smart ev announced
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Super Member
Joined: Dec 2001
Posts: 672
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From: Northern California
MBs
MBWorld Fanatic!
Joined: Jan 2005
Posts: 2,848
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From: Orange County
2005 C Wagon (No snickering please!)
I like all manner of electric vehicles. The battery is the hang-up in this EV variant of the car. Whilst they say it is good for ten years, it only allows 1000 charges. Thats only three years of driving for most of us. The battery is really expensive too, so when factored in along with the electricty from the grid, the cost of operation is the same.
This car seems to mimic the performance of the GM EV-1.
The Diesel-Electric makes the most sense to me. Same propulsion as a modern train locomotive. An inverter and AC traction motors would allow light weight motors in each wheel position, eliminating the drive train. AC traction with a variable frequency drive system is simple, well understood throught the process control industry, and would make just a little noise so people can hear you coming.
I found that driving the GM EV-1 was a bit dangerous because people could not hear you at all.
Sounds like they are putting together a test fleet to gather actual operational data from ordinary folks. Good idea, especially if you need to motor about in central London. I'd rather take the tube unless I needed to transport something too heavy to carry on foot.
I don't see it for sale anytime soon. Pity. Everyone who brings an alternative to fossil fuel to market gets a invited to go hunting with the Vice President.
This car seems to mimic the performance of the GM EV-1.
The Diesel-Electric makes the most sense to me. Same propulsion as a modern train locomotive. An inverter and AC traction motors would allow light weight motors in each wheel position, eliminating the drive train. AC traction with a variable frequency drive system is simple, well understood throught the process control industry, and would make just a little noise so people can hear you coming.
I found that driving the GM EV-1 was a bit dangerous because people could not hear you at all.
Sounds like they are putting together a test fleet to gather actual operational data from ordinary folks. Good idea, especially if you need to motor about in central London. I'd rather take the tube unless I needed to transport something too heavy to carry on foot.
I don't see it for sale anytime soon. Pity. Everyone who brings an alternative to fossil fuel to market gets a invited to go hunting with the Vice President.
Thread Starter
Super Member
Joined: Dec 2001
Posts: 672
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From: Northern California
MBs
Good points.
The electric wheel hub motors you mention have the disadvantage that they increase the unsprung weight drastically. It might be better to keep a more conventional drive axle and stick the motor on the frame to keep the unsprung weight low. In the smart ev that's particulary easy since one just has to replace the combustion engine with the electric motor.
An interesting white paper was published recently on www.teslamotors.com where they compare the overall efficiency of various technologies, from well to wheel. They calculate how many kilometers one can drive per MegaJoule of energy. Here are some numbers:
gasoline combustion engine: 93 Honda CIVIC VX, 51 MPG EPA number
It can drive 0.52 kilometers per MJ.
gasoline hybrid electric vehicle: Toyota Prius, 55 MPG EPA combined
It can drive 0.56 kilometers per MJ.
Electric car: smart ev. Drives 100 kilometers with 12 kWh of energy
It can drive 1.05 kilometers per MJ.
Hydrogen fuel cell vehicle: F600 Hygenius, 100 kilometer per kg hydrogen
It can drive 0.70 kilometers per MJ.
Thus the electric vehicle wins this well-to-wheel energy efficiency comparo.
The electric wheel hub motors you mention have the disadvantage that they increase the unsprung weight drastically. It might be better to keep a more conventional drive axle and stick the motor on the frame to keep the unsprung weight low. In the smart ev that's particulary easy since one just has to replace the combustion engine with the electric motor.
An interesting white paper was published recently on www.teslamotors.com where they compare the overall efficiency of various technologies, from well to wheel. They calculate how many kilometers one can drive per MegaJoule of energy. Here are some numbers:
gasoline combustion engine: 93 Honda CIVIC VX, 51 MPG EPA number
It can drive 0.52 kilometers per MJ.
gasoline hybrid electric vehicle: Toyota Prius, 55 MPG EPA combined
It can drive 0.56 kilometers per MJ.
Electric car: smart ev. Drives 100 kilometers with 12 kWh of energy
It can drive 1.05 kilometers per MJ.
Hydrogen fuel cell vehicle: F600 Hygenius, 100 kilometer per kg hydrogen
It can drive 0.70 kilometers per MJ.
Thus the electric vehicle wins this well-to-wheel energy efficiency comparo.
