The facility has backup generators, but the blackout slowed passengers trying to check in.
Mindy Hamlin with RDU said Progress Energy was working on a substation when the power went out.
The power outage affected all passenger check-in at Terminal 1 and Terminal 2. There were some delays with arriving planes as the jet bridges operate on electricity.
The air traffic control tower was running on generator power thus planes could still land and takeoff.