Hi Cheryl,
A better price for solar panels is Northern Tools (
http://www.northerntool.com/sh...) They have a 2 watt unit on that page for $17.99, and a 7 watt for $37.99. These will run small computer type fans; presuming you don't need to run fans at night you don't need a battery or regulator (which would be to prevent overcharging the battery).
A heavier fan would require a larger panel (or several panels connected together). Northern Tools has a Schumacher brand 12v, 1.8 amp - that's just over 21 watts (12 volts X 1.8 amps); it is 8" in diameter & I believe it oscillates.
RV and camping retailers deal in items for vehicles and trailers that run on 12 volt car batteries. Many of them will carry solar panels, fans, etc, but personally I would look to the online world for much better pricing.
