Water Supply for SHTF Event
If it should all go pear shaped, the number one thing you need is a water supply. Preppers will be well versed on all this - except maybe the Brumby solution.
If you have a well or bore, a Brumby Pump could save you. As it runs on compressed air only, it is extremely versatile. The most reliable way to operate a compressor for the Brumby Pump when the chips are down is diesel or petrol. That's not a long term solution though.
You can probably come up with other ways to run a compressor, but if there is a bit of sunshine occasionally, a DC motor driven compressor is a great way to operate - even after a potential solar flare or EMP attack. It can run directly off solar panels. There are no electronics.
Check the video below for more details.