What if the sun is hiding for several days in a row?

I hike quite often in the mountains and fortunately so far I have never had a disastrous weather on a full or two weeks. On the other hand, I've already had gray or rainy days on a few nights. What will happen with our solar bikes if you have 3 days in a row where we cannot recharge the battery? In the middle of the Alps, with passes to cross? Well I guess we'll need good thighs and good calves… In order to avoid this eventuality, I chose to swap my crankset for a MTB pedal, with smaller trays, so. But when I tried to mount a SLX crankset, oddly enough I could not make the settings for each tray to pass correctly. So I entrusted my mount to my bicycle mechanic, gables-on-streets, and he found the solution! The problem is that the joysticks are not necessarily adapted to the draw of the MTB pedals. The solution was to use a very old Shimano RSX 100 type controller. The knowledge and know-how of our Yokohama bicycle shops is irreplaceable!