Repower Conversion

[NewbeeMC9]

My new repower plans,  first I have to convert the 8V71 to run on ethanol.

http://www.greencarcongress.com/2007/05/scania_to_unvei.html



Maybe you can can help me on this one Chaz.    

[Ncbob]

Good Luck with that one, John.  At a 28:1 Compression ratio I'm wondering what's going to keep the cylinder heads on that thing once they stuff the ethanol into it?

And traction motors?  I see a lot of weight for 270 HP to be pushing around.....

Bob

[belfert]

I didn't notice if they published the weight of the bus, but transits are likely to be lighter than a highway coach.  A lot of transit buses have been powered by Series 50 engines at 270 to 330 HP.

I think the big deal here is the electric motor(s).  Electric motors generally have a very flat torque curve so they generate that torque at any RPM unlike most diesels.  Folks building their own electric cars often destroy drivelines because the motors have so much torque.

[Kristinsgrandpa]

More on hybrid buses......

Back to Industry News
Napa School District receives California's first plug-in hybrid school bus


In Napa, CA, the Napa Valley Unified School District will begin the 2007-08 school year with a new plug-in hybrid diesel-electric school bus from IC Corporation that could help offset increasing fuel costs and protect the environment. More than 150 attendees will be on-hand Friday at a ceremony in Napa when the hybrid school bus is officially delivered.



The school district is one of only seven school districts in the U.S. – and the first in California – to operate the new plug-in hybrid school bus that has the potential to double fuel efficiency and reduce emissions by up to 90 percent.



Manufactured at IC Corporation's plant in Conway, AR. IC builds the hybrid plug-in school bus in conjunction with Enova Systems, a provider of hybrid drive systems. The new bus is a result of a nationwide initiative called the Plug-In Hybrid Electric School Bus Project led Advanced Energy, Raleigh, NC, a non-profit corporation that initiated a buyer's consortium of school districts, state energy agencies and student transportation providers.



Bringing the hybrid school bus to Napa is the result of strong local support and funding from the Bay Area Air Quality Management District, the Environmental Protection Agency's Clean School Bus USA program and Pacific Gas and Electric Company (PG&E). The Bay Area Air Quality Management District contributed $100,000 and

PG&E provided $30,000 to help with the purchase of the plug-in hybrid school bus.



In April of 2007, PG&E showcased the first-ever utility Vehicle-to-Grid (V2G) technology demonstration in the Silicon Valley and, in June, PG&E announced it had also teamed with Google to bring plug-in-hybrid technology to its Mountain View campus.



An additional $30,000 to fund the bus was provided by the U.S. EPA through the Clean School Bus USA program and the West Coast Collaborative, a public-private partnership to reduce diesel emissions.



The hybrid school bus project features Enova's Charge Depleting System (or "Plug In"), which was extensively tested and evaluated at IC Corporation's research and technology facility in Fort Wayne, IN. With an overnight charge, this system uses a larger battery based on advanced battery chemistry that provides stored energy intended to be drawn down over the driving cycle, thus optimizing fuel economy. In other words, the bus will use a diesel engine to operate, but the electric battery will activate when needed to reduce the amount of diesel fuel used to power the engine.



The powertrain for the hybrid school bus will couple a MaxxForce 7™ diesel engine with the 25/80-kilowatt hybrid-electric powertrain, incorporating a transmission, batteries and an electric motor. The system is based on a parallel architecture, allowing the system to run on both diesel and electric power in a highly efficient manner. The hybrid bus is also configured to run on biofuel blends to increase its environmental performance.



Later this year, other school districts around the country will be receiving the remaining IC Corporation hybrid school buses awarded in Advanced Energy's bid. By the end of 2007, 19 hybrid school buses will be in operation because of Advanced Energy's consortium.



The following members of the buyers' consortium have received or will be receiving hybrid school buses:



Napa Valley Unified School District, Napa Valley, Calif. (1 bus) -- DELIVERED

Lake Chelan School District, Chelan, Wash. (1 bus) -- DELIVERED

Little Rock, Ark., School District (1 bus) -- DELIVERED

North Carolina Department of Public Instruction (2 buses) -- DELIVERED

Jennings Transportation, Nazareth, Pa. (1 bus) – DELIVERED

Florida Department of Education (2 buses) – DELIVERED

South Carolina Department of Educations (2 buses)

State of New York (2 buses)

Durham School Services, Everett, Wash. (1 bus)

City of Seattle (1 bus)

Sigourney Community School District, Sigourney, Iowa (1 bus)

Nevada Community Schools, Nevada, Iowa (1 bus)

Killeen Independent School District, Texas (1 bus)

Austin Independent School District, Texas (1 bus)

Fairfax County, Va. (1 bus)




Back to Industry News

[NewbeeMC9]

Good Luck with that one, John.  At a 28:1 Compression ratio I'm wondering what's going to keep the cylinder heads on that thing once they stuff the ethanol into it?

And traction motors?  I see a lot of weight for 270 HP to be pushing around.....

Bob

I was depending on you to hook me up with the generator!  and the beer, and the moral support

Beer and moral support is about as far as i'll get any way   Isn't it the thought that counts?  we'll have a beer and think about it.

The 270hp/885 foot-lbs is probably a little better than what I'm pulling right now.

Traction motors?  your right, let's use friction motors instead,  just get out and give it a push and roll for  awhile

just thought it was interesting and worthy of beer talk.

[Fred Mc]

Where the heck is NAPA going to get the electricity to run buses. They don't have enough power now for all the air conditioners.

Fred. Mc

[Barn Owl]

This is what my company is testing:

http://www.greencarcongress.com/2005/02/epa_eaton_and_p.html

It is more of a transition type of technology that's no so exotic as to never make it.

[Stan]

This is a strange system. The International Maxxforce 7 engine is rated 200 - 230 HP but the electric drive train is only 107 HP. It certainly won't peel rubber at the lights.

Fred makes a good point. Why is PG&E financing a system that will use more electricity, when they can't meet the demand now? Would they be using this to get quick approval for less than desirable new power plants?

[Charles Seaton]

While our hobby is still alive and kicking, it is being nibbled at around the edges.  The growing number of Hybrid/Electrics and low-floor buses will, at some point, take away the transit option for those of us who like a lower cost coonversion.  While Hybrid is interesting, they get better MPGs in the city than the highway.  We use them as transits, here in NYC but all of our express coaches are OTR MCIs with series 60.

[H3Jim]

I think the higher cost of fuel is nibbling (ok, biting) much harder at our hobby than a change in what some of the transit auth are running.  There is not a lack of inexpensive old buses to buy.

[Lee Bradley]

Well I guess it is a hybrid of a diesel/electric system; not like the hybrid cars we are seeing with a electric motor assisting the gas engine. The diesel/alcohol engine can run at optimum rpm all the time with power going to the drive motor, supercapacitors, AC, resistive heat, etc. During acceleration, power is supplied to the traction motor from the motor/generator and supercapacitors. Using the standard HP formula for gas/diesel engines, the traction motor makes between 600 and 900 HP. BIG equipment has used motor/generators, without the supercapacitors, since the 1930s. Well proving technology. We should see motor/wheels in the future; much better system than motor and rearend.

[Stan]

Lee: I assume that you are referring to the Euro bus when you say "Using the standard HP formula for gas/diesel engines, the traction motor makes between 600 and 900 HP." Does this mean that the bus gets 270 HP from the diesel engine and up to 630 HP from the super capacitors?

The link says that it uses a 150 KW traction motor which is only 201 HP (150 x 1.341) so where is the extra HP going? What am I missing?

[Lee Bradley]

HP is pretty slippery. Using the watts to HP you are correct. Using brake HP it is torqueXrpm/5252, 2028X2400/5252 = 927HP.  Yes the supercapacitors make up the additional power requirement so you have the power to get moving without the huge engine it would require normally. I didn't see it in the story but hopefully the system also uses regenerative braking to put braking energy back into the supercapacitors.