I’m only half kidding. I’m a bit of a prepper and I have lots of powerbanks and devices that charge from USB but besides idling my truck I really had no other way to charge any of them in case of a long-term power outage which seemed a bit of an oversight on my part.
Not like this solves the issue. 30 watts (under ideal conditions) isn’t much but it’s a start.
Instead of looking at number of panels, look at the total wattage. How many watts does it take to charge your power station? 30W-100W portable solar panels like these should work well for that. You could even go a little higher than what you need because of things like inline charging and dual charging, so you can charge multiple devices at once and still keep the power station topped off. That’s a good starting point.
Next, ask yourself how much wattage you could regularly use it for on a normal day. Ignore high-wattage appliances at first, like refrigerators, a/c, heater, stove, coffee pot, hairdryer, etc. Basically anything that produces high temperatures or has a motor a motor. But what else could you power on it? Chargers, homelab, router, etc.? There’s your second expansion. Probably some larger one-off panels and a couple power stations
Lastly, ask yourself what wattage you would need to run all your necessities in the case of an emergency with a long-term power outage. That’s when you calculate the high-wattage appliances. This will probably require a full rooftop solar installation.
So no need to dive all the way in at first if you can’t afford to yet, but don’t let that discourage you from getting some smaller panels to start.