Last year (which was my first) I had solar chargers for AA/AAA/etc batteries (I did not pay $40 for it oi vey) and USB. Being sane people we also had a decent supply of normal batteries and would use those when we ran out of sun-charged bits. The USB was pretty much just for cell phones and sex toys.
Going to need more power this year. Probably going to go with the harbor freight kit that people keep referring to. Haven't decided on battery / charge controllers yet. If you want a nice packaged system I haven't found prettier than these cats.