Forget cooking oil. Any good, old school diesel will run on used motor oil or even new motor oil. After the SHTF it'll be a hell of a lot easier finding both of those sources than cooking oil, especially if you're in some small town out in B.F. Egypt.
Transmission fluid will work to. My buddy has a 7.3 liter turbo diesel that runs off used transmission fluid, just be sure to filter the crap out of it.
you can create a human powered generator with a bicycle and a stationary stand.
solar pannels
windmill. i understand they have some amount of maintenance tho. could be an issue.
get a set up that makes sense to charge only what you need. obviously chargin a cell phone makes no sense.
Glad someone else noted the no need for cell phone charging. Why charge a useless item, when the power lines are down, what powers the cell towers..... if they are still standing. Note to file, if your SHTF plan includes calling everyone, call early..