In message om, at
10:55:06 on Tue, 20 Dec 2011, "dennis@home"
remarked:
Of course the greeney in me has to point out that the diesel engine
is clearly incapable of moving the bus on its own which implies it
must be smaller and use less diesel than a conventional diesel bus,
so it is in fact green.

There is insufficient data to draw that conclusion.
A normal bus will drive using lots of diesel then stop using little
diesel, repeat.
The "green" bus will drive using battery and run generator using medium
amount of diesel.

Unless you know what the stop start ratio is and how much it runs the
generator you can't know its green.

It the prius problem, you can run a fully charged prius for a few miles
and claim its green, if you run the same prius for a hundred miles it
uses more fuel than a medium diesel car and it isn't green at all.

You could look at the overall mpg. Which is claimed to be 11.6mpg
compared to 8.6mpg for earlier designs of hybrid bus and 5.8mpg for a
normal diesel bus.
--
Roland Perry