Actually, diesal engine technology has moved a long way over the last 7-8 years that
it has become very efficient and less polluted than a lot of people think. A Euro-3/4
standard diesal is actually emitting less pollutants, with the exception of CO2. They are
so good that Transport of London did not even bother to consider putting gas buses in
service, as they would not bring much more benefit in terms of cost and environment.
I agree that fuel cell bus will be a good idea, but the price is much too expensive now for
what it is, and there is absolutely no provision of infrastructure to support their operation
in HK anyway. Unless the government is actually taking the lead and put in some investment,
there is very little chance you will see a fuel cell bus to appear in HK, in the next 5-10 years
I suspect.
If anything, I see hybrid-powered buses to be the more likely candidate to appear in HK in
short term, esp. London is looking to evaluate a few hybrid double deckers like the Wright
HEV and Volvo's hybrid "B9TL"s this year. If the trial proves successful, I think we stand a
good chance to se the first hybrid double decker in HK in the next 2/3 years.
Apart from the Hydrogen Fuel Cell bus, there is also an hydrogen bus somewhere.
Due to the pressurised nature of CNG, if it is fuelled too quickly, only a limited amount of gas can be taken.
Realistically it needs to be fuelled overnight, and not many bus systems can afford to do so.
For single decks pre-low floor days the gas tanks are mounted under floor. As low floor buses came they
were relocated to the roof. With a double deck there is no room for it on the roof and hence some upper/lower
deck space currently used for seating will have to be sacrificed.
