Apr 24, 2008

How large can a hybrid go?

When a public transit operator can afford a hybrid they will add them to their fleet. Is there a limit to size that a hybrid can attain? Apparently not. Below you will find a photo of the worlds largest hybrid.

It's not a bus, but I just wanted to demonstrate that there seems to be no limit on size.

Haul trucks are basically massive dump trucks used in mining operations. They, of course, consume massive amounts of fuel, and so increasing effiency marginally can save massive amounts of fuel. Already, most new haul trucks are electrically powered, like diesel locomotives. Their diesel engines power generators that power the electric motors. This is more efficient than traditional drive trains, and provides much more torque for moving such gigantic loads.


Nick J Boragina said...

Not only do electric engines provide more torque (good for climbing hills I might add) but the hybrid design has another advantage.

Internal Combustion engines cannot be brought to a sudden stop, in fact even when not "in use" they must continue to run, and provide power. Normally, the clutch is applied during these times and that power is wasted, but on a hybrid, that power is stored in the form of electric energy.

When it comes time to hit the gas pedal, an internal combustion engine has to draw 100% of the power for combustion, wile a hybrid might draw 50% of the power from the current combustion, and 50% from the PAST combustion - AKA the power stored in the batteries. Since it is during these 'bursts' of energy that buses (and trucks, etc) can generate the worst of thier emmissions, and use the most gas. Therfore this design is just plain smart.

Add to that the ability to have the wheels generate electricity just by going around (meanwhile slowing the vehicle down - its call dynamic breaking) you end up with a new problem, and that is limits on how much power can be stored in batteries. Hopefully in 10 years we will reach a point where technology will allow us to have a hybrid that can run with it's combustion engine near idle for 90% of the time, while the vehicle uses energy stored in some kind of supercapacitor. This would be great for the environment, as well as fuel efficiency.

Andy said...

Nick... Thanks for the further insight into hybrid technology. It looks like it will be sometime before we see any hybrid buses at DRT.

David Harrison said...

Andy, note that the 26 buses being ordered for the BRT service will be hybrid. Durham Region has already been given the money for these buses, so I would assume an order will be going in soon.

As for when we'll see them in service, if I had to guess, I'd say 2010 or 2011 depending on how quickly they move on the other elements that are required. So far, I haven't seen an "action plan", but one should be coming soon, I'd think.