Hybrid Buses - How do they work & why are they so heavy?

LordSutch wrote: »

I have read in Buses magazine (December addition) that the New Bus for London weighs 11,800kg which seems tad a excessive to me (as a novice in these issues), so what do you say, is the NB4L excedingly heavy? or would you expect a 'Hybrid' to be heavy in comparrisson to a straight Diesel.

How much does the Dublin Bus WH1 Hybrid weigh?

I know very little about buses. I'd imagine most of that 11.8 tonnes is pure bus. The hybrid components probably don't make up more than 0.2 of that.

To put it into perspective, the diesel engine itself probably weighs around 200 to 250Kg.

In a Prius the battery pack weights only 53Kg.

LordSutch wrote: »

Yes indeed that makes sense, having the extra battery weight would certainly help it pass the tilt tests, (presuming the batteries actually weigh a lot)? that still seems unclear to me! so I still wonder are they responsible for all the extra weight that the New Bus for London carries?
By all accounts she's much heavier than other buses, I think?

You are incorrect. 11.8t is not heavier than other non-hybrid buses of similar size.

What may be confusing you is that it is longer than most previous types in London bus fleets which would be lighter due to their smaller size.

Carawaystick wrote: »

an ignition compression engine uses feic all fuel when under no load. Harvesting the breaking energy would be waaay more productive, ( there's a lot more energy; happens almost as often.)

It uses fuel, and put enough of them together, sitting there not moving, and your air quality is awful.

Cookie_Monster wrote: »

Saw that elsewhere too. I can only presume the trial did not go well enough to bother if it's been withdrawn already.

Like many similar eco-friendly projects worldwide,WH1 was a politically inspired move.

In the short term it enabled a suitable Ministerial Photo-Op and simultaneously scratched Wrights of Ballymena's back with a bit of free publicity.

It also needs to be understood that the WH 1 is based upon a VDL (DAF DB250) underframe and thus sticks out like pinocciho's nose from the other 99.9% of the DB fleet.

In engineering accountancy terms Dublin Bus runs a tight ship and much of the tightness comes from a highly standardized and relatively narrow band fleet.

I would not be surprised if WH1 ended up back in Ballymena for a substantial programme of upgrading to the same standard as their hybrid single decks supplied to TfL.

Whilst there is somewhat of an appetite for Hybrid buses,this is only where Governments are prepared to put cash upfront to assist in the purchase of the vehicles.

One example being the UK,where the Government has just pledged a third tranche of £25 Million of "Green Bus" funding specifically to allow further Hybrid/FuelCell introduction.

Even in the USA,where EPA clean-air regulations have been in place for decades,the Federal Government subsidises their purchase and (in some cases) operation,as many operators have been scathing in realtion to the actual savings vs those promised by manufacturers.

In European terms,Germany,percieved by many as the market-makers in technology terms appear to be cooling off in the attitude to Hybrids with Berlin's BVG being the latest major municipal operator to cancel Hybrid orders on the basis of each bus having an €100,000 premium.

At the moment the Jury appears to be out as to which way the decisions going to go,but current Diesel technology,even with EuroVI regulation immenent,still shades it on cost grounds