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Report: GM May Introduce Series-Hybrid Prototype

AutoWeek reports that General Motors may soon introduce a series-hybrid prototype as a step in its development path to future electric vehicles.

GM Vice Chairman Bob Lutz told AutoWeek in an interview that GM executives believe that electric vehicles are the future, and that the company’s work on fuel-cell vehicles may first be realized as a series hybrid. GM CEO Rick Wagoner will reveal “a new step” in GM’s alternative-fuel vehicle programs at the Los Angeles auto show this month.

A series hybrid could run primarily on electricity from lithium-ion batteries, with an engine as backup to replenish batteries, Lutz says. The backup engine could be a diesel or gasoline internal combustion engine. Backup energy also could come from a fuel cell.

Such a vehicle would require “a much smaller fuel cell stack” than a vehicle in which the fuel cell powers an electric engine, Lutz said. It would be less complex than a parallel hybrid system, which constantly shifts between an electric and gasoline engine to power a vehicle.

“Tom Stephens [group vice president of GM Powertrain], Rick Wagoner and I believe in the ultimate electrification of the automobile,” Lutz said...“We believe that’s where it’s going...what started as a fuel cell project is now an electric vehicle project.”

In September, Lutz wrote that GM was not putting all its eggs in the hydrogen basket, and was considering a variety of power sources for electric-drive vehicles, including plug-in hybrids. (Earlier post.)

Lutz expects rapid battery development over the next three to four years will provide more energy storage.

(A hat-tip to Patrick!)



What, GM are you joking? ... but you killed EV-1! GM, have you now quarreled with your friend (BIG OIL)?


Gm killed the ev because as a small scale short term project they always kill off the test cars. Its a beancounter/lawyeresque method they always try to follow with all TEST cars.

Gm has crushed tends of tousands of test cars of ell types the ev cars were only a tiny fraction of the cars gm crushes.

Sid Hoffman

Honda killed the Insight and the EV1, but that doesn't mean Honda doesn't care about FE and new technology. GM has to make money to stay alive and the EV1 was a huge money loser.


I don't think the Big 3 are to happy with Big Oil after they killed their SUV market. What better way to get back at Big Oil!

Rafael Seidl

By far the cheapest way to produce hydrogen is via steam reformation of natural gas. The oil majors all have substantial interests in gas fields. If anything, switching to hydrogen could hand Big Oil a larger share of the total automotive + fuels pie (iff fuel cell stacks come down in price).


When is this going to be available? Three or four years from now. Meanwhile, Toyota is going to be releasing E85 capable hybrids and extending the range of their hybrid lineup.

I realize that it takes a long time to turn the Titanic around, but I think GM's choice to avoid producing more fuel efficient vehicles will lead to their marginalization as an auto manufacturer.

The Anonymous Poster

Minor pedantic comment: Sid, Honda's EV was called the EV Plus, not EV-1.


I would like to add to the comment of Rafael that,
there are vast reserves of natural gas under some of the oceans.


This would augment models that will go into production in the next few years.

In the meantime, It would be to GM's advantage if they expanded their BAS system (and perhaps e-supercharger/turbo to downsize engines) to all their vehicles.


A 40mi BEV with a backup generator, IDEAL.

Make the generator easily removable, so you can swap out for a fuell cell or more batteries.


it is kinda intriguing that lutz is basically acting like the prius and civic hybrid are too complex (i.e. hard to build, maintain). They are proven commercial products in the second gen already. GM hasn't brought a first gen electric anything out.

Why would a series fuel cell have a smaller fuel stack? It still powers an electric engine


GMs had this tech for some time. They introduced it in the gen II ev1. They also played around with a series version using the very simple and highly efficient Williams micro-gas turbine generator. It runs on almost anything without modifications! Altairnano has solved the L-Ion battery problems. GM only has to put together existing components. A bi-directional plug-in will add grid stability and back-up power for our homes. To sell, it needs to look and be priced like what people are already buying. Build it and they will come. Don't kill it because it's too efficient.


Smaller fuel cell due to the following:

Currently, they try to size a fuel cell stack to take on the duties of direct power for the electrical motor it must be sized large enough for acceptable acceleration. If instead you have the fuel cell constantly trickle charge a battery pack you rely upon the battery pack to provide large boosts of power whenever acceleration is required and the fuel cell stack need only be designed large enough to constantly charge the batteries at an acceptable rate such that the average power takes into account acceleration and coasting.

Charles Di

Hybrid Tech supposedly already developed one of the compact Chevys with lithium technology to go 80 mph. Why isnt that being used...


This is good news if it actually leads to a product and isn't just a PR reaction to consumer awareness of what aught to be on the market by now. A series PHEV will be the ultimate flex-energy vehicle, primarily electric, but that electricity can be generated so many different ways, and the liquid fuel can be any number of fossil or bio based stocks, depending on the configuration of the storage tanks and engine. Not being locked in to one type of transportation energy will become increasingly valuable as the price of fossil fuels rise with the world's increasing demand.

Charles S

It's ok to defend GM concerning EV-1 on grounds of economics and test platforms. However, if one is to judge GM on basis of their production vehicle history, then I have to question if GM can really commit themselves to this project.

EVs, fuel-cells and hybrids aside, today's GM only half-heartedly dedicated its resources to low-margain segment such as compacts and subcompacts. GM's core audience would not be interested in another EV-1, and a Series-Hybrid SUV would probably meet the same fate as curret Escape Hybrid. GM may enter Tesla Motors territory but I can see that they would rather leave that to the Corvette. The only place left for such a project would be to target against a future Prius-PHEV model.

Not to say that GM can't do it, but I just cannot see GM as a company that is willing to commit itself to a long-term strategy like Toyota is committed to its hybrid project. It's not about who is more green or noble, but rather just the pattern I see with GM. Unless GM is truly committed to reinvent itself, otherwise, such announcement are just yet another test car that will never be made into production.

Mark R. W. Jr.

But the real question is, can GM deliver?


Gasp! This is important news!
The way I read it, GM is sort of announcing that they are moving away from fuel cells, in favor of PHEV.
How about a headline "GM kills the fuel cell vehicle"?
The second issue I read in this: GM thinks a series hybrid can compete with Toyota's series-parallel hybrid!
Is this the seed of another GM failure? Series-parallel hybrids are clearly more efficient (although somewhat more complex), than series hybrids.

Ron Fischer

A series hybrid Hummer with 4WD would not be laughed at by GM's core buyers, and might sell in fleet quantities to the US military.


Ron Fischer,
AM General builds the HMMWV and H2. GM just sells the civilian versions (H1, H2), though they do make the H3 at a GM factory. Where GM does come in is the Duramax (benefit of GM+Isuzu a few years back), and Allison transmissions. 2 mode hybrid system (w/DaimlerChrysler&BMW) might come in a beefier version for light-medium trucks (5-17 tons GVW), milspec, or civilian.

M McDonald

GM was my grandfather's auto co. Ford was my father's and Toyota is mine. GM's best chance is if Bill Gates buys the company and let's the young brains loose.
Otherwise ...


If you go back and look at GM's press releases and announcements for the last 5 years, I think you will find some bold statements that never actually occurred.


I have some doubt. A gasoline engine is more efficient at turning cranks than producing electricity. A series arrangement may not produce enough gas mileage to be competitive.


The series vs. parallel issue is an interesting one. The parallel configuration allows the IC engine to provide much of the power to the drive system "directly" (through drive shaft and gearing) with less energy conversion. It allows smaller batteries and smaller, less powerful motor-generators to be used, and is favored if the power-to-weight ratio and / or power-per-dollar figures for the IC engine are substantially better than for electric motor-generators and associated power electronics. But it is more complex, and requires an IC engine that can be throttled over a range of power levels and speeds. That limits efficiency.

The serial configuration requires more battery capacity and larger motors-generators, but is simpler and more naturally suited for use in a PHEV. Regardless of whether it uses a generator turned by an IC engine or a fuel cell as the charging source, the charging source can be a lot smaller, and can run at a single constant setting. That allows for better efficiency and durability.

Also, new silicon-carbide switches will soon be driving a technology trend toward more efficient, lighter, and less costly motor-generators and power modules. That favors the serial hybrid configuration.

Overall, I'd say that GM is making the right choice.


Good points Silverthorn. However, the right choice for series vs. parallel hybrids is probably also very dependent on the driving patterns. For short-distance person transportation the series approach seems to be more suited than the parallel approach. We could do most of our driving in an all electric mode and only occationally switch on the IC generator to extent the driving range. For long-distance cargo transportation the parallel approach seems to be preferred since most of the time the battery will be empty and in this 'driving mode' it is more efficient to use a full size IC engine directly rather than loosing energy on conversion.

Overall, I'd say that GM got a brilliant idea for saving on the very costly lithium batteries that will be needed for any durable EV concept.

PS. To be sure, it would be nice if GM sold their series hybrids with an option for a flex fuel generator.

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