Short power outage

Not bad at all. Autoflowers accept all kinds of light cycles. Everything from 12/12 to 24/0. There are some guides online what cycles to use with pros and cons, but overall you won't have any problems. I, for example, use 18/6, since it's a nice middle ground, so my ladies get enough light (more light=more photosynthesis=more groth), but also my electricity bill doesn't go through the roof. They won't feel the outage of 3h at all, since they're autos. If they were photos, that would be a whole different story... Hope this helps. Cheers 💪