The summer quiet on campus was broken when a fleet of bizarre-looking cars made their way into Tsinghua University in Beijing last week.

Looking like a flock of birds, the flat, glamorous cars caused a sensation among the few students still on campus during the summer holidays and even some teachers.

Resting on open ground in front of the university's main building, the three cars - all less than a metre high - were guarded by their proud drivers and talked about by surrounding spectators.

They were solar cars created by students from Tsinghua and two United States institutions.

After a road show and a race along eastern China, they were wrapping up their tour with a final run around the campus amid cheers from the spectators.

The event was the largest of its kind held in China but it was not a pure race. Rather, it was a combination of a race and a show.

Wesley Day, a member of the University of Missouri-Rolla team, said: "It made things quite different from a normal solar-car race. We had to drive under conditions we've never had."

It's showtime

The Missouri solar car, called Solar Miner III, had taken part in races and test runs in the open desert in Australia and the United States, but Day said it had to adapt to China's city avenues and narrow campus roads.

The three teams set out from Shanghai on August 1 and travelled north to Nanjing, capital of East China's Jiangsu Province. They then headed for Tianjin before wrapping up the tour in Beijing on August 15.

However, the three solar cars spent most of the journey of around 2,000 kilometres being carried in the back of a truck.

Road shows were staged in central Nanjing and at the campus of Hebei Industrial University in Tianjin on closed roads, causing a sensation among passers-by.

When the teams arrived in Beijing, a short race was staged at a track on the outskirts of the city. It was the only straightforward competition among the three teams.

Solar Miner III won the not-so-exciting competition, followed by Ra IV of the Illinois-based Principia College and Tsinghua's Sunchase.

Solar Miner III has taken part and excelled in several races over more than 1,000 kilometres, so such a short-distance run was a piece of cake, said Day, an undergraduate majoring in electronic engineering.

But the China tour was by no means an easy journey, the participants said.

Guan Hua, the driver of Sunchase, said things were sometimes harder than expected.

To prepare for the race, the Tsinghua team carried out technical renovations of the car created six years ago in collaboration with Hong Kong University to improve its efficiency.

But the Tsinghua students found it still took time to adapt the car to road conditions, as did the other student teams.

Driving on city roads lined with curious onlookers is not as leisurely as driving under normal conditions, Guan said.

There were no guiding cars or technical support teams, which are common in more formal solar-car races.

What remained unchanged was the consideration of weather conditions, as the cars' major source of power is sunlight, supplemented by batteries.

Many tactical choices have to be made according to changes in the weather in order to win, Guan said.

The basic tactic was to follow the clouds, he said. "We must make sure we drive in sunlight for as long as possible," he added. "You have to consider whether or not there are clouds and change speed when necessary."

All three cars were equipped with batteries in case there was no sunlight. Solar Miner III, for instance, can travel for 300 kilometres on its battery alone, the longest distance among the three.

Craftsmanship matters

All three cars performed steadily on their journey, despite a few minor breakdowns.

Their average speed ranged from 50 to 80 kilometres per hour, depending on their weight and dynamics, as well as their craftsmanship.

With no industrial standards or assembly lines, the manufacture of solar cars is still largely a handicraft that can be done in the backyard.

The making of Ra IV by the Principia College students was a case in point.

Most of the 19 students on the team had no technological background, but they managed to create the car that came fourth among 12 entrants in the Formula Sun Grand Prix in May this year in the US and seventh among 30 entrants in last year's American Solar Challenge.

The members of all three teams looked for funds, did the designs and bought the car components by themselves.

Solar Miner III, which is much lighter and quicker than Ra IV, cost a little more than US$100,000, about US$50,000 less than Ra IV.

The fact that most of the Missouri team members study engineering and mechanics helped a lot in making the car cost-efficient, Day said.

But when it comes to the future of solar cars, Day appears less sure than about the quality of his team's car.

Many issues remain to be tackled, he said. The solar car still relies heavily, if not exclusively, on sunlight as its source of fuel.

The surface area of the car that absorbs sunlight is prone to malfunction and driving remains far from comfortable, added Day.

Guan Hua, from the Tsinghua team, appeared more optimistic, placing his hope on future scientific advances in this field.

"Few could have imagined 10 years ago of solar cars with a quality and speed like those of today," he said. "So who can imagine the next 10 years?"

(China Daily HE SHENG 08/23/2002 )