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.
Wood is a potentially scarce resource, access to it is situational, it requires significant storage space, wood smoke is bad for you, fire is dangerous and requires skill to manage that can take a long time to learn, same goes for the process of preparing the wood.
Depends a lot on what you are making and how. Haybox cookers require very little fuel. Just get the food up to almost boiling point and that is all the fuel you need.
I looked up haybox cookers, seems like a neat idea to insulate already boiling water, but a wood fire doesn’t seem like the most convenient or efficient choice if what you want is to efficiently heat something up a specific amount but no more.
Just light a small fire and keep it pretty small and it can burn out once you are done.
I use a Kelly kettle stove a lot, tiny fire but still a few thousand watts of thermal energy. A few sticks at a time as fuel.