I would think they would have generator back-up especially since it happened before.
Heck, *two* generators, in case one doesn't start, for that function.
An April 19, 2006, NBC article linked from today's article was about a power outage in the San Diego radar control center. They had backup power, so they were only out for a few seconds. I find it hard to believe there isn't a similar system in Palmdale.
Also, although power usage is high due to weather, demand has not exceeded supply, nor have there been rolling blackouts this year.
As far as I know it's an unmaned facility.
All the personel were moved to Mirimar a few years ago and operate all the equipment remotly.