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1337Delta764
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Are Diesel-electric Hybrid Buses Worth It?

Mon Jan 28, 2008 11:48 pm

With ABQ RIDE of Albuquerque, New Mexico introducing 58 New Flyer DE40LFR diesel-electric hybrid buses, this is a huge advance for ABQ RIDE. While ABQ RIDE has operated hybrid buses since 2004 on Rapid Ride, they only represented a small fraction of ABQ RIDE's fleet.

So, does anyone have an opinion on hybrid buses? I know that they are more expensive to purchase than regular diesel or CNG buses, however, I personally believe that they cost lest to operate in the long term. The main problem with CNG is that fuel economy is generally poor even compared to regular diesel buses. With ULSD now available, it somewhat renders CNG obsolete for most transit authorities, as ULSD can burn as clean (if not cleaner) than CNG. Combined with a hybrid system, it results in ultra-low emissions and superior fuel economy.

In addition to ABQ RIDE's order, there are several other transit authorities who are ordering hybrid buses from New Flyer, Gillig, and Orion. New Flyer and Gillig's hybrid buses use a GM-Allison parallel hybrid system, while Orion uses a BAE series hybrid system.
 
desertjets
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RE: Are Diesel-electric Hybrid Buses Worth It?

Mon Jan 28, 2008 11:58 pm

I rode on a few of them in NYC a couple of weeks back. Definitely a different beast than the old RTS buses running around in MTA colors.

Quoting 1337Delta764 (Thread starter):
So, does anyone have an opinion on hybrid buses? I know that they are more expensive to purchase than regular diesel or CNG buses, however, I personally believe that they cost lest to operate in the long term. The main problem with CNG is that fuel economy is generally poor even compared to regular diesel buses. With ULSD now available, it somewhat renders CNG obsolete for most transit authorities, as ULSD can burn as clean (if not cleaner) than CNG. Combined with a hybrid system, it results in ultra-low emissions and superior fuel economy.

In congested urban areas the decrease in emissions vs. older tech diesels/CNG is probably the biggest advantage. No clue about the fuel consumption differences though.
 
ltbewr
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RE: Are Diesel-electric Hybrid Buses Worth It?

Mon Jan 28, 2008 11:58 pm

I believe that NY City has operated a number of diesel-electric hybrid busses for several years. I believe they have constant speed diesel engines, operating at their peak efficiency and with well designed exhaust particularities traps and run via batteries electric motors. I believe that such systems mean moderate fuel costs, using a relatively cheap and easy to dispense diesel fuel, possibly even convertible to LNG or CNG, less need for complicated automatic transmissions and still give the performance in all weather conditions.
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 12:17 am



Quoting DesertJets (Reply 1):
I rode on a few of them in NYC a couple of weeks back. Definitely a different beast than the old RTS buses running around in MTA colors.

Yes, NYC operates several Orion VII HEV (hybrid electric vehicle) buses, and they have several orders for the new Orion VII NG (next generation) HEV. The Orion VII HEV introduces a new body style, similar to that of New Flyer's latest buses.

http://upload.wikimedia.org/wikipedia/commons/8/83/MTA_Bus_Orion_7_Next_Generation_hybrid.jpg
 
Klaus
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 12:21 am

Buses running in city traffic are the perfect example of the kind of stop-and-go operation which should profit the most from hybrid drive - provided they can use regenerative braking effectively instead of constantly and uselessly turning motion into heat with conventional brakes.

Using high-efficiency diesel motors as the primary energy source (possibly augmented by landline charging of the batteries in the depot) would of course make sense, but the hybrid technology could make a significant contribution.
 
scrubbsywg
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 12:22 am

funny, i just saw an ABQ liveried bus today. I work across the street from new flyer's product development offices.

I always thought busses would be the best use of hybrid tech with all the stopping. Does anyone know the fuel consumption numbers? Is it like great savings, or is it just marginal.
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 12:24 am



Quoting Klaus (Reply 4):
Buses running in city traffic are the perfect example of the kind of stop-and-go operation which should profit the most from hybrid drive - provided they can use regenerative braking effectively instead of constantly and uselessly turning motion into heat with conventional brakes.

This is where the BAE series hybrid system that Orion offers excels. The GM Allison parallel hybrid system offered by New Flyer and Gillig generally performs better on routes making less frequent stops, such as commuter/express routes, BRT, or routes that involve more highway driving.
 
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 1:08 am



Quoting ScrubbsYWG (Reply 5):
funny, i just saw an ABQ liveried bus today. I work across the street from new flyer's product development offices.

I know the bus shells are made at New Flyer's Winnipeg factory. I didn't know they are painted prior to delivery. Final assembly, however, is done at New Flyer's Crookston and St. Cloud factories. I know the Rapid Ride buses were assembled in Crookston; I don't know where the new DE40LFR buses are being done.
 
Queso
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 1:49 am



Quoting Klaus (Reply 4):
Buses running in city traffic are the perfect example of the kind of stop-and-go operation which should profit the most from hybrid drive - provided they can use regenerative braking effectively instead of constantly and uselessly turning motion into heat with conventional brakes.

The problem though is having to accelerate that extra weight of the batteries and the hybrid drive, thereby wasting even more fuel that would not be needed if the weight wasn't there.

Then there's the energy used in the manufacture of the extra parts and the toxicity of the batteries, etc. False environmental economy.
 
Klaus
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:04 am



Quoting Queso (Reply 8):
The problem though is having to accelerate that extra weight of the batteries and the hybrid drive, thereby wasting even more fuel that would not be needed if the weight wasn't there.

When enough of that acceleration is recovered by regenerative braking, that effect can be matched and anything beyond that is a pure win.

A conventional vehicle turns all of the acceleration energy into useless heat as soon as it is braked. An efficient hybrid drive can recover a significant part of the initial acceleration energy if the distances between starts and stops are short enough.

Quoting Queso (Reply 8):
Then there's the energy used in the manufacture of the extra parts and the toxicity of the batteries, etc. False environmental economy.

Such a summary statement cannot be made. The question is how large the effects on either side actually are. If the savings are big enough, they can justify a properly manufactured and maintained hybrid drive.

Long-distance highway driving at near-constant speeds is pretty much the worst case possible for hybrid efficiency - it will come out worse than a halfway efficient conventional motor. Your Greyhound buses would certainly not make good hybrids.

But it's a very different thing with municipal buses - they are pretty close to the optimal scenario for hybrid propulsion, so there should be a pretty large potential for increased efficiency there.

For private cars the calculation is similar.
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:06 am



Quoting Queso (Reply 8):
The problem though is having to accelerate that extra weight of the batteries and the hybrid drive, thereby wasting even more fuel that would not be needed if the weight wasn't there.

Then there's the energy used in the manufacture of the extra parts and the toxicity of the batteries, etc. False environmental economy.

New Flyer has actually introduced a low-profile roof cap for the batteries, resulting in less weight than the previous version. I don't think that the weight of the batteries has been much of an issue for ABQ RIDE, as all of their New Flyer hybrids perform fairly well.

The batteries that are used are NiMH batteries, which are less hazardous to the environment than NiCad or lead-acid batteries. Eventually, we may see hybrid vehicles using lithium ion batteries.

BTW, the New Flyer DE40LFR buses that are being delivered to ABQ RIDE will be used to replace old TMC RTS buses from 1989. In addition to being old and more polluting, the old TMC RTS buses lack wheelchair lifts, which is in violation of the ADA. Many transit authorities have reached the 100% wheelchair accessible mark in the mid to late 1990s, either by new delieveries or by retrofitting old buses with lifts. Its a shame that ABQ RIDE never managed to add lifts to the old TMC RTS buses. Because they are now approacing 19 years in age, it is no longer worth the investment, and is better to replace them with brand new hybrid buses from New Flyer.

For those interested, here is what ABQ RIDE's fleet consists of:
  • 101-100 - 40-foot TMC RTS (1989) - being retired
  • 201-248 - 35-foot TMC RTS (1989) - being retired
  • 301-340 - 40-foot Neoplan AN440 CNG (1996)
  • 401-435 - 32-foot Thomas/Dennis SLF200 CNG (2001)
  • 436 - 36-foot Thomas/Dennis SLF200 Diesel (2001)
  • 6401-6412 - 60-foot articulated New Flyer DE60LF diesel-electric hybrid (2004)
  • 6601-6606 - 60-foot articulated New Flyer DE60LF diesel-electric hybrid (2007)
  • 701-758 - 40-foot New Flyer DE40LFR diesel-electric hybrid (2007/2008) - not all have been delievered yet
 
Klaus
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:10 am



Quoting 1337Delta764 (Reply 10):
For those interested, here is what ABQ RIDE's fleet consists of:

Are the hybrid efficiency calculations vs. "simple" modern diesels publicized and how far do the experiences in practice match them?
 
mt99
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:14 am



Quoting 1337Delta764 (Reply 10):
The batteries that are used are NiMH batteries, which are less hazardous to the environment than NiCad or lead-acid batteries. Eventually, we may see hybrid vehicles using lithium ion batteries.

Thats all fine and dandy - but - where is the power coming from that allows you to charge the buses? From coal plants - which in turn have their own environmental footprint. Care from the environment is a concerted effort of many many things not just a few buses running round
 
threeifbyair
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:17 am

King County Metro (Seattle) has the largest hybrid fleet in the US, all DE60LF units from New Flyer. When they were introduced, the Department of Energy's National Renewable Energy Laboratory compared their perfomance with some D60LFs that Metro had also recently acquired.

Here is the report:

http://www.nrel.gov/vehiclesandfuels/fleettest/pdfs/40585.pdf
 
Queso
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:23 am



Quoting Mt99 (Reply 12):
Thats all fine and dandy - but - where is the power coming from that allows you to charge the buses? From coal plants - which in turn have their own environmental footprint.

I think you need to review the basics of how hybrids work. You don't plug it in and charge it up, they recharge the batteries by using the drag of an electrical generator in combination with the brakes to slow a vehicle.
 
mt99
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:31 am



Quoting Queso (Reply 14):

I think you need to review the basics of how hybrids work. You don't plug it in and charge it up, they recharge the batteries by using the drag of an electrical generator in combination with the brakes to slow a vehicle.

While there are new "plug-in" type electrical vehicles (such as the Chevy Volt (http://www.autobloggreen.com/2007/01/07/detroit-auto-show-its-here-gms-plug-in-hybrid-is-the-chevy-v/) are making their way closer to production - You are correct.. i should have been paying more attention to what i was writing.
 
hoons90
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:46 am

Gotta love the sound that the Orion VII NG Hybrids make!

http://ca.youtube.com/watch?v=kd-EQIjcOrw
http://ca.youtube.com/watch?v=f34Ow5P-6RA

[Edited 2008-01-28 18:49:59]
 
scrubbsywg
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 2:49 am



Quoting 1337Delta764 (Reply 7):
I know the bus shells are made at New Flyer's Winnipeg factory. I didn't know they are painted prior to delivery. Final assembly, however, is done at New Flyer's Crookston and St. Cloud factories. I know the Rapid Ride buses were assembled in Crookston; I don't know where the new DE40LFR buses are being done.

That is probably how it works, but they basically have two facilities in winnipeg. They have a full blown manufacturing facility, and they have their product development department(where they design and test new models and parts) which is in the same complex as a service area. I work across the street from the latter one, so we often see buses with liveries from all over north america driving around our industrial park doing testing and what not. Normally, i don't think they paint the buses here in winnipeg as you said. I have an engineer friend that works at the manufacturing plant that i should be seeing this week sometime, so i will ask him how it works.

It just so happened that i saw a bus with ABQ written on it, and then i saw this thread. small world.
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 3:00 am



Quoting ScrubbsYWG (Reply 17):
It just so happened that i saw a bus with ABQ written on it, and then i saw this thread. small world.

Did it look anything like this?:

 
comorin
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 3:09 am

I know what a Hybrid is, and I know what a Diesel-Electric locomotive is - so do these systems use a constant speed diesel engine to generate electric power to run series-wound traction motors? I'd be really surprised if regenerative braking supplied 100% of the electric power.

Thanks.
 
scrubbsywg
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 3:17 am



Quoting 1337Delta764 (Reply 18):

Did it look anything like this?:

I don't think it had the maroon painting on it, but it definately had the "ABQ RIDE" on it. As far as if that was the model, you are asking the wrong guy. Maybe i will take my camera to work tomorrow and take a pic of it.
 
57AZ
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 3:42 am



Quoting 1337Delta764 (Thread starter):
With ULSD now available, it somewhat renders CNG obsolete for most transit authorities, as ULSD can burn as clean (if not cleaner) than CNG. Combined with a hybrid system, it results in ultra-low emissions and superior fuel economy.

ULSD does pretty much beat CNG on two fronts-lower emissions and no need for special fuel islands. Only way to really beat ULSD is to go all electric. Forget the hybrid crap-use the century old, proven technology of the trolley bus.
 
Klaus
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 11:29 am



Quoting Comorin (Reply 19):
I'd be really surprised if regenerative braking supplied 100% of the electric power.

Of course not - that would (normally) be impossible. But a significant increase in efficiency should be feasible, dependent on the traffic profile.
 
Queso
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 1:03 pm



Quoting Mt99 (Reply 15):
i should have been paying more attention to what i was writing

No problem! Just wanted to make sure we were all on the same page!  wave 
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 3:13 pm

For those interested, here is a page on New Flyer's website about their diesel-electric hybrid buses:

http://www.newflyer.com/index/hybrid_buses_intro
 
Dougloid
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 3:23 pm



Quoting Klaus (Reply 9):
When enough of that acceleration is recovered by regenerative braking, that effect can be matched and anything beyond that is a pure win.

A conventional vehicle turns all of the acceleration energy into useless heat as soon as it is braked. An efficient hybrid drive can recover a significant part of the initial acceleration energy if the distances between starts and stops are short enough.

Correct. It's all about BTUs, folks. You gotta spend BTUs to move things around, and how efficiently you do that determines how much fuel you use.

Quoting 1337Delta764 (Reply 10):
The batteries that are used are NiMH batteries, which are less hazardous to the environment than NiCad or lead-acid batteries. Eventually, we may see hybrid vehicles using lithium ion batteries.

I don't know about hazardous to the environment but having worked with lead acid and NiCad batterise in the aircraft trade, they're hazardous to the people who handle them.
 
57AZ
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 5:15 pm

Again, no form of hybrid or battery powered coach beats the efficiency, cleanliness and durability of a trolley bus. They do carry batteries for use when diverting around traffic crashes, but the batteries are used very rarely-thus requiring less handling by staff.
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 5:27 pm



Quoting 57AZ (Reply 26):
Again, no form of hybrid or battery powered coach beats the efficiency, cleanliness and durability of a trolley bus. They do carry batteries for use when diverting around traffic crashes, but the batteries are used very rarely-thus requiring less handling by staff.

Yet again, trolleybuses are limited as that they require overhead lines to run. Those overhead lines use energy from coal or oil burning power plants. Hybrid buses can at least go anywhere.

ABQ RIDE is actually proposing a modern streetcar along Central Ave, however, it has come under fire for poor planning and costs, and thus is currently on hold. A streetcar generally presents an image of a better transit system than any type of bus (including trolleybuses), yet is not as expensive as a full-blown light rail system.
 
LASoctoberB6
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 6:11 pm

Could someone list all types of fuel methods that transit agencies have and are looking to use? Thx

Quoting 1337Delta764 (Reply 3):
Yes, NYC operates several Orion VII HEV (hybrid electric vehicle) buses, and they have several orders for the new Orion VII NG (next generation) HEV. The Orion VII HEV introduces a new body style, similar to that of New Flyer's latest buses.

It has just occured to me, that the new Orion VII HEVs are trying to look like the LFRs...
 
Queso
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 6:13 pm



Quoting 57AZ (Reply 26):
the batteries are used very rarely-thus requiring less handling by staff.

And thus wasting extra energy transporting them around all of the time.
 
LASoctoberB6
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 6:38 pm



Quoting Queso (Reply 29):
And thus wasting extra energy transporting them around all of the time.

And increasing the weight....
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 8:00 pm



Quoting LASOctoberB6 (Reply 28):
Could someone list all types of fuel methods that transit agencies have and are looking to use? Thx

The three most common are diesel, diesel-electric, and compressed natural gas (CNG). However, New Flyer also produces a line of buses powered by liquefied natural gas (LNG). For some transit authorities in southern California, due to very strict emissions laws on diesel engines (regardless of being hybrids or not), New Flyer and North American Bus Industries (NABI) also produce gasoline-electric hybrid buses. BC Transit in British Columbia, Canada has ordered several hydrogen fuel cell buses from New Flyer. NYCT has also once tested methanol-powered buses, however, most have been either converted to diesel or have been scrapped.
 
57AZ
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 8:01 pm



Quoting 1337Delta764 (Reply 27):
Yet again, trolleybuses are limited as that they require overhead lines to run.

Not correct. They can run on storage power if required.

Quoting Queso (Reply 29):
And thus wasting extra energy transporting them around all of the time.

True, but limited. Their additional energy efficiency tends to offset the weight penalty.

[And increasing the weight....[/quote]

With modern battery technology, weight is not a significant issue. Again, the efficiency of the electric motors offsets the weight/energy penalties. When the bus is standing, it is not consuming much energy-just enough to power the lighting.

Quoting 1337Delta764 (Reply 27):
ABQ RIDE is actually proposing a modern streetcar along Central Ave, however, it has come under fire for poor planning and costs, and thus is currently on hold.

Who is the consultant? Tucson is extending it's heritage trolley line as we type-new trackage is being laid along Congress Street right now. Tucson also approved a new Modern Streetcar which is in the end design stages and will be presented to FTA for funding soon. Cars could be rolling as soon as 2012.
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 8:50 pm



Quoting LASOctoberB6 (Reply 28):
It has just occured to me, that the new Orion VII HEVs are trying to look like the LFRs...

Also, Gillig offers the Advantage BRT, even though they still offer the standard Gillig Advantage.

http://upload.wikimedia.org/wikipedia/commons/b/b1/CDTA_Gillig_Hybrid.jpg

I also believe that New Flyer still offers the old-style front for their buses. ABQ RIDE's DE60LFs that were delivered in February of 2007 still featured New Flyer's "classic" front, even though the first buses to feature the restyled front end were introduced in 2005. However, the first DE60LFRs (DE60LF with restyled front end) were delivered to Hamilton Street Railway in Hamilton, Ontario last April.
 
cfalk
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 8:57 pm



Quoting Klaus (Reply 4):
Buses running in city traffic are the perfect example of the kind of stop-and-go operation which should profit the most from hybrid drive - provided they can use regenerative braking effectively instead of constantly and uselessly turning motion into heat with conventional brakes.

Agreed. Hybrid makes no sense in sprawling suburbs - I have a friend with a Prius here in Kentucky, and the gas engine's running nearly the whole time, but in compact cities (I'm thinking London, Paris, NYC) they would be perfect.

I would like to see a London double-decker hybrid...
 
A342
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 9:00 pm

While I'm quite a diehard diesel fan, I must admit that CNG burns way cleaner than diesel. ULSD doesn't really change that. CNG is also advantageous because it's cheaper than diesel, at least here in Germany. That's why my hometown has something like 85% CNG buses now, and the last diesels are set to go.

I believe hybrid technology will make a real breakthrough when hydrogen and fuel cells become financially competitive. They are just more efficient than internal combustion engines.
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 9:06 pm

Quoting A342 (Reply 35):
While I'm quite a diehard diesel fan, I must admit that CNG burns way cleaner than diesel. ULSD doesn't really change that. CNG is also advantageous because it's cheaper than diesel, at least here in Germany. That's why my hometown has something like 85% CNG buses now, and the last diesels are set to go.

Actually, according to New Flyer, diesel-electric hybrid buses burn cleaner than CNG buses, and provide much better fuel economy.

http://newflyer.com/pix/Brochures/hybridbrochure.pdf

Here in Albuquerque, CNG is going by the wayside. ABQ RIDE currently operates 75 CNG buses (40 Neoplan AN440 CNGs and 35 Thomas/Dennis SLF200 CNG buses), however, all future orders for ABQ RIDE will be diesel-electric hybrids. The SLF200s' poor performance and reliability is what basically caused ABQ RIDE to give up on CNG.

And note that in the North American market, only NABI currently produces CNG articulated buses.

[Edited 2008-01-29 13:11:40]
 
cfalk
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 9:07 pm



Quoting A342 (Reply 35):
I believe hybrid technology will make a real breakthrough when hydrogen and fuel cells become financially competitive. They are just more efficient than internal combustion engines.

Uh... Why would you want a hybrid powertrain (i.e. two engines) if you have fuel cells or run on hydrogen?
 
A342
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 9:14 pm



Quoting 1337Delta764 (Reply 36):
Actually, according to New Flyer, diesel-electric hybrid buses burn cleaner than CNG buses, and provide much better fuel economy.

I'm not doubting fuel economy, but European manufacturers have found out that CNG is cleaner. Of course, you can make a diesel very clean, but it takes quite an effort.

BTW, are there any CNG hybrids out there?

Quoting Cfalk (Reply 37):
Uh... Why would you want a hybrid powertrain (i.e. two engines) if you have fuel cells or run on hydrogen?

I don't get your point. Maybe you could re-phrase that?
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 9:41 pm

Quoting A342 (Reply 38):
I'm not doubting fuel economy, but European manufacturers have found out that CNG is cleaner. Of course, you can make a diesel very clean, but it takes quite an effort.

BTW, are there any CNG hybrids out there?

Cleaner than regular diesel buses? Yes.

Cleaner than diesel-electric hybrids? NO.

I seriously doubt that New Flyer would be fabricating this data. Please read the provided link again. If you don't have Adobe Reader software, then I will provide the data for you

NOx g/mile:
  • Diesel - 30
  • CNG - 20
  • Diesel-electric - 18


PM g/mile:
  • Diesel - 0.24
  • CNG - 0.10
  • Diesel-electric - 0.09


Combined with the fact that diesel-electric hybrids get about double the fuel economy of CNG buses, diesel-electric hybrid technology truly wins over CNG. One manufacturer in North America, Gillig, doesn't even produce CNG buses.

[Edited 2008-01-29 13:43:08]
 
glid4500
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 9:52 pm



Quoting ThreeIfByAir (Reply 13):
King County Metro (Seattle) has the largest hybrid fleet in the US, all DE60LF units from New Flyer

KC Metro has the larges hybrid articulated bus fleet.
MTA-New York City Transit has the largest 40ft hybrid bus fleet in the nation so far

Ive actually seen a few of those DE60LFs in albuquerque before...and was amazed of the amount of soot coming from the exhaust.

Im glad that NewFlyer developed Gasoline Electric hybrids. Ive driven them quite a few times. They perform like any other hybrid minus the soot from the exhaust. Unleaded has hybrid or fuel cell is prolly the way to go if agencies dont wanna invest in CNG / LNG or ETBs.
 
cfalk
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 9:55 pm



Quoting A342 (Reply 38):
Quoting Cfalk (Reply 37):
Uh... Why would you want a hybrid powertrain (i.e. two engines) if you have fuel cells or run on hydrogen?

I don't get your point. Maybe you could re-phrase that?

A fuel cell is basically an electrical generator, and output can be varied to determine how much voltage and amps you want it to generate. Why would you want to shut down the fuel cell and run on batteries? All you do is increase the weight of the car. Not to mention that a fuel cell is kinda tricky - you don't want to shut it down all the way if you can avoid it, because it takes a while to start up again, unlike a normal engine.

As far as hydrogen is concerned, fuel cells run on hydrogen, as well as other kinds of engines, so what kind of engine are you talking about specifically? Also, where does the hydrogen come from - cracking hydrocarbons (oil) or some other source which is currently very inefficient, but we hope to figure that problem out one day.
 
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1337Delta764
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 9:59 pm

Quoting Glid4500 (Reply 40):
Im glad that NewFlyer developed Gasoline Electric hybrids. Ive driven them quite a few times. They perform like any other hybrid minus the soot from the exhaust. Unleaded has hybrid or fuel cell is prolly the way to go if agencies dont wanna invest in CNG / LNG or ETBs.

Beware the fact that gasoline, even though burning with less soot, produces more carbon monoxide than any kind of diesel fuel, regardless of whether it is ULSD or not. Carbon monoxide becomes CO2 when entering the atmosphere, contributing more to global warming.

The only real reason why New Flyer offers gasoline electric hybrid buses is due to very strict emissions standards in southern California for diesel engines, regardless of ULSD or hybrid technology. The New Flyer GE40LF is only produced in 40-foot length, and I don't think it is available yet with New Flyer's restyled front end.

If gasoline-electric is the way to go, how come the majority of TAs buying hybrid buses are going the diesel-electric route? Even NYCT/MTA Bus operates and continues to order Orion VII HEVs.

[Edited 2008-01-29 14:03:49]
 
Klaus
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 10:06 pm



Quoting Cfalk (Reply 41):
A fuel cell is basically an electrical generator, and output can be varied to determine how much voltage and amps you want it to generate. Why would you want to shut down the fuel cell and run on batteries?

Because the electrical energy you're re-generating while braking needs to be stored somewhere until it can be used for acceleration again.

I would also expect that buffering the output from the fuel cells against the widely varying load would increase their efficiency as well.
 
cfalk
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 10:09 pm



Quoting Klaus (Reply 43):
Because the electrical energy you're re-generating while braking needs to be stored somewhere until it can be used for acceleration again.

I would also expect that buffering the output from the fuel cells against the widely varying load would increase their efficiency as well.

You don't need big heavy batteries for that. Capacitors will do quite nicely.
 
Klaus
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 10:39 pm



Quoting Cfalk (Reply 44):
You don't need big heavy batteries for that. Capacitors will do quite nicely.

Batteries have much larger capacities per weight.
 
LASoctoberB6
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 10:42 pm



Quoting 1337Delta764 (Reply 33):
I also believe that New Flyer still offers the old-style front for their buses.

I am aware of that...
 
N231YE
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 10:55 pm



Quoting 1337Delta764 (Reply 42):
Beware the fact that gasoline, even though burning with less soot, produces more carbon monoxide than any kind of diesel fuel, regardless of whether it is ULSD or not. Carbon monoxide becomes CO2 when entering the atmosphere, contributing more to global warming.

Kinda...Catalytic Converters are supposed to change CO into CO2.

Quoting Cfalk (Reply 37):
Why would you want a hybrid powertrain (i.e. two engines) if you have fuel cells or run on hydrogen?

If you understand how electric motors work, apply current to the motor, it will output motion. But when motion is reapplied to the motor, it acts as a generator, and outputs current.

So, when decelerating, instead of wasting heat through dynamic braking like a locomotive, or just plain heat like a automobile's brakes, why not use this property of the electric motor to recapture this energy, and "reapply" it to the automobile when accelerating.

As for the batteries, while I agree with you, that ultra-capacitors seem to be better. Interestingly enough though, Honda swapped the ultra-capacitor in the FCX for a Li-Ion battery in the Clarity. So either the technology for super-capacitors is still in its infancy, or there is something more underlying in that Honda believes that batteries are better. Why they did this, I do not know.
 
Dougloid
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 11:03 pm

One of the companies I worked for back in the day (Garrett) did some work on the flywheel bus...

http://en.wikipedia.org/wiki/Gyrobus
 
Klaus
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RE: Are Diesel-electric Hybrid Buses Worth It?

Tue Jan 29, 2008 11:24 pm



Quoting N231YE (Reply 47):
So either the technology for super-capacitors is still in its infancy, or there is something more underlying in that Honda believes that batteries are better.

Modern batteries are still lighter and more compact for the same capacity.

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