I toured with a GoalZero Nomad 7 and Guide 10 combo a couple years ago. Unless you can position it angled directly at the sun and it can sit there all day I found it to be pretty much useless for touring. I tried strapping it onto my bob trailer and the thing just wasn't able to store anywhere near enough power. The mAh capacity on 4 AA batteries is too low to really charge much either.

I've since moved on to using a Lithium Ion battery back (7000mah. I just charge it every few days when I have an opportunity. It's lighter and has a much higher capacity than 4 AA in the Guide 10.