Solar — hand-cranks are a PITA. If you’re in a bunker with nothing else to do then a handcrank may be the highlight of your day. OTOH if you’re in the field, a solar panel can be attached to your pack to charge batteries & power-banks as you walk, or layed in the sun charging while you collect firewood, set up camp, or otherwise do things that would interfere with handcrank duties.
$.02, YMMV