Really, solar panels are useful? I read the ratings from time to time, and it seems that the space required and the small output don't justify the expense. And you pretty much need ideal conditions, and it isn't always easy to drape them on your bike over your baggage. But I'd be glad to know I'm wrong. I haven't toured much recently, but I suspect batteries seem like the best bridge between power outlets. It also pays to reduce power consumption as much as possible.