The setting I'm trying to build is perhaps best described as "Mad Max in Space" - except civilization hasn't collapsed and tanks and airplanes are still a thing.
- Planetary colony established for ca. 250 years
- Mostly cut off from earth (interstellar flight = super rare)
- Thus, colony mostly utilizes resources found on the planet
- There's a big war going on: easily fixable low-tech machines rule
Now I'm wondering how those air and ground vehicles might be powered.
I could just explain that the colony planet once had native life and oceans that provided the environment needed to produce oil, identical to earth, but is that even plausible?
What is the next likely fuel source that could be used in fighting vehicles that are maintainable + fixable by average Joes?
- Nuclear fission is out. Too dangerous when vehicles are damaged.
- Electricity + simple lead acid batteries probably can't hold enough power
- Could natural gas occur without historical extraterrestrial life?
- Hydrogen fuel cells sound okay, pressure explosions could be acceptable
- Whether the planet was terraformed for the colony is still open. It would help if it was /lightly/ terraformed (i.e. habitable temperature range, only some oxygen-producing bacteria were needed)