Experience with off grid solar PV systems:

Steve's Off Grid Vacation Trailer 
with LED lighting powered by PV panel on roof and 12 volt deep cycle battery.

A Friend's High Tech Camper Trailer - in daily use. See link: www.thislittlecamper.com

Solar vented storage shed.

$50 dollar solar fan:
Natural lighting paired with low cost solar ventilation keeps storage shed comfortably cool.

Interior view of underside of solar fan.
A rechargeable battery continues to power fan past hours of prime solar exposure.