Just a (hopefully amusing) piece of anecdata: we have a squaredrop trailer, with a set of solar panels to power/charge the 12v marine battery and a pair of Jackery power banks. Most of our camping is done in the eastern woodlands: WV, PA, VA, etc.
There is so much tree cover all the time. Some days, even though it's mostly or fully sunny, we're almost always at the end of some disused fire road on the wrong side of a mountain, and we're lucky to get a couple of % back from all-day charges. I'm considering one of those water-powered turbines, since it'll work all night long as well.