Power failed at the T2 domestic terminal on Friday morning and has since been fully restored, the airfield operator said in a statement on its website. Thirty four plane arrivals and 36 departures were canceled, according to Australia's biggest airport.
''We expect to clear the backlog as soon as possible,'' said Laura Stevens, a spokeswoman for the airport.
Virgin Australia canceled some domestic flights on Friday because of the outage, as did low-cost carrier Jetstar. The terminal is used by Virgin, Regional Express, Jetstar and Tiger Airways. Qantas, the country's biggest carrier, flies from the T3 terminal.
Sydney airport is the country's largest and had 37.9 million passengers and 169,534 domestic aircraft movements last year, according to its annual report.