Could be diesel or propane either way wouldn't have been hard to design a box for it to sit in so that the fumes could still go outside.
After an apocalypse like that it's unlikely that solar or wind would be very viable it would most likely be nuclear winter so that would stop both as solar is not going to get any sunlight and a windmill is going to require excessive maintenance to stay functional in that.
The better bet would still be battery bank but battery bank with generator that way you're not just wasting electricity since a generator is a demand-based response but still uses a set amount of fuel no matter what just to run you use the generator to charge up the battery Bank and then use the batteries only turning on the generator when they need to recharge


Yeah as much as I love ublock origin and use it heavily. I support more rust on more things. 60+% of browser CVE are memory issues. Rust was explicitly made to stop those.