Preparing for winter. What do you guys do if the power goes out?

So recently we had a really big wind storm and the power was out for about half the day. With the bad winter last year and the weakened trees, it kind of gave a possible taste of what's to come if we have a bad winter again. What do you guys do to help your tanks if the power goes out? We have never had power outages for more then a day, but places not far from here had power out for 3 days at one point last year. If we have a bad winter again I think the weakened trees may cause us to have the power out longer. I want to be as prepared as possible so that if power does go out for a day or two, I loose as little as possible. Thanks!