Trial runs of electric buses will be accelerated in the coming years as about one-third of Hong Kong's franchised bus fleet will be phased out by 2015.

Edward Yau Tang-wah, secretary for the environment, said on Thursday Hong Kong should seize this opportunity to push forward the operation of electric buses and promote their deployment in the long run.

An electric bus costs much less than a bus fueled by diesel or petroleum, the price of which has been soaring amid a worldwide shortage, while, on the other hand, its use would very much improve the environment.

The government has come under pressure from local environmental groups to reduce worsening air pollution. Yau pointed out that, in heavily-populated areas like Mong Kok and Causeway Bay, more than 40 percent of the air pollution comes from buses.

According to Eric Cheng Ka-wai, a professor at the Department of Electrical Engineering of Polytechnic University, electric-charging fees are 70 percent less than those of petroleum replenishing costs. Besides, electric buses have proved to be more efficient than conventional buses, with 90 percent of the energy used, while conventional vehicles use only some 20 percent.

Chief Executive Donald Tsang Yam-kuen said in his recent Policy Address that HK$180 million would be spent on acquiring 36 electric buses for four franchised bus companies, including Kowloon Motor Bus.

All the electric buses are single-decker vehicles, while most of the city's buses are double-deckers.

While the deployment of electric buses requires such supporting facilities as special chargers on the routes, the government is leaving it to the franchised bus companies to invest in research and development and the facilities required.

A fast-charger, for instance, may cost between HK$100,000 and HK$300,000, Cheng said.

Cheng also cited the problems that may arise when electric buses take passengers. If there is a traffic jam, these buses could use up more energy than usual.

In summer, when air-conditioning could use up to 40 percent of the electricity, it could lead to the buses being overheated.

Although solar energy can be considered as a substitute, its cost would be much higher than that of electricity.

Nevertheless, Cheng agreed that the government should speed up the promotion and adoption of electric vehicles as oil reserves dwindle.

andrea@chinadailyhk.com

China Daily

(HK Edition 10/28/2011 page1)