Solar panels

Start with the location, not the wattage. On the move, weight and folded size matter more than the last few percent of efficiency, so look at portable solar panels with a manageable pack size and the connector your power station uses. For a fixed array the available surface decides: measure the space, check the sunniest side and the shade from trees or chimneys, then pick a panel format that fits. Do not forget the rest of the chain, because a panel on its own does nothing: you need an inverter or a charge controller and mounting hardware suited to your surface. If output is unclear, work backwards from how much you want to charge per day.