Green hybrid minibuses go on trial this month

The vehicles use new technology that reduces harmful gases and consumes less oil

PUBLISHED : Tuesday, 01 October, 2013, 12:00am
UPDATED : Tuesday, 01 October, 2013, 4:24am

Twelve hybrid minibuses powered principally by rechargable electric batteries will undergo trials on city streets from this month, with a view to the hybrid model replacing the fleet plying green-minibus routes.

The local firm which has developed the hybrids says they consume a third less oil and produce 70 per cent less greenhouse gas emissions than the LPG-powered and diesel minibuses currently in use. The hybrids are also ideal for the city's congested roads, on which vehicles frequently stop and start, it says.

"The battery will recharge when it runs low or when the vehicle is stopped," said Lo Chee-pui, director of Green Mobility Innovations (GMI).

The technology, called regenerative braking, replaces the bus' diesel engine with a dual dynamo comprising a battery and a small diesel engine that recharges the battery - which can last 15 years - whenever it runs out.

Three big operators of green-topped minibuses are taking part in the trial, which will start in the middle of this month. The routes are in Southern District and Tuen Mun, and between Tsim Sha Tsui and Whampoa. Between them, the three firms run 4,350 minibuses. Replacing all of them with hybrids would cut annual greenhouse gas emissions by 160,000 tonnes, GMI said.

Lo said a fully charged battery would last 450 kilometres at 80km/h, after which the diesel engine would kick in. That would make the hybrid no different in operation from a conventional minibus, which clocked about 300 kilometres a day, he said.

Chan Man-chun, of AMS Public Transport, which bought eight of the hybrids, said the government's green transport fund paid HK$900,000 for each of the HK$1.33 million hybrids. A diesel version costs about HK$600,000.

"The industry has long been looking for such environment-friendly minibuses but … the latest Euro V model simply does not fit our operations," he said.

Euro V minibuses have a filter which, under continuous running, automatically cleans out carbon monoxide. It is unsuitable for Hong Kong minibuses, which stop a lot, so the engines won't generate enough heat to burn out accumulated particles, which could lead to breakdowns.