I'm totally nuts about my power and I have over killed it for touring because I want comfort and to charge my gear even on cloudy days.

I had custom built aluminum 'Solar Cage' that fits on my front rack that holds my 300 watt fold out solar panel.

This charges a 52v 15 AH battery (775 usable Watts). That battery connects to a DC to DC converter that takes the voltage down to 12 volts that then connects to a cigarette style lighter. I can connect anything from my inverter to run my laptop and also have a 12v adapter to charge 6 USB devices at the same time. When I need to charge I toss out the panels at lunch time and get a good charge.

I liked the 12 volt system because almost all gas stations will have 12v USB gear. Since my battery is a LINMC it only weighs 7.7 lbs. but the panels and solar cage are 20 lbs.

I don't mind the extra weight for the extra comfort.