I am planning a trip cross country with a BOB trailer instead of panniers. Since I am not a athlete I plan on adding a Falco motor to the bike for a pedalic assist. This would help me reduce hill grades and head winds. I am planning on charging with solar on the road when I camp and will be using these 240w fold out panels. They are not cheap but can be used to quickly charge batteries http://www.hi-powercycles.com/product.sc?productId=133 these cells have an efficiency rating of over 24%

A 36v 12AH battery would charge in 1:40 mins. I plan to use this power to also charge phones, GPS and so on. Start early in the morning and take a 2 hour lunch break and fully charge the system with the 8 amp solar charger.