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Automotive Hybrid Cars with the engine as the generator

  1. Jun 23, 2015 #1
    We know that electric motors are very powerful(hp and torque) and efficient than all the combustion engines. There are lots of advantages of electric motors to be used to propel vehicles as you can have the same maximum torque at any speed, very high pickup, high top speed as well as no need of transmissions . But when we consider electric cars, the biggest problem come up with the battery over the longer hourly time it takes to charge. So the best thing is the hybrid cars,( electric cars with range extenders.) Most hybrid cars manufactured today use a combination of the electric motor and combustion engine to power the wheels. There I think , encounters disadvantages as the combustion engine limits the performances of the electric motor. I think according to my knowledge, the best hybrids are the vehicles that are fully electrically powered with an engine or a fuel cell to generate electricity to charge the battery. But lots of car manufactures don't do that instead they use the traditional combination of fuel engine and electric motors. I need to figure out why they don't do so, because according to my knowledge, what I've speak of should be the best hybrid type in performance as well as efficiency. Can some one please explain!!!.
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  3. Jun 23, 2015 #2


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    Unfortunately, car manufacturers are limited to selecting real world solutions to the questions you pose.

    Hybrids use regular internal combustion engines because the infrastructure is there to support these types of prime movers, in terms of availability of fuel, mechanics who can service and repair the engine, etc.

    It's not clear what you mean when you say,

    You can't just pick out "an engine" to make a "fully electrically powered" car. You must have some practical way to generate the electricity which is used to either drive the car or to charge a battery, and car manufacturers have chosen the beast they know the best, the internal combustion engine.

    There are some experiments being carried out with cars being powered by fuel cells:


    The problem with fuel cells is that the fuel used is hydrogen, which is not widely available. Hydrogen must be made in a plant and then distributed over a wide area geographically in order to be a useful fuel for cars powered with fuel cells. There are a few experimental hydrogen fuel stations set up, but these are generally located in large urban areas. As of early 2014, there were only 10 hydrogen fueling stations in the entire US which were available for public use. Compare that tiny number with the number of retail outlets which sell gasoline or diesel fuel, and you'll see why hybrids have regular engines installed rather than fuel cells. :wink:
  4. Jun 23, 2015 #3
    Thank You for explaining. What I've actually meant is , a hybrid has a combustion engine. And it is fitted to a transmission box. And an electric motor too is used but both the engine and the electric motor is used to propel the vehicle. Instead of using the engine through a transmission box to power the wheels , what about removing the transmission box and instead, fitting an electricity generator and that generator charge the batteries. So that the vehicle is propelled by the electric motors, the engine act as the generator, which doesn't power up the wheels instead generate electricity to charge the battery. Isn't this system more efficient as well as more performance worthy as it misses all the lags of a piston engine? Plus weight and complexity is reduced as there is no transmission, and ride quality too improves. And I've further heard of fuel cells which uses ethanol.... Thank You.
    Last edited: Jun 23, 2015
  5. Jun 23, 2015 #4


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    Hybrid vehicles encompass a variety of different designs, not all of which use internal combustion engines.


    For example, so called "plug-in hybrids" can have their batteries charged using a special cable at a charging station. Of course, the charging stations may not be widely available.


    The limitation with using battery power only is that current battery technology allows only a limited range for a vehicle, and the charging time may be lengthy and inconvenient to people who are used to being able get into a car and drive at a moment's notice.

    Direct ethanol fuel cells are currently being experimented with, but practical implementation seems to be a bit far off yet. Ethanol as a fuel has few problems of its own, as people who use ethanol blended with gasoline can tell you.

    The point is, there are a number of competing designs for hybrid technology out there, and new technology is being developed all the time.

    What ultimately shakes out of this research and development is anyone's guess.

  6. Jun 23, 2015 #5

    jack action

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    My thoughts on this is that I agree with you that an «engine/generator» combo to recharge the batteries of an electric vehicle while driving is a better system than a «battery/electric-motor» pack added to an ICE vehicle.

    I think the choice for one technology over the other is a purely business risk analysis. If you have an ICE vehicle, it already sells well. You add the hybrid version, which may or may not sell as well. No matter what, the electric equipment usually have a low maintenance cost but the acquisition cost is always a lot more than ICE; and that is a very hard point to sell for typical consumer.

    If you design a pure electric vehicle and then add the hybrid version by adding an «ICE/generator», you are stuck with two versions of an electric vehicle that are hard to sell due to pricing (and if you can't sell the hybrid version, the non-hybrid version won't probably sell better).

    So in the end, I think the ICE version is still the «safety net» for most automobile company. At the moment, only high-end niche can risk a full electric version (i.e. Tesla). The mainstream companies that took that risk, don't seem to be very successful number-wise (Nissan Leaf, Mitsubishi i-MiEV). The Chevrolet Volt - which is the only «electric-hybrid» car as opposed to an «ICE-hybrid» and whose sales surpass its full electric competitors - doesn't seem to show financial success either. And that is with government incentives to help reduce the sale price.
  7. Jun 23, 2015 #6


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    Ib addutuion to what the others have said, you should look up the difference between a parallel and series hybrid
  8. Jun 25, 2015 #7
    Thank you all guys for explaining a lot of stuff. I recently(few months before) got to read an article about "Aluminum Ion Batteries", which are a lot cheaper, which has 7000 recharge cycles rather than a Li-Ion battery's 1000 and an amazing charging speed - { 100 times the charging speed of a Li-Ion battery} . The only drawback is that this Al-Ion battery has a capacity of 50% of a Li-Ion battery. But the experimenters have said they could improve the battery capacity more than that of a Li-Ion battery in near future. I think this going to be the ultimate practical solution for a more practical, fast charging , cheaper electric cars (even hybrids). A Tesla model p85D needs 8.5 hours to fully charge it's battery with a 240 domestic supply. If this car can be equipped with an Al-Ion battery of same capacity(predicting that the battery capacity is developed to the same amount of Li-Ion batteries) , it would only take 5-6 minutes:woot::woot::woot:. Think about that!!!:wink::wink::wink:. You just don't need supercharging stations. Any where with a domestic output is helpful. (110 supply will need double the time but still extremely quick):smile:
  9. Jun 25, 2015 #8


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    It isn't very clear to me what you are describing, but it sort of sounds like you want to make the car move with electric motors and charge with electric generators powered by those same motors, at the same time...which would violate conservation of energy. You need something adding energy to the system, whether it be a fuel cell or internal combusion engine.
  10. Jun 25, 2015 #9

    jack action

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    Have you read the quote you've put in your post? It sounds pretty clear to me that the use of an engine or fuel cell is part of the system described, especially knowing he already described it in the OP and that the title of the thread is «Hybrid Cars with the engine as the generator»:

    The question asked is the following:

    Why is the series-parallel hybrid configuration more popular than the series hybrid or electric-fuel cell hybrid configurations?

  11. Jun 26, 2015 #10
    It doesn't violate conservation of energy, I'm speaking of simply serial and fuel cell hybrids. I think serial hybrids are more efficient and more easy to repair and more performance worthy than parallel hybrids, because they don't have transmissions. Transmission box is heavy and complex which requires a greater effort and cost to repair and is expensive too mainly because they are heavy and complex. And it reduces the car performance. Although, new technology has reduced transmission issues greatly, more better to miss them in vehicles. So the serial hybrid system is the best solution for better vehicles. All these hybrid systems have come because of the issues of batteries. Today's batteries are still expensive, law in range and takes a longer time to charge. If a battery is made which can support a longer range in cars , cheaper as well as fast charging, hybrid systems are no longer relevant. Al-Ion batteries can be it . Still being developed, but cheaper and much faster charging than Li-Ion batteries. What do you guys know of Al-Ion batteries?.
  12. Jun 26, 2015 #11
    Electric cars are more costly because of the battery. The Li-Ion batteries are expensive . The other parts like the motors are cheaper than the piston engine and transmissions. Another reason for not showing a financial success because the battery needs a long time to charge , much longer than filling a fuel tank . So, the electric cars are mostly popular in traveling day to day short journeys. So those who travel long journeys often do not trend to buy electrics. These issues resulted in invention of hybrid technologies. Out of the 2 hybrid systems, the series and fuel cell hybrid types are more efficient and more performing. ( despite the buying price) . Fuel cells....how many types of fuel that can be used in fuel cells? What are the present issues of using fuel cells in cars? Do fuel cells are better in charging the car battery than the piston engine with generator? What about using a fuel cell with electric motors in a car without using a battery ( or using a law capacity 1 just to have a smooth ride, instant acceleration)? [Ex : Honda FCX Clarity]
  13. Jun 26, 2015 #12
    What about using micro turbines to power up the generator to produce electricity to charge the battery and supply electrical power to electric motors in demands? More efficient than piston engines nor fuel cells!
  14. Jun 27, 2015 #13


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    Jaguar built one:
    Though they canceled the project 2 years later.

    I can't find where the company that makes the turbines, Bladon Jets, has partnered with anyone yet.

    But the following article is interesting. Not just because of Bladon Jets wanting to implement your idea, but the whole factory concept looks interesting.

    I'm not sure if you are familiar with the pitfalls of huge companies like General Motors, but they can sometimes do very stupid things, IMHO.
    In 1996 they developed and leased an all electric car. 3 years later they canceled the program. If they had continued research, and developed an early hybrid, it's quite possible they would have been ahead of the game, and not had to file for bankruptcy in 2009. The Chevy Volt, introduced in 2010, is pretty impressive:
    I suppose if it had one of the Bladon gas turbines, it might have gotten even better mileage.
  15. Jun 27, 2015 #14


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    The market sets the design.
    A car can be made much much more fuel efficient but then it may be lacking some features such as acceleration, comfort, top speed, safety, headlights, passenger space, doors, reverse, a starter ( rather than a crank ), entertainment system, etc. Consumers want all that and manufactures sometimes do add in extra accessories for enticement. It usually is a balancing act to determine the wants of the consumer years ahead of actual production and hope that the needs do not change.
  16. Jun 27, 2015 #15


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    That's pretty funny, because it somewhat describes the fickle evolution of the cars I've owned.
    I went from zero option cars(poor young Om), to every option cars(great credit midlife Om), to a zero option car(options suck when they ALL break Om).
    But you are right, the market rules.
    I don't know what those little Bladon turbines cost, but I can imagine that they are an order of magnitude more expensive than the engine in a Volt.
    Since Leno, and a lot of people, seldom use their ICE's in their Volts, it really wouldn't make economic sense to progress to the turbine.

    But! I still like HyperTechno's idea. :smile:

    It might make more sense to develop a range extending trailer around this technology:

    These could be rented for extended trips. With a 30 gallon tank, and getting 40 mpg, you could drive halfway across the USA without having to fill up.
    hmmm.... I see HyperT is from Sri Lanka, length about 270 miles. HyperTechno, you can probably get by with a smaller gas tank. :smile:
  17. Jul 2, 2015 #16
    Hmmmmmm........:smile::wink:o0) :rolleyes: But micro turbines are cool aren't they?. There are news that Land Rover and Jaguar are going to pack micro turbines to their future hybrids(serial) to extend the range.( well they may going to make serial hybrids in the future). Micro turbines may be expensive than the ICE s but that's because they are not mass produced as ICEs. If they will be in the future, they(turbines)'ll be cheaper. It's a futuristic cool efficient replacement for the ICEs of serial hybrids. Any way. ........ . Do hydraulic hybrids require a ICE to operate the pump? Can't the pump be electrically operated?.............:wideeyed:
  18. Jul 5, 2015 #17


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    Using the Ford Fusion as an example, the ICE produces 105 kw of power, the battery's peak power is 35 kw, while the electric motor is 85 kw. Combined peak power is 140kw. The generator peak power is not stated. Apparently at most speeds, it's more efficient to have the ICE power the drivetrain in parallel with the electric motor than to use a larger, heavier, and more powerful generator and electric motor, except for standing start acceleration where it's my guess that the ICE drives the generator to drive the electric motor which can produce high torque at low rpm and low power, reducing the amount of high reduction ratio needed for the electronic continuously variable transmission.
    Last edited: Jul 7, 2015
  19. Jul 6, 2015 #18
    Using a small ICE generator at it's maximum continuous RPM reduces the fuel consumption than Using the engine to power the drivetrain....... Plus you really don't need a bigger larger engine to be used in serial hybrids. You need relatively a small ICE to run the generator than the size of the ICE you have to use in parallel hybrid to produce the same power!
  20. Jul 6, 2015 #19
    Can some what do a detailed comparison between a hydraulic hybrid and a pure electric car? About the power, efficiency, the space required by the systems plus the motors, smoothness of the powertrain acquisition cost and etc................:rolleyes:
  21. Jul 15, 2015 #20


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    A practical automobile must be able to deliver peak power well above cruising power, for freeway merges and passing. For peak efficiency, you'd size the internal combustion motor, the generator, and the electrical motor for cruising power - but then there's no peak power beyond that.

    You can oversize the electric motor and add a battery (you need the battery for regenerative braking in any case), use the battery to add power when the need exceeds the output of the internal combustion motor, but you still have an electric motor larger than optimum.

    Or you can arrange the drivetrain the way it's done in the Prius, so that the internal combustion motor and the electric motor can drive the wheels (with the electric motor drawing down the battery under peak power demand conditions). That lets you size the electric motor, the generator, and the internal combustion motor for maximum efficiency at cruise power but the power train is capable of twice that at peak.
  22. Jul 16, 2015 #21
    You mean that a parallel hybrid is more efficient and powerful than a serial hybrid? (in cases where both types uses ICEs)
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