Vijay Barve

TRANS-CANADA HIGHWAY — Mile after mile along this stretch of Canada's main highway, the faces of the farmers, truckers and oil workers who turned to look had the same dumbfounded expression, as if asking: What the heck were those? UFOs on wheels? Stealth fighters with their wings clipped? Supersized remote-controlled cars?

No, the contraptions were race cars powered by the sun and the ingenuity of students from 18 universities in the United States and Canada.

The university teams were competing in the North American Solar Challenge for a trophy and the bragging rights to having won the world's longest solar car race.

They weren't salesmen for solar cars. In fact, experts say solar cars won't be viable for many decades to come, if ever. But the cars and last month's race showcase recent advances in technology and demonstrate the promise of solar energy.

Students and experts talk of using solar cells to assist cars, perhaps providing energy to cool off the interior on a hot day while a car is parked. They're even more excited about solar energy for homes and other buildings in regions where there's plenty of sun to go around.