I'm only half kidding. I'm a bit of a prepper and I have lots of powerbanks and devices that charge from USB but besides idling my truck I really had no other way to charge any of them in case of a long-term power outage which seemed a bit of an oversight on my part.
Not like this solves the issue. 30 watts (under ideal conditions) isn't much but it's a start.
It will keep you warm for a little while, but not for long.
If things hit the fan, lights can be a cheerful thing to have. But if it's a widespread power outage that lasts, the internet goes down, and cell service follows pretty quickly. Maybe a Game Boy is usable, but your tablet will be a paperweight, and forget the NAS. On the upside, there just won't be much you are going to need electricity to run at that point.