Submitted: Jul 6, 2008 - "Smart Energy Stuff offers a variety of solar-powered golf carts, from $6,000 to $9,000. The costs are on par with those of regular electric-powered golf carts, but they come with the added sweetener of one-time state and federal tax credits of up to $990. "Things are tight," said Njoku, a Nigerian-born New York City transplant who has lived in Fayetteville with his wife for the past three…