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GM Unveils Second Propulsion System for Chevrolet Volt: A Fuel Cell Variant

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Cutaway drawing of the Volt fuel cell variant. Click to enlarge.

At the Shanghai Auto Show, GM unveiled a second propulsion system for the Volt concept under the aegis of the E-Flex electric drive family: a hydrogen fuel cell variant that uses GM’s new fifth-generation fuel cell system as its primary power source.

This second variant of the E-Flex system combines the new 80 kW fuel cell stack with an 8 kWh (50 kW peak power) lithium-ion battery to provide up to 300 miles (483 km) of petroleum- and emissions-free electric driving. The Volt fuel cell variant is plug-in capable, adding up to 20 additional miles (34 km) of range each time it is charged.

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The two Volts, battery-dominant with ICE range extender on the left, fuel-cell centric on the right. Click to enlarge.

Unlike the first Volt propulsion system, which is battery-dominant with a small combustion engine range extender, the second system is fuel-cell centric, and uses a blended operating strategy to augment its range and power with a battery pack that is half the size of that in the first Volt.

A different configuration under E-Flex in which a smaller fuel cell would function as the range extender to a larger battery pack is also possible. (This is the approach Ford took with its HySeries concept. Earlier post.) However, this is not the design that GM implemented in the second variant of the Volt.

The E-Flex system is a flexible all-electric production vehicle architecture that can be configured to run on electricity from a number of sources.  It was first shown in January at the North American International Auto Show in the Chevrolet Volt concept vehicle. The first Volt concept is a plug-in series hybrid electric vehicle that has a 40 mile all electric range and uses a small bio-fuel engine with a generator to extend its range to 640 miles (1,030 km). (Earlier post.)

We think electrically driven vehicles are really going to be a big part of the solution to the energy and environmental challenges that our vehicles face.  We’re talking about purely electrically driven vehicles, not a hybrid, not mechanically driven.  And this really sets the stage for diverse energy sources in simpler vehicles.

When we talk about electrically driven vehicles, we're really talking about what GM calls E-flex.  It has a common drive architecture, electric drive component, and electric drive architecture.

The key is to be able to create and store electricity onboard the vehicle, and you can store electricity obviously by plugging the car in and storing electricity in a battery.  And you can create electricity by running an engine generator or by using a fuel cell.  So the key enabling technologies here are engines and generators and batteries and fuel cells and hydrogen storage and the plug in capability that they offer.  And then because electricity and hydrogen can be generated from a range of energy sources, we can have all that diversity with a very simple, common E-flex electric drive architecture, so that really helps from a business standpoint. 

—Larry Burns, GM Vice President Research & Development and Strategic Planning

The fuel cell variant shares many parts with the first version of the Volt, such as the front electric drive component.

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The 5th generation fuel cell system in the Volt. Click to enlarge.

GM’s fifth-generation fuel cell system is half the size of its predecessor, and provides the same power and performance. The fourth-generation system currently powers the Chevrolet Sequel concept vehicle. To double the specific output of the fourth-generation system, GM worked with different material sets and then improved efficiency and improved yield from each square inch of material inside the cells.

Our improvements are in management of all of those gasses and the water flows, [and] the selection of the materials to make that whole membrane electrode assembly center. It’s a system. The real key is in the controls.

—Larry Burns

The Sequel stores 8 kg of hydrogen and delivers a range of 300 miles (483 km). The fuel cell Volt—a lighter vehicle—will also deliver a range of 300 miles, but with only 4.0 kg of hydrogen (75 miles/kg) stored at 10,000 psi in two Type IV tanks.

The front drive motor offers a maximum 70 kW of power, with 250 Nm (184 lb-ft) of torque. The Volt fuel cell variant also showcases GM’s two third-generation wheel hub motors, packaged inside the rear wheels to add torque for all-wheel electric drive capability. The new motor technology reduces mass and produces more power (25 kw and 500 Nm /368 lb-ft per motor) compared to the first generation shown in 2003.

The fuel-cell Volt accelerates from 0 to 60 in 8 to 8.5 seconds, and has a burst top speed of 120 mph, with a continuous top speed of 100 mph.

A variety of other technological advancements and lightweight materials contribute to the efficiency of the Volt. With an estimated curb weight of 3,500 pounds (1,588 kg), it weighs 30% less than the Sequel. The fuel cell propulsion system is packaged entirely under the hood and is equivalent in size to a four-cylinder engine with automatic transmission.

The Volt also features molded GE plastic panels on the fenders, window glazings, instrument panel and steering wheel, which offer between 30% and 50% weight reduction per part. The car is fitted with low rolling resistance tires.

The global economy is going to grow 3% or 4% per year, and there’s a correlation with that economic growth to the demand for energy growing at about 2% per year. 

You know you compound 2% over 10 years, that’s 25%.  That puts you right in the range of the efficiency gains that you get from a hybrid, right in the range of what it would be energy efficient-wise versus a gas engine, and right in the range of what most people think can be teased out of the internal combustion engine going forward.  So we really need to look at alternatives in addition to just efficiency improvements to solve this problem.

So we really think now is the time to face the reality.  We have to find solutions to the energy and environmental challenges that automobiles face.  We have to do it in General Motors simply as a matter of business. If we don’t, there are real concerns about the growth of our industry being capped and that’s not a good thing for our industry.

And at General Motors, our strategy is pretty simple.  We want to displace petroleum, displace oil, reduce the amount of oil that’s being consumed, and we think the key to doing that is through energy diversity.  By having a wide variety of energy pathways made available for automobiles, we can grow our business and we have the chance of growing our business sustainably going forward.

We’ve become increasingly confident that we can meet the automotive competitive targets that we've set for the [hydrogen fuel cell] technology, $50 per kilowatt, 150,000-mile life, with a 300-mile range. But before this technology can be made widely available, governments, energy suppliers and infrastructure companies around the world need to collaborate with GM and the auto industry to develop a market for fuel cell vehicles and hydrogen fuel.

—Larry Burns

Comments

Roger Pham

Warren,
Your enthusiasm is admirable, but there are many things you haven't considered!
How do you get the 900lbs number? If you substitute the high-energy/low-specific power battery with a smaller high-specific power battery, your weight saving won't be that great, since high-specific power battery is inherently twice as heavy per wh. The 1.3kwh high-power battery of the Prius II capable of 21kw, or a 16C power factor, weighs as much as 40kg, or 32 wh/kg, whereas NiMh typically is rated at 65 wh/kg, and Li-ion has ~130 wh/kg. Where do you get the power/capacity factor of 44C? Pure fantasy! Most hobby NiMh or even Lipo batteries are rated at 10C-15C. The Prius' 16C is very good!

If you install marginal engine size that must be reved to the max everyday by leadfooted drivers, marginal batteries, fuel cell stacks, etc... how many miles will your "dream car" last? A few thousand miles may be?

A HEV's engine/drive train/battery must be designed to last beyond 150,000 miles. The higher the engine rpm typically required for a marginal engine size, the shorter the engine life, due to the extreme stress that aluminum con rods, piston, and steel crank shaft are undergoing. Metals can endure only so many cycles at a given stress-strain cycle before breakage. The higher the stress level, the fewer the number of cycles they will endure before catastrophic failure. Why do you suppose race car engines must be rebuilt after every race?

Ditto for batteries. The Prius battery is not charged beyond 70% and not discharged below 30% for durability reason. If you max out battery power with every acceleration, you can't warranty your battery for 100,000 miles to satisfy EPA regulation.

Ditto for fuel cell stacks.

Plus, a marginal engine size may do Okay for a cool day, but in the desert heat of 110 degrees, your engine power will drop may be to about 1/2, or if you have to climb hills in Colorado or Mexico City at 7,000 ft altitude, your puny engine won't take you anywhere. Ditto for frigid cold winters or areas where battery power and capacity will drop to 1/2.

Take home lesson here is do not design a "dream car" using the best possible or hyped-up numbers, ideal driving conditions or drivers, but consider the real-world numbers of performance of engines or motors, and real-world harsh weather condition, and real-world abusive leadfooted drivers...Motor generators of 95% efficiency are hyped up or peak efficiency only. Realworld numbers are between 80-90% efficiency, depending on cost of motor and load factor.

Warren Heath

Roger, I must admit, you finally almost got one right! I misread PEVE’s specs for the Metal Prismatic NiMH module which shows 1800 W/kg in the graph but 1800 W with some ambiguous Japanese character, which is for 1.51 kg so the actual Power/Energy is 28 for the modules, not 16C as your are claiming, and the link is:

http://www.peve.jp/e/hevkinzoku.html

This is certainly very good, and it shows what a real auto/battery company can do with the old technology NiMH batteries, instead of GM’s incessantly whining “The batteries are not ready, yet”.

Why do you keep fantasizing this “dream car” crap, maybe it’s your dream car, but it certainly isn’t mine. As I said, this is a hypothetical vehicle, that demonstrates conclusively that GM could easily put versions of the Volt on the road, as soon as they can be produced, and this is real “E-Flex” not propaganda E-Flex.

Your engine statements are way off the mark. The generator engine I proposed is a 34 hp or 25 kw rated diesel, which would produce the maximum continuous 18 kw for sustained speed of 80 mph. This is a typical derating for even Gensets that run 24/7. And boat motors like Yanmar diesels or Yacht series hybrid diesels, run much harder than the auto version – continuously at full output. So don’t even go there, it is not a problem whatsoever, powering an 80 mph Volt with a 34 hp diesel generator. And the generator / engine loading at peak (28 kw) can trivially be controlled to maintain engine life. Why do you desperately keep inventing these non-existent problems – just to help out the big Oil companies in their propaganda?

The Prius battery pack is 25% utilized because it is cycling every acceleration, and the life of a heavily cycled battery is greatly increased by using a low utilization factor. With a typical series hybrid battery in the 5 kwh range, the normal acceleration and hill climbing energy is easily contained in 1 kwh so the 25% cycling is no problem at all. And the 4 kwh balance is available for that very unusual trip through high mountains. The 2 kwh battery pack I proposed in this hypothetical vehicle is merely to demonstrate that an early production version of the Volt could easily be made using standard PEVE NiMH batteries, and would function quite adequately for the target, primarily city commuters market. And the efficiency of the vehicle would easily exceed the Prius’. Although personally I prefer the lower, cheaper power/energy ratio batteries, with a 5 kwh rating. But then GM will whine & cry that “the batteries aren’t ready yet”. While you never here them whine that “fuel cells are just not ready yet”.

The engine is not puny, it is actually oversized, due to the 80 mph continuous rating. Most driver’s don’t do that often, and standard city driving profile is 20 mph average. Which means the generator will be used at much less than full output, even at 60 mph, it will only be at < 36% of peak output and 40% of rated output. This is no problem whatsoever, Roger, and quite inventing trivial issues that are easily adjusted for, as they are in the Prius (except more easily due to the inherent flexibility of the series hybrid design).

Generators for Series Hybrids can easily be made 94% efficient, since the simple minded DC output allows for high, variable frequency multi-pole generators. Motors are more difficult, but the Tesla’s motor is average 90% efficient, although it is not an optimized design for efficiency and has an R&D funding that GM would consider coffee money. TM4’s wheel motors are 94% efficient @ 950 rpm & their generators are 96-98% efficient, of course you will claim that is all hype, but when GM shows off a car with an 80 kw fuel cell, @ $50 per kw, or any claim oil companies make, for you it is Gospel truth, even though I would have to pay $50,000 per kw for a fuel cell bought from a Real World, not GM fantasy world dealer. And I’m still waiting for that link on automotive PEM fuel cells peak power rating.

The <20% conversion losses in the series hybrid drivetrain are smaller than even the true drivetrain losses that your ICE or parallel hybrid will get under normal city driving conditions. And engine efficiency losses will double that. It’s quite understandable that the Prius took a big 25% hit in city driving under new EPA fuel economy standards, due to the inherent inefficiency of the parallel hybrid design.

You stated that “rigid cold winters or areas where battery power and capacity will drop to 1/2.” Actually a big problem with ICE vehicles and somewhat a problem for parallel hybrids (the Prius must run it’s oversized engine in cold temperatures to keep it warm – doing no useful work – like charging the battery). For a series hybrid, temperature control of the important battery pack is a no-brainer, easy to do, and maximum battery capacity is no problem. For your fuel cell on the other hand ……

Roger Pham

Warren,
PEVE spec's of 28C is a hyped up number so that they can sell the darn thing. Toyota is smart enough to not buy that, and derated the maximum power output of the Prius battery pack to 21kw, or 16C. Again, Warren, don't fall for hyped-up numbers from the internet, but do your own rigorous testing and testing of any hardware purchased and make your own real-world rating, if you wanna maintain reputation as a manufacturer. Look at what happened to the range of the Tesla, and the range of the Phoenix EV truck? Phoenix now has to scramble up a PHEV solution, just as I've mentioned this about their EV truck in GCC months ago. And you also know that GM just followed my advice about reducing the battery size from 16kwh to 8kwh, if you've read my original postings when the PHEV Volt just been announced in GCC.

You still haven't seen how ridiculous it is to install a genset of 18kw to a serial hybrid with a 2 kwh battery designed to carry 5 people, and expect it to hold up for over 100,000 miles just to satisfy EPA warranty requirement? This is for American market, Warren, not Yugoslavia (remember the Yugos?) or Kazakstan (seen the movie "Borat"?)

Serial-Parallel hybrid like the Prius is the most efficient HEV arrangement known at this time, with a tank-to-wheel efficiency of 37%. Serial hybrid is simpler but less efficient, for reason that I've told you many times before. If not, why do you suppose that Ford and Nissan licensed Toyota HSD technology? instead of scramble up a serial hybrid design like what you have in mind, huh,?

All cars will take a hit in mpg in the new EPA method of testing. The EPA numbers are just for comparison only, as they say "your mileage may vary". My Prius got consistently ~50mpg in combined driving over many tankful of gas. The official EPA number of combined mpg for the Prius currently is 55, so my number is not too far off. My 50mg number is a little bit lower than the EPA number because the car has to be started cold every morning and evening, thus wasting energy to heat up the engine with every cold start, whereas EPA may have done their testing all in one setting without cold starting their test vehicles many times over several days. I'll bet that if I would drive my Prius nonstop in the same combined city-hwy regimen as I do every day, I'll get the same 55 mpg combined number as the EPA. Of course, I'm a careful driver, whereas others who are not efficiency-concious won't get as much out of their Prius.

Warren, if you can manage to out-do the Prius using a serial hybrid setup, Ford, GM, DC, et al will have a prestigious "Engineer in chief" office reserved just for you. Just send in your application.

Warren Heath

Roger, buddy, I would say you should “do your own rigorous testing and testing of any hardware purchased and make your own real-world rating” of your own hydrogen economy, fuel cell way-in-the-future technologies. I guess you must believe GM could seriously make a Volt with an 80 kw fuel cell and $50 per kw with 150,000 mile life, as they claim.

Actually, Tesla’s temporary range reduction is common in the initial vehicle design process, and will easily be more than overcome with the introduction of higher energy and cheaper Li-Ion batteries. Already, Tesla’s 18650 format 2.2Ah cells could be replaced with the newer 2.9Ah or the newest 3.6 Ah cells, which would increase the range from the 200 miles to 327 miles.

As for Phoenix, I’ve always stated that BEV’s, series HEV’s, series PHEV’s, and even FCHEV’s are just options (remember E-Flex) of the standard EV chassis. So I was expecting Phoenix to come up with a series hybrid version of their EV chassis, and I expect Tesla will as well, when they can get enough cash. A simple problem for big bucks GM or Toyota, with engine technology on hand to achieve this, but much more difficult for small companies like Tesla, or Phoenix or Miles Automotive. Shows what pathetic losers (more likely corrupt bastards) GM is though, that tiny Phoenix is going to have a series hybrid on the road long before the GM all hype, no action Volt.

Actually, Roger, the series hybrid genset I described could easily be made much more reliable and long lived than your typical oversized ICE or parallel HEV engine. The generator engine would run at a steady rpm, no fast fuel gulping accelerations, no engine destroying idling. No unnecessary running at the 1-3 kw level that is typical in city driving. A half decent genset will run continuously for 5,000 hrs at full rpm with minimal maintenance, which translates to 360,000 miles for the 18 kw generator. And an automotive genset does not need to run at full rpm like the stationary genset in order to maintain 60 hz frequency. Good boat motors also have long lifespan at high output, much more severe service than the automotive genset.

The parallel hybrid or ICE vehicle will take a serious hit in fuel economy in City driving conditions (Prius from 60 to 48 mpg), because at the average 20 mph of city driving, the typical sedan uses 1-3 kw, when that energy must be provided by a humungous > 60 kw engine, efficiency will be greatly reduced, whereas the small high efficiency series hybrid engine can be run in the high efficiency zone for short periods to charge up the much larger battery – which means much higher efficiency in city driving. Note the Volt’s 50 mpg in spite of the greatly oversized 53 kw low efficiency generator burning E85, designed for 120 mph continuous highway speeds.

The main reason Toyota is using the parallel hybrid is that it is part of the secret settlement with Cobasys that they must have at least 50% gas engine drive. Why manufacturers still push H2, FCV’s, parallel mild hybrids, corn ethanol(oil ethanol) specials is due to the influence of Big Oil on their decision making. Oil is a multi-trillion dollar business and you are naïve if you believe that companies that can cause the world superpower to go to war, cannot control auto companies, at least to the extent of insuring that we can only buy vehicles that use their government subsidized petroleum products (why the huge subsidies for companies recording the largest profits in the history of corporations? – just a little suspicious don’t you think?). I don’t think Big Oil cares a whole lot about Phoenix, Miles, or Tesla because they will always be bit players in a trillion dollar industry, that requires capitalization in the billions of dollars level to produce a significant proportion of vehicles sold.

As for my “ prestigious "Engineer in chief" office reserved just for you” position, I would say you should be more interested in the 7 figure salary job waiting for you as senior executive in charge of disinformation at Chevron, assuming you’re not working towards that position already.

Oh, and I’m still waiting for that link on the peak hi power PEM automotive fuel cells.

Joe Simone

According to Joseph Romm, author of the "The Hype About Hydrogen: Fact And Fiction In The Race To Save The Climate", five technology miracles must be solved in order for the "hydrogen economy" to be realized:

  1. We have to solve the fuel cell problem
    • currently fuel cells are expensive and fragile
    • fuel cells for mobile applications (vehicles) must be able to withstand conditions of operating temperature range, vibration and humidity - repeatedly.
    • Current fuel cells (proton exchange membrane - PEM) can be easily poisoned by contaminants in impure H2
    • Major breakthroughs are needed.
  2. We have to solve the storage problem.

    See http://www.fuelcellstore.com/cgi-bin/fuelweb/view=NavPage/cat=1014

    • gaseous storage at 5,000 PSI or higher - volume penalty for storage container
    • liquid storage at -253 deg. C - volume is better but much energy is needed to liquefy.
    • stored as metal hydride. Weight penalty. Possible waste byproducts of conversion into and out of the hydride.
  3. Hydrogen’s quite expensive. There are no naturally occurring sources of H2.
    • H2 can be made from water, natural gas, coal, nuclear power, renewable sources etc. Each process has its own pros and cons.
    • can be generated remotely at a central location. Must be transported or piped to a local fueling station.
    • generated locally at the fueling station
    • generated on-board the vehicle
    Each generation/distribution method has associated with it concerns about efficiency, emissions, scalability and safety.
  4. Someone has to build all the hydrogen fueling stations. There exists the possibility of stranded investment if stations are built first and the transportation market moves to another technology and/or generation/distribution method. (ie H2 generated by wind power or photovoltaic arrays at home)
  5. For hydrogen cars to succeed, all other alternative fuel vehicles pretty much have to fail
    • pure battery electric vehicles (BEV) must fail to gain widespread acceptance
    • pluggable hybrid electric vehicles (PHEV) must fail to gain widespread acceptance
    • other, yet to be invented technologies must fail

According to Romm, hydrogen fueled vehicles will not play a *significant* role in reducing transportation sector green-house gases or dependency on oil in the first half of the 21st century (before 2050).

The book was written in 2004 and highly recommended for an insight into using hydrogen as a fuel. Given it is now 2007, some of the numbers may be out-of-date, but for the most part the book presents a fairly detailed view of "The Hype about Hydrogen".

SJC

"..it is part of the secret settlement with Cobasys that they must have at least 50% gas engine drive."

If it so secret, how do you know about it?

Warren Heath

Joe, you are on right on target. Besides Methanol is an excellent way to store H2 as a liquid, burns at 43% efficiency in an ICE engine or high efficiency in a Direct Methanol fuel cell, can be made for as little as $0.50 per gallon, and although it has 1/2 the energy density of diesel, it is environmentally friendly, burns more efficiently, and is much easier and more compact and safer to store than H2 or LNG or CNG or LPG.

SJC, all we have to go on is unofficial leaks, rumors and the meager information in Cobasys press releases. What do you expect, a signed statement from the head of Chevron, that they are deliberately trying to suppress the electric vehicle? Do you expect an official document from Exxon, giving Bush/Cheney a leveraged request to invade Iraq?

There are very curious terms in the released information. A quote from EVworld:
"....the specific terms are confidential, this stipulation in Panasonic's license restricting it to producing only "certain types" of NiMH batteries for "certain transportation applications" is widely interpreted and understood to mean that Panasonic can only produce HEV batteries (<10Ah) but not BEV batteries (>80Ah) for vehicles sold in North America until 2015... "

Roger Pham

Warren,
From all the assumptions that you've made about serial-parallel hybrid, I gather that you don't actually own a Prius. In mine, the engine only comes on when it first needed to be warmed up, and from then on, only when power over that which can be supplied by battery is needed by the electric motor. The engine never idles, but is only turned on to run at its most efficient regime when it's needed. Believe it or not, the Prius' engine can deliver near its peak thermal efficiency at only 1/5 of its maximum hp, or at about 15hp, as long as the throttle is nearly wide-open and the engine is lugged to the max at ~1300rpm or less. There is no need to run the engine up to 1/2 of its maximum rated power to get maximum efficiency. Of course, a lugged down engine cannot accelerate because its throttle is already almost wide-open, so, when acceleration is needed, the battery and the electric motor delivers a boost in order for the engine to accelerate to deliver more power for continual acceleration. When you ease on the gas, the throttle is not slammed shut on the Prius, but the engine continues to run efficiently to provide power to recharge the battery. In this way, the engine is never overstressed, nor run at low intake manifold pressure that results in inefficiency and increase exhaust emission. Kinda like the engine in a genset running at its most efficient regime all the time, EXCEPT that in the serial-parallel arrangement, the car is a mostly a serial hybrid in high acceleration mode, the engine revs up fast to give a lot of power to the generator which then sends high current to the electric motor running at low speed but high torque, simulating a transmission in low gear. At cruise, the engine in the Prius transfers >75% of its torque mechanically to the electric motor, thus preventing ohmic and eddy losses, and only <25% of power is transfer via the generator-motor route. The battery is constantly charged and discharged in respond to load requirement, while the engine is kept running as evenly loaded as possible. Even a slight uphill climb and the battery is discharged to boost torque, and even in slight downhill and the engine power is not cut but used to recharge the battery.

There is no need to use a puny engine at 34 hp rating to get the maximum efficiency as you've suggested. A 76hp engine for the Prius is about as small as would be practical in consideration of durability. Japanese-market car engines tend to be smaller than the US counterpart because people do not drive nearly as many miles in the cars' life span as here in the US.

My considerable experience with rechargeable battery in radio-controlled airplanes and cars have shown me that they are not as durable as IC engines. After 3-5 years shelf life and they are ready to be discarded, as performance dropped significantly. Batteries seldom maintain their maximum rating for long, and there is significant variation in capacity in cells. I hope A123 nanotech battery will change all that, but we shall see!

In the meantime, let's keep an open mind regarding fuelcell and the hydrogen economy. Progress are being made at breathtaking pace at reducing the cost of fuelcells and reducing the platinum required, or do away with platinum altogether. The latest Honda FCX is quite a remarkable achievement for FCV with respect to range, aesthetic, efficiency and utility. GM and Ford have no choice but to follow suit with the E-Volt FC-PHEV, and Ford with the Airstream and Edge FC-PHEV concept.

Warren Heath

Roger, your numbers just don’t add up. I would like to see BMEP/RPM/Efficiency curves for the Prius engine (please link this for me). Even a high efficiency TDI diesel, takes a 22% drop in efficiency at 1/6th rated power. And for EPA new fuel economy standards, the huge Prius engine has to run just to keep the catalytic converter warm in cold temperatures. Once again, it is desirable to have the smallest engine possible, which I have already proved to you will far outlast your giant Prius engine with it’s destructive idling, with a sufficiently large battery, that the engine can run near peak efficiency and proper operating temperature, for sufficient time to recharge the battery when necessary, very infrequently for a series hybrid in city driving profile.

The Prius should only use 2 kw average at the EPA 20 mph average City Driving profile. Even considering 40% losses for engine to generator to battery to motor and back in regen mode, that works out to 124 watt-hour per mile. Burned at 37% efficiency in a TDI diesel engine, which a series hybrid could certainly do, that yields 118 mpg, at EPA city driving profile. This is substantially more than the 48 mpg that the Prius gets. This is due to:
1) the oversized engine, which cannot supply the low power requirements, at city driving profile, efficiently
2) the undersized (low utilization) battery, which cannot store sufficient energy & power to supply normal acceleration and hill climbing loads, as well as allow the engine to run near peak efficiency for all energy supply requirements
3) the undersized electric drive, it seems only a meager 25 kw is actually available at any one time, which does not allow for capture of much of the braking or downhill energy
4) the complex drivetrain, synergy mechanism, which results in high percent losses at low speeds and fast accelerations

The Prius battery packs have been going strong for >7 yrs and 1 million kms. And the Rav4 BEV battery packs are still good @ 150,000 miles and > 5yrs. And this is old low R&D budget, NiMH batteries. If only batteries received 10% of the funding poured into fuel cells.

As I’ve stated before I’m quite gung-ho on fuel cells if done logically and sensibly. The logical, no payola, no corruption, no oil company crooked ulterior motives, path is:

1) Fast track development of the standard EV chassis for automobiles, including the batteries, first off for the series HEV (most short term economical), then the series PHEV, and then for the BEV
2) Simultaneously fast track development of high efficiency internal or external combustion engines and generators for series HEV’s. Develop economic production of simple to substitute liquid fuels like methanol, ethanol, biodiesel, and butanol, specifically to be burned in the standard series HEV generator engines.
3) Prioritize fuel cell development for stationary combined heat & power, fueled by natural gas or propane. The above mentioned battery development would also be useful in this regard. This would create a market for small, economical fuel cells of millions of units, much more revolutionary and economical than the vehicle fuel cell. This would also greatly increase the use of distributed energy production, mostly solar and wind. This high production volume would in turn drive and finance research into the vastly more difficult vehicle fuel cell.
4) When CHP fuel cells production ramps up sufficiently, if automotive fuel cells, using methanol fuel preferably (already would be available for series HEV’s high efficiency engines) can be made at a competitive cost, start installing them in vehicles. With the series HEV, already fully developed and marketed, the replacement of ICE generators with FC’s would be a triviality.
5) A gradual, modest research program into efficient, cost effective H2 production and storage could be maintained. This would have a much lower short term priority than points 1) to 4) above.

This method could save us from the approaching peak oil catastrophe. I just saw an excellent documentary, “The Oil Crash: A Crude Awakening”, that tells how not one person in a hundred, knows what is coming, and the flimflam going on in Oil, people buy their Detroit Specials, gas-guzzling behemoths, not realizing that they are not going to be able to afford to run them, when The Oil Crash comes.

Roger, going down the someday-way-in-the-future H2 dream, is going to guarantee that the Oil Crash will hit us so hard it will be brutal.

Check out: “ http://www.crudeawakening.org/ ”

Roger Pham

Warren,
Data for the Prius I engine is available in the discussion section part of the article "The argument for Hydrogen ICE" in GCC. Look for my discussion with yesplease. http://www.greencarcongress.com/2006/09/the_arguments_f.html#more

The Prius does not use the ICE to go at 20mph. Only the electric motor runs on battery at low speed or low power demand. Ideal for traffic jams, in which the engine is off the entire time, except to come on to run efficiently if the battery needs recharging. I can get 75-99 mpg on average at low speed on battery power alone, with the engine comes on only occasionally to recharge the battery. Get yourself a Prius, and try this, it's quite fascinating.

The Prius drive train is quite simple, with only a single planetary gear stage to coordinate the power distribution between the engine, motor, battery, and generator. The motor is 50kw size, plus an equivalent of 30kw of direct mechanical torque from the engine, to bring up a total of 80kw of available power. The generator is only needed to be 35kw size, since the battery is capable of 21kw for a total of 56kw of electrical power going into the 50kw motor, considering losses within the motor.

If you would have gone the serial hybrid route, you would need a 80kw motor, a 50kw engine as in the Prius, plus a 40kw battery and a 50kw generator to supply an equivalent amount of power to the wheel. Look at how much more copper and permanent magnets and battery material you are using, eh? Which one is more expensive? Gear? or copper, plus samatarum-cobalt magnet, plus Nimh or Lithium battery, eh? Toyota has answered that for you. The Camry Hybrid has an electric motor of only 40kw plus another stage of planetary gear to make up for a smaller motor than the Prius'. Gears are the cheapest.

Theory is good, but analyzing real life facts would be better.

Cheryl Ho

There are developments in DME in China today:
Since DME has an advantage of decomposition at lower temperature than methane and LPG, R&D for hydrogen source for fuel cell has been carried out.

If you would like to know more on the latest DME developments, join us at upcoming North Asia DME / Methanol conference in Beijing, 27-28 June 2007, St Regis Hotel. The conference covers key areas which include:


DME productivity can be much higher especially if
country energy policies makes an effort comparable to
that invested in increasing supply.
By:
National Development Reform Commission NDRC
Ministry of Energy for Mongolia

Production of DME/ Methanol through biomass
gasification could potentially be commercialized
By:
Shandong University completed Pilot plant in Jinan and
will be sharing their experience.

Advances in conversion technologies are readily
available and offer exciting potential of DME as a
chemical feedstock
By: Kogas, Lurgi and Haldor Topsoe

Available project finance supports the investments
that DME/ Methanol can play a large energy supply role
By: International Finance Corporation

For more information: www.iceorganiser.com

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