November, 2003 (posted on the net, July 1, 2004)
ISE Thundervolt.
... I rode on 2 Hybrid Buses.... One powered by Ford Gasoline engines and Maxwell Ultracaps, the other powered by Cummins Diesel engines and Zebra Sodium Nickel Chloride (NaNiCl) Batteries
Edited Interview Excerpts and Notes:
ISE Thundervolt: Joshua Goldman
Evworld.com: Josh Landess
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Part 1. Gasoline/Ultracap Hybrid Bus
EVworld: Can you just give me a brief rundown of what makes this different?
Josh G: This is a gasoline hybrid electric power train. This is the pre-production model for the fleet of buses that are going to be running in Southern California. What we’re looking at here is a Ford Triton V10 engine, which comes to us with a ULEV rating. It’s mated to a Siemens Alpha Drive system.
EVworld: Is that why you went with gasoline and not diesel -- because you can get the low emissions?
Josh G: Exactly. ... So it’s mated to a Siemens Alpha Drive System, which includes a hundred and forty kilowatt generator. It has two inverters each one is capable of two hundred and eighty kilowatts.[?]
EVworld: What kind of torque?
Josh G: We have twin Siemens Alpha Drive motors. Eighty-five kilowatts nominal, a hundred an forty kilowatts peak, on each of them. The whole bus is capable of twenty-eight hundred Newton-Meters right off the line. ... but you need a lot of torque to get a bus moving. We have an energy storage system on the roof of the bus, which is a set of [two] two-packs each with a hundred and forty-four Maxwell Ultracapacitors.
EVworld: And I see from your literature there is an option of batteries instead of ultracaps?
Josh G: The bus that’s in front of us, that’s the diesel hybrid powertrain, with three Zebra Batteries as the energy storage system. Zebras are Sodium Nickel Chloride batteries.
EVworld: So you’re showing two different options here, what you can do for people.
Josh G: Correct. And you can configure different parts from each one. [You may want] Zebra Batteries, which give you a longer All-Electric range, or if you want the Ultracapacitors which give you a faster launch, and a little bit better efficiency across energy source system.
EVworld: I’m noticing that these aren’t General Electric. That’s interesting because they just had that demonstration of the hybrid bus in Albany. And somebody was pointing out to me that if you have any all-electric range on a bus it’s superb because anyway you can get the emissions down in a city environment, bravo.
Josh G: What we’re seeing right now is tailpipe emissions with the gasoline gen-set are so clean that in terms of particulate matter it’s actually cleaning the air here in some parts of L.A. In terms of NOx, we’re still in the realms of parts per million in terms of the grams per mile coming out of the tailpipe.[...] it’s tough to measure in most of the operating range, there’s a little bit under accelerations, but the bus is so clean and quiet that we see this as real alternative to really the All-Electric capabilities (Inaudible). And with the cost of energy storage systems and their durability over the heavy-duty cycle of a bus, having a good, clean, quiet, gen-set with a set of efficient ultracapacitors for your stops and goes, we see as a really efficient and most cost-effective way.
EVworld: Any combination of all three? Including batteries and ultracaps on a bus?
Josh G: Those are possible. Again it comes into cost, and we really need to start getting these systems down where they can start competing with certain CNGs and even the Diesel buses. So that’s where this whole power train got developed, and the whole thing’s got to be packed to fit inside a low-floor chassis like you see here. In fact all the equipment that’s on the rooftop will fit into the rear A-track compartment and then you can go with rooftop air conditioning like you see on a lot of the buses riding around in Long Beach. And they have all electric rooftop air conditioning available.
EVworld: I was just on the GM [Hybrid] Bus, and they’re pretty close to delivering to Seattle, I guess. [...] Approximately where is this project in terms of delivering something to somebody?
Josh G: We’re going to have the first two units off the plant come this summer, and then we’re going to deliver the bulk of the twenty-seven buses in December of ’04.
EVworld: Where to?
Josh G: To Long Beach, California right here. They’ll be the first customers. Then there’s going to be twenty or so more to other Southern California transit agencies (like Norwalk, Montabello, Orange County, San Bernadino have taken some), and they all have options for hundreds more after that, after they see how these perform. We’re going next week, taking this bus first to the main factory in (Inaudible) so they can put on their testing stands. And then we’re bringing it at the start of next month to the Altuna test track, which is a heavy-duty bus test track in Pennsylvania, where they run the bus over railroad ties, and cobblestones and shake down the entire system for fifteen thousand miles to simulate the first four years of life of the bus. After we pass that, we get all our data back, and we’ll be producing these things in San Diego for New Flyer as well as other bus manufacturers.
EVworld: Producing the power train or the whole bus?
Josh G: The cradle. The cradle power train.
EVworld: And the buses are manufactured by anybody they specify, or...?
Josh G: Well this particular model is a New Flyer bus, but we have different configurations of the cradle here that will fit into either a (Inaudible) bus or other manufacturers. The other biggest news and most important is that this is the first hybrid-electric, heavy-duty power train certified for use in California 2004 to 2006. The only certified hybrid system for a forty-foot bus of this size.
EVworld: Somebody told me that ultracaps have a problem where if they burn they emit dangerous fumes.
Josh G: These come with a integrated fire suppression system, which has the chemicals in order to be able to counteract the dangerous fumes. (Inaudible). And keep the packs on the roof or the upper compartments of the bus so if there is a safety problem, it has a way to vent out and we also have monitoring of all the electrical drive systems as well as passive controls on the ultracapacitors to keep them in range so that they don’t get to those unsafe levels. The worst part about capacitors is getting it too high in voltage.[...]And so we add a safety factor in our control system to not get the voltage ranges where they can become unsafe.[...]
[...] Well we have integrated packs that are ready to drop into a vehicle, (Inaudible) you can put them in series to make six hundred volts like we have on the bus. They give you about close to half a kilowatt-hour of power. And they do a good launch, in fact inside of Maxwell who gives us the ultracapacitors for this vehicle, worked with Brigham Young University ... Which is their drag-race car, an EV1 converted.
EVworld: Here’s my reason I’m pressing on this, I did an interview with Mr. Smith a couple of years ago at Maxwell, and this didn’t really come up, and now if it’s going to come up I want to tell readers about it. [...] I want to get a balanced view point about what exactly the issues are, or are not.
Josh G: I agree you’re not the first to mention this from our standpoint with all the testing we’ve done so far and we have one of the packs on the shaker table right now to go through it’s chemical connections to make sure those are all safe, full diagnostics, and we have all the data from Maxwell for it’s own safety characteristics, but in terms of the actual hazard analysis you really need to talk to them. [...] That’s all I can tell you, that from the experience we’ve had with the capacitors up on this roof as well as an older generation capacitor package we have in operations in San Bernadino, they’ve proved safe, reliable and very efficient for use in a hybrid bus.
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EVworld: May I ask Mr. King [a representative of a competing bus project who was with us taking a test-ride, Aerotech, not with ISE] what caps you’re using? Or are you guys not saying at this time?
MR. KING: We’ve evaluated many different ones throughout the world, so I guess I could say that. And both in laboratory as well as in vehicles. [...] Right, okay. The current ones are Nescap.
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[...discussion of which bus we are to take on a test drive first...]
Josh G: [The Ultracap-Equipped bus is] my favorite bus to drive anyway, it’s a little bit faster. Which bus drivers always like. Yeah we integrated with (Inaudible) transmission shifter, reverse-engineered the shifter so we could use the standard shifter that bus drivers are used to. Everything else, the rest of the controls of the vehicle, are identical, including the start button, which starts the engine just like they’re used to.
MALE: Do you have any issues with, how are most of your Transit Agencies [about using] diesel or gasoline? Is that an issue?
Josh G: Well, actually a lot of the Transit Agencies in Southern California are either converted to or looking to convert to alternative fuel. That primarily being natural gas, either CNG or LNG.
EVworld: I want to see bio-diesel.
Josh G: Really, what it comes down to is emissions. And the emissions requirements are so stringent in California that there’s not a diesel engine out there that’s certified for a low-emission use in a hybrid or otherwise in California. We just got certified using the gasoline engine due to its ultra low emissions to point four grams NOx per (Inaudible) per hour which lowest certified system (Inaudible) California and the only one that’s certified for sale for 2004, 2006 in a heavy-duty bus of this size.
EVworld: Somebody ordering a diesel in another state might be okay?
Josh G: Yes, in fact this diesel hybrid is one of three for New Jersey transit.
EVworld: Why did you choose the Zebra Batteries for that?
Josh G: Power to weight, or energy to weight.
EVworld: What did you say the chemistry of that is?
Josh G: Sodium, nickel, chloride. ... Or 'salt' battery.
EVworld: Do they have good durability lifetime that sort of thing?
Josh G: They give us a two year warranty right now, Maxwell is giving us a five year warranty on the capacitors because they show lifecycles in the order of half a million cycles, which, those ranges should be able to last the life of the (Inaudible.... 12 yr?) bus.
[The bus ride started at this point ... he was driving in a crowded area (which is a feat in itself) while answering questions, and at times it was too loud for accurate transcription of the recording. The bus we were on for this first ride was the Gasoline-Ultracap Hybrid, not the Diesel-Battery Hybrid.]
EVworld: How much EV-only mode is there in the [other bus] Zebras?
Josh G: Five to fifteen miles depending on how many zebras packs are used.
EVworld: Do you have it programmed like the GM bus where, below a certain speed you can do EV-only mode, and above that [you can have the] engine kick in or?
Josh G: Well, the way it works is it's power not speed. So much like the Toyota Prius with which you're familiar, the harder you step on the gas peddle the sooner the engine kicks on. The same is true for the diesel hybrid. And in this hybrid for that matter, for current certification you need the engine up and running, while a new emission system is developed for the engine (Inaudible).
[....]
Josh G: All right hold on. [Sound of bus accelerating.]
EVworld: Yeah, that’s a pretty good pick up huh?
Josh G: (Laughing)
EVworld: Well I’ve always been amazed simply at the job of being a bus driver.
Josh G: [sound of braking] (Inaudible) and it’s All-Electric, no air brakes.
EVworld: Is it?
Josh G: The caps all the way up and all the way down (Inaudible). All-Electric.
EVworld: Are you on the brakes during that time or you’re just letting off the gas?
Josh G: Letting off the gas for (Inaudible) and then when I hit the brake depending on how hard I hit it it blends in more electric retardation. (Inaudible) and push really hard it still has the air brake system that we minimize it’s use and try to increase the brake life. [(Inaudible): It's always be there for safety reasons.]
EVworld: You need it also for those last few miles per hour no?
Josh G: No.
EVworld: You can do all, theoretically brake all the way to zero?
Josh G: Not theoretically, it does.
EVworld: It does brake just with the electromagnetic fields?
Josh G: Yes, it sure does.
EVworld: I was talking to the Allison guy about how they were doing theirs, and they were also obviously doing regen. They talked about traditionally the fact that bus drivers have retarded braking built in anyway.
Josh G: Yes, that’s what we’ve got. We have, in the event that the under storage system is full, coming from a long downhill or a higher speed stop, we employ electric braking resistors which are water cooled (Inaudible) they blend in with the ultracapacitors (Inaudible) retardation on the driver.
EVworld: What’s the number on how much energy you’re 'recycling' as it were when you take a large vehicle like this from sixty to zero?
Josh G: Well, we don’t really go to sixty in a bus that often. The number that we look for is forty to zero.
EVworld: How many kilowatt-hours are being saved instead of thrown away?
Josh G: Well, I think over a sixteen hour day, which is a typical transit bus cycle, we’re getting about seventy kWh... seventy to ninety kWh. Those numbers are all in development as we go through the final stages. [inaudible] Experiencing the ultracapacitors.
EVworld: Is that somewhat more efficient than you’re getting with regen braking in batteries?
Josh G: Yes, we’re showing ninety five percent in and out with capacitors.
EVworld: Interesting.
Josh G: [at slow speed]And this is quiet for a bus. (Inaudible) power and passengers like how quiet it is.
EVworld: Now that you point it out, yes.
Josh G: I mean if you’re sitting here hearing the air bags leveling it’s pretty quiet. And you don’t also have the grumble of a diesel. Which has a lot of vibration to a chassis.
EVworld: All I really hear is sort of an electric motor whine, I guess. It was Siemens equipment back there. Is the motor itself Siemens?
Josh G: All the electric motors are Siemens supplied except for the accessory drive motor which is a off-the-shelf motor modified to our configuration to give dual out put shafts [by ruling] and it drives up the backside hydraulic pump for the power steering of the bus and on the front clutches in the air compressor for the air system. It’s the fastest [airfill] that we’ve seen also on a bus. It also allows us to keep the hydraulics and [air] up irrespective of engine operation in the idle stop configuration.
The air conditioning is also an electric air conditioning unit. The bus over here is configured with a hundred and twenty thousand BTU rated compressor. This one’s eighty-five thousand BTU. And again the idea being, to be able to keep the engine doing what it’s designed to do, which is just turn the generator and provide power to the batteries or to the drive system. The drive system is also designed to allow for gas and electric mode of operation in the event that there is any sort of problem with the energy storage system, it’ll flash a “check engine” light and our onboard diagnostics unit will send an email through the cell phone antenna back to the shop to let them know that they need to check the energy storage system when the bus pulls in, but we’ll take the energy storage off-line and just run straight power from the engine right to the drive system.
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Part 2. ISE Diesel/Zebra Battery [Hybrid] Bus
MALE: So the Zebra Batteries are on the roof?
Josh G: Underneath.
Josh G: [...] Right. I guess that's a disadvantage of the sodium, nickel, chloride is they fit nicely underneath and it’s easier to take them out from there. If you had to package them on the roof. It could get a little tricky.
EVWorld: Are they that heavy?
Josh G: Well the weight is one, and the idea is that they have to take them out to replace it with a fresh pack.
EVWorld: I see.
Josh G: And ...typical refueling times is three to five minutes, that includes fueling it, checking all the fluids…cleaning the inside of the bus.
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[The following discussions took place while Josh drove the Diesel/Battery Hybrid bus on our second test drive of that day. Some of the discussion was inaudible for transcription on the digital recording because of the sound of the bus.]
Josh G: This one does have the newest Cummins [inaudible] engine. So it's the cleanest Cummins Diesel out there, but it’s still probably five times dirtier than the gasoline. (Inaudible due loud bus noise... Bus ride begins in background) Good pickup for a diesel. It will out-accelerate in the 0-40 range the standard vehicle buses that New Jersey has.
MALE: It’s quieter than a standard diesel also.
Josh G: Yes, it’s much quieter back there.
MALE: Although it does seem a little noisier than the gasoline version.
Josh G: Right. (Inaudible). A lot more mass.
EVWorld: Either one of these buses we’ve been on I never really would guess it was a hybrid and you know immediately maybe after awhile I would think, but they just seem like buses, you know?
Josh G: And that’s the idea for the driver. We went to drop off these buses in Long Beach, and the driver said “Hey, can we drive them?” [We said], “Oh yeah, yeah.” [He said], “Well what do I gotta do?” [We responded]: “ Hop in, start it like you usually do, and…”
Both Buses Are Series Hybrids
EVWorld: Maybe this is the wrong question, but what kind of mechanical transmission is in here?
Josh G: Well, it's a series a hybrid. [...] Standard set up differential in the bus, and then it has a pair of Siemens Electric motors through a gearbox to drive the differential. And then it's got the [Cummins Diesel] mated to a Siemens forty-kilowatt generator and all it is, is a bunch of inverters and wires between them.
EVWorld: Same thing with the other bus: A Series Hybrid?
Josh G: Yes. We found that series hybrids are a bit more efficient for the stop and go cycle of a transit bus. Parallel hybrids seem to do better on the highway type cycles.
EVWorld: Interesting, because the GM guy was telling me how he thought parallel hybrids were the way to go for efficiency, but I think there’s more than one side to that discussion.
Josh G: We have experience integrating the Allison system. GM actually invited us to integrate it for some motor coaches for (inaudible).
EVWorld: Is this all-electric right now, what we’re doing?
Josh G: No, the engine just kicked on.
EVWorld: Just wondering what that noise was.
Josh G: So it’ll come to a stop and really it just kind of depends upon where the batteries are. I couldn’t tell you where the batteries are because we don’t have any sort of gauges to the driver. We have a diagnostic system again with the [attendant]. In fact, you could probably go inside and go to our kiosk there and he could tell you how the battery’s doing on the bus, but I couldn’t.
MALE: You said the EV range is a function of how many batteries you have in?
Josh G: Yup. EV Range and power is a function of how many Zebras you configure, and the Zebras are pretty much good for about five miles a battery.
MALE: Per Zebra Battery?
Josh G: Per Zebra Battery.
MALE: And then you’d have multiple batteries, is that what you’re saying?
Josh G: Right, in this bus we have three.
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[Closing discussion of Costs, and some pros and cons of both bus approaches]
Man: So then the alternator cranks the engine, or do you have a separate?
[Editorial Side Note: I believe he said the bus shuts off when you pick up passengers, but I may have been mistaken.]
Josh G: The generator, yes. It starts and stops the engine. (Inaudible) ... (Inaudible) ... And it drives the wheels, and complete the package and for sale and distributed for Siemens in the United States.
EVWorld: Does this sort of thing cost a premium over comparable buses from regular manufacturers?
Josh G: It’s about twenty to forty thousand dollars more than a typical Siemens (Inaudible), kind of depending on the configurations. And eighty to a hundred thousand dollars more than a diesel.
EVWorld: And then theoretically you could save how much gas over a say a year or so?
Josh G: We see paybacks times for the cost of the system around (inaudible) to three years. Kind of depends on what you compare to, because the problem is with CNG that there’s a very high infrastructure costs. The cost is about three million dollars to install one [inaudible plus another] million dollars a year to run it. So a small transit agency is forced to go alternative fuel and they have a choice between gasoline hybrid which costs them another forty thousand dollars a bus versus three million dollars to install a station for a CNG. A lot of them are now picking gasoline hybrid.
EVWorld: For the battery replacements?
Josh G: [Use a] forklift.
EVWorld: Percentage-wise what kind of mileage improvement is there?
Josh G: We’re seeing anywhere from thirty to fifty percent. Depending upon energy storage and route cycles. We’re getting right now on a standard bus route about close to six miles per gallon. On route on the buses in New Jersey I think that bus should be up and running, you might be able to see it again in the kiosk, on our display. And the standard diesels which are on the same route which are thirty foot diesels, are getting about four miles per gallon.
EVWorld: Any dependence on the weather if it gets really cold, does that affect it?
Josh G: With the Zebra Batteries and the Ultracapacitors, they're both ambient air cooled. And zebras are rated from the manufacturer from minus forty to plus fifty C ambient air temperatures. The ultracapacitors manufacturer rated minus thirty-five to plus sixty-five C ambient air. So all we have is standard twelve volt cooling fans on these suckers to push the air through. Not a problem. The chemistry of the zebra battery is such that they’re what I call a “hot battery”. Salt chemistry at room temperature is in solid form. It doesn’t start turning to liquid until about two hundred and seventy C, that’s when you can start utilizing the electrolyte for the battery.
So the batteries stay warm, they’re encased in a vacuum packed ceramic housing. Which acts like a thermos on the batteries, so once they’re heated up they stay warm to up to about a week depending upon how hot it is outside. And if they start getting cold it gives a warning and you plug it into the wall to run a heater inside it. To keep it warm. But one nice advantage of that is in terms of what you said the infrastructure being able to handle the battery. Once it cools down, it goes to solid form and there’s no degradation over time for that battery. So you can keep a battery on the shelf for years at a time without any degradation. And then you just plug it in, it comes with a built in charge you plug it into the wall and it heats up in a day. And it’s ready to be installed onto the bus.
The ultracapacitors, well their configuration to get charged up they have a passive equalization system. We bring the capacitors down in voltage to safe levels, close to zero volts, every night. And then use the engine to charge them back up. When the driver first turns it on, it all happens within the first minute. The idea being there is the capacitors lasting longer at lower voltages, and you can only keep them live and active when they need to be used. They're safe.
EVWorld: The batteries on this bus it sounds like they’re doing pretty serious business. It’s not just about a little bit of electricity coming in and out for a regen thing, but it’s also they retain a lot of energy above and beyond that. In other words when I think of an ultracap, not really expecting much out of it except when you hit the brakes you’re storing energy and when you get on the gas you’re using it and it’s the energy density is not huge.
Josh G: Right. Power density is.
EVWorld: Right. So the battery is you’re storing a pretty goodly amount of energy?
Josh G: Yup.
EVWorld: How are they doing on the regen part -- just the power intensive part?
Josh G: Each pack is worth thirty kilowatts of regenerative capability. Thirty to forty kilowatts depending upon its conditions. So you get anywhere from ninety to a hundred and twenty kilowatts braking with the three packs we have here.....versus the ultracapacitors which are capable of two hundred kilowatts and that’s just limited by us.
EVWorld: Even though that’s your strength you’re still doing pretty okay with the batteries for regen braking.
Josh G: Oh yeah.
EVWorld: Okay..
Josh G: But, again it’s a life cycle cost. Here we hope to get two and a half three years out of these batteries, testing will prove itself. And they cost about right now ten thousand dollars each.
EVWorld: Doesn’t seem like very much money. I don’t know how many are used in a bus.
Josh G: Well we have three in the bus. That’s thirty thousand dollars in energy storage system.
EVWorld: Okay.
Josh G: And the ultracapacitors pack is about twenty thousand dollars, but it's warranted by the manufacturer for five years, but [inaudible] time will tell if it will last the life of the bus. ... So that means you’ve gotta pick your ideas, and yes maybe there’s a combination out there that could work. We have some batteries as well as ultracapacitors you can get that all-electric range. You can get that going through the tunnels without any emissions. But the way we’ve really seen it, that V10 [Ford Gasoline] engine is so clean. ... that it's almost tough to warrant the added cost of more batteries. ... And you get [the engine] right from the factory. It comes with a warranty associated with it.
EVWorld: And the batteries in this bus are just being charged and recharged from the engine until they degrade in some way? When you brought up the issue of taking them in and out of the bus I didn’t know how often that happens. If it’s days or years.
Josh G: Years. [...] “Check Engine” comes on. (Inaudible). And they have an integrated controller that monitors everything inside the batteries. One other advantage of the foreign (Inaudible) chemistry is if you get a short in the battery, typically a short in a standard chemistry battery of nickel chloride or a lead acid, the short’s open. Chemistry of the salt battery, if the short’s closed which means you can have a failed cell but you can still operate the pack. And it just comes down to how many failed cells do you allow before say the entire pack needs to get sent back to the manufacturer for rebuilding.
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EVWorld: Okay, I need a cup of coffee.
Josh G: That’s a lot to digest.
EVWorld: Too much cool stuff.