Backup power - what you got?

[604reefer]

First year reefing and after a few of the natural disasters down south I got to wondering what might happen if I lose power. I've never really cared if I lost power until now... it would crush me to lose my fish and coral to an outage.

There seems to be no real consensus online so I'm interested to hear what others here are doing!

1. What do you use for backup power?
2. What equipment is plugged in to it?
3. Tank size?
4. Any other general prep?