Best option for power failure?

[emceeee]

Hello,

I did a search on this but came up short. My electrical utility has scheduled a 10 hour shut off. I'm trying to figure out my best option for a small 50 g tank. I know I could rent a generator, but would rather buy something so I have a back up in place should there ever be a protracted unscheduled failure, when there will be a run on generators.

Generators are very expensive - at least the ones on line at Home Depot. Is there another option - battery-based, perhaps?

I have a pump, a skimmer, a heater and lights. I could do without the skimmer and the lights for 10 hours.

Ideas?

Thank you.