A cafe, hairdresser and fish and chip shop remained closed while work went on outside.
Superior Automotive Services, situated across the road, also opened.
Owner Tracey Donovan said closing down for the day was not an option so she had split the cost of a generator with TyreMaster next door.
"We've had to supply our own [generator]. We're not happy at all," she said.
She had called Powerco to questions why the work could not be carried out at the weekend or in the afternoon when it would not affect businesses so much but was never given an answer.
Powerco acting network operations manager Dean Stevenson said the planned power cut affected about 70 customers, the majority of which were residential properties.
"Powerco selected the time for the outage based on the time when demand on the network was at a minimum and create the least inconvenience to customers," he said.
"We've got to balance the needs of 68 households versus three to four shops. It's a tough one for us."
Mr Stevenson said Powerco had been in touch with "at least one" business owner and offered to help him get a generator with a significant discount.
Powerco
• Powerco is New Zealand's largest electricity and second largest gas distributor in terms of network length - electricity 30,000km and gas 6170km.
• The company's gas and electricity networks provide a service to more than 420,000 customers.
- powerco.co.nz