Tim Woodall wrote:

On Sat, 07 Jul 2007 21:20:34 GMT,
Olof Lagerkvist wrote:

wouldn't it be better to build a trolley-bus network with trolley buses
with regenerating brakes?


Regenerative braking depends on being able to guarantee that you can
dump the energy somewhere.


Yes, it is a bit complicated but (and as you say) it can be done. I was
thinking about some regulating combination of rheostatic brakes and
regenerating brakes like the technique used on some tube trains nowadays
(and also some other kind of railway and tram systems in different
places). London Underground claims that they save around 20-25% per cent
of energy on the lines equipped with regenerating braking.

I know however that we are talking about buses and not trains here and
that today most trolley-bus systems with regenerating brakes are
actually regenerating to a battery pack, either always or when wire
connection is lost, but still I think that trolley-buses are more the
right thing for the future than hybrid energy buses with battery packs are.

Super capacitors look promising for the future for regenerative braking
(regardless of what power source is used).


Yes, something like that will probably make the problems around
regulating regenerating brakes at least easier as it seems.

I'm wondering if we might start seeing something like this soon for
bicycles. I think that generator/motor plus supercapacitor ought to come
in at under 2kg[2] with the ability to store enough charge to stop (and
accelerate) a cyclist from 20-30mph to rest.


Funny, I saw a post about this idea in a mountainbike forum just a
couple of days ago. Seems like there are growing expectations on
supercapacitors for this kind of tasks.

--
Olof Lagerkvist
ICQ: 724451
Web: http://here.is/olof