Shanghai has seen the light - and it is green.

Lights on roads, bridges, tunnels, public transport and governmental buildings will all use environmentally friendly technology in three to five years, officials from the Shanghai Science and Technology Commission told the Shanghai International LED exhibition yesterday.

LED (light-emitting diode) lights have a longer lifetime and can use less than half the energy of traditional bulbs. About 20 percent of the city's electricity is used on lighting.

The development and promotion of LED lighting have been widely embraced by both government and industry.

Shanghai is one of participants in a recent project by the Ministry of Science and Technology to promote LED lights in major cities.

"We have finished a draft on LED adoption and promotion in Shanghai," said Guo Yansheng, director of the Shanghai Science and Technology Commission's high-tech industrialization department.

"The 2010 Shanghai World Expo is an excellent opportunity to showcase LED technologies. All landscaping lights in the Expo zone use LED lighting, while road lamps and exhibition halls will mainly use LEDs."

The exhibition, which will run until Friday at the Shanghai New International Expo Center in the Pudong New Area, also has an LED road-lamp contest. Winners' designs would be used in the Expo zone and introduced to the government for wider use.

Nearly 95 percent of local traffic lights use LED lighting, while the next steps are for road lamps, public transport lighting and government buildings.

Since the price of LED lights is still higher than traditional products, the city government is studying subsidy policies to help promote them in the market and streamline their public use.