Now for a solar array. This is the best deal I could find offhand in terms of wattage for the price:
http://www.amazon.com/Instapark%C2%AE-Mercury27-Portable-Automotive-Batteries/dp/B00EVFEBKU/ref=sr_1_fkmr0_1?ie=UTF8&qid=1404111108&sr=8-1-fkmr0&keywords=wagan+folding+30+wattIt says 27 watts for $110. My 30 watt folding array was around $320. Anyway this is ample for your purposes, but you always want to overbuy when it comes to solar. You gotta account for cloud cover, not being able to sit there angling the panel to the sun constantly and so on. This thing appears to have built in USB ports so, paired with the enclosure I linked you to plus the right cable, you should be set.
