had been able to backfeed power to half of its network, while Transpower teams worked to get the remaining power on.
Bay of Plenty Civil Defence said via social media that several hundred homes had lost power in Mount Maunganui and it was also affecting traffic lights, advising people to take care on the roads.
Transpower earlier thanked people for their patience while its crews worked to restore power and investigate the cause of the substation fault.