SHANGHAI, Sept. 6 -- A CONCEPT bike driven by an environmentally clean hydrogen fuel cell was unveiled at an international fair in Shanghai yesterday, with the local producer promising to extend its patented technologies to more pollution-free products.

Shanghai Pearl Hydrogen Power Source Technology Co showed its fuel-cell bike at the 9th China International Exhibition on Gas Technology, Equipment and Applications which kicked off yesterday at Shanghaimart.

The company officials said the model had just been completed late last month and they had already received some inquiries and trial orders from interested buyers overseas.

"Most of the buyers at present are individuals keen on clean energy applications," said Tian Binglun, the company's general manager.

"The innovative bike also attracted the attention of many visitors to the fair today," Tian said.

A battery tank and a pair of hydrogen gas bottles make up the energy system for the bike, making it different in appearance from other electric bikes widely used in Shanghai.

"As is widely known, hydrogen has become a major source of clean energy, together with wind and solar power. With hydrogen gas, the battery produces power to drive the bike without producing harmful fumes but only a bit of water," Tian explained.

The hydrogen bike also has some other advantages over normal electric bikes.

It only takes about 30 minutes to refill the gas bottles. However, it takes at least three hours to recharge the lead battery in common electric bikes, he said.

The energy system, including the battery tank and gas bottles, is also only about half the weight of the battery on normal electric bikes.

"We could also make the battery system lighter by using different materials to make the tank."

The bike costs about 20,000 yuan (US$2,632), but that could be reduced to about 4,000 yuan after mass production, making the price more comparable with electric bikes.

With two full gas bottles, the bike could be expected to complete a trip of 100 kilometers at a speed of 25 kilometers an hour.

The producer said the company expects interested partners to use its core patented technologies on more vehicles, such as motorbikes and golf carts.

But future owners of the bike have to order the gas refills from local suppliers.

"Hydrogen gas is not supplied through a network, unlike gasoline, but we could provide a list of designated gas suppliers in future," said Tian.