"Electric golf cart that has an array of 72 photovoltaic cells built into the roof that collect solar energy, providing up to 33% more range between recharges than non-solar electric golf carts. The carts 160-watt array produces up to three amps per hour for its 48-volt rechargeable battery system, providing a range of up to 49 miles"
http://www.hammacher.com/publish/11164.asp?promo=homepage_hero#But even better is and a lot cheaper is the 14 M.P.H. Cooler
"This is the only ridable, three-wheeled cooler with a 500-watt electric motor that propels the unit up to 14 mph, and it has a fully insulated bin that accommodates up to 24 12-oz. beverage cans and 8 lbs. of ice, allowing you to transport chilled food or beverages up to 15 miles on a single charge. The enclosed frame is built from durable yet lightweight aircraft aluminum, and the unit has a chain drive, disc brake, and variable-throttle control, ensuring speeds and handling that are similar to a golf cart's maneuverability. A cup holder is located between the driver's knees, and it opens to allow access to beverages stored in the cooler while driving."
http://www.hammacher.com/publish/74747.asp