Farnan said they waited as long as they could but with limited emergency lighting, they had to call the show off for health and safety reasons after an hour-and-a-half or so of waiting - which included some acoustic crowd singalongs.
"The power came back on about 20 minutes later," he said.
The gig has since been rescheduled for August 4 - same venue, same time.
Any ticket-holders not able to attend would be able to get a refund through the ticketing agent DASH, he said.
The Automatic 80s Live show promised an authentic 80s music experience featuring the "very best of early to mid-Eighties New Romantic and New Wave hits".
The group covers hits from performers such as Human League, Simple Minds, Duran Duran, Blondie, Culture Club, Kate Bush, Robert Palmer.
Performers include front man Justin Maclaren, backed by Pearl Runga (sister of Boh and Bic), drummer Jamie Lee, lead guitarist Danny McCrum (The Buskers) and bassist Clint Harris (Opshop/The Feelers).
