The new electric double decker unveiled by Bravo Transport’s mainland joint venture Friday has sacrificed up to 22 passenger spots to a gigantic 5-tonne 450kWh battery pack, a design which an international bus technology expert says is unnecessary and wasteful.
Paul Bromley, managing director of Phoenix Consulting, says large and heavy batteries are not the way forward for Hong Kong buses, taking up too much space and reducing range efficiency due to their weight.
According to Bromley’s calculations, the batteries on the new Wisdom (Fujian) bus displace 11 seats and around 11 standing passenger spaces.
Photos obtained from inside the new bus show two huge battery blocks in place of the usual few rows of lower-deck back seats.
These brown-grey cubes are not visible in any of the press photos supplied or the brochure for the Wisdom bus.
“In a competitive market environment electric buses should be able to fulfil the same role as a fossil-fuelled bus,” says Bromley.
He says the heavy duty cycles of Hong Kong buses, including air conditioning demands, mean “simplistic plug-in battery charging is not necessarily the right answer”.
Bromley, who is a pioneer of electric buses and minibuses and led the movement to bring hybrid buses to Hong Kong in 2007, says the benefits of electric buses can only be achieved by adopting “prevailing technologies that are able to deliver as such.”
He has advocated the “opportunity charging” concept, whereby smaller batteries are charged more frequently, instead of the tonnes of batteries seen in the passenger compartment of Hong Kong’s first electric double-decker bus.
But developing “opportunity charging” infrastructure requires coordination between different departments and so-far has only been trialled on a handful of green minibuses, with pantograph charging being trialled at a Kwun Tong public transport interchange.
Bravo’s new bus, developed jointly by Bravo and mainland firm Wisdom (Fujian), was unveiled on 29 April at a high-level closed-door ceremony with guests including Chief Executive Carrie Lam, Transport minister Frank Chan Fan and Environment minister Wong Kam-sing.
The double-decker packs a 450kWh lithium iron phosphate battery, a 125kW motor and can fully charge in around three hours using a 150kW charger.
But Bravo’s backer Templewater is not putting all its bets into the battery concept, with a plan to bring hydrogen-powered buses into Hong Kong “during the next quarter”, it said Friday.
“We believe that hydrogen fuel-cell technology, alongside battery electric are both viable options for Hong Kong’s operating environment,” it said in a statement.
“With both battery electric and hydrogen fuel-cell double-decker buses being tested in parallel, we can partner with the government in formulating a comprehensive plan for our city’s transition to carbon neutral transportation.”
Meanwhile Bravo says it will press the new Wisdom bus into service later this year. The company would not reveal its plans for any specific route or service for the bus.