You may want to consider stockpiling rechargeable batteries.
A one or two panel solar cell array and associated electronics may give you the ability of maintaining capability without requiring the usage of limited quantity fossil fuels.
The initial cost is higher, but operational longevity is greater than traditional batteries.
WARNING & DISCLAIMER:
SELECT AND USE OUTDOORS AND SURVIVAL EQUIPMENT, SUPPLIES AND TECHNIQUES AT YOUR OWN RISK. Information posted
on this forum is not reviewed for accuracy and may not be reliable, use at your own risk. Please
review the full WARNING & DISCLAIMER about information on this
site.