Wednesday, February 13, 2008

Electric Cars in US and Israel

Last Wednesday (which is my regular car day) I talked about the Tesla Roadster, a tiny $98,000 electric two-seater sports car offering considerable performance which certainly is not for everyone. This week I was hoping to talk about more mainstream cars which are in the works, but frankly my research left me quite depressed. (Though there is interesting news from Israel at the end of this post.) Right now I think diesels offer the best environmental solution, and hope to compare these with hybrids next Wednesday.

First, the good news. While Tesla decided to start with a niche car, they do plan additional offerings. To quote the company’s web site, “Our next model will leverage the Tesla Roadster‘s technology, resulting in a less expensive sports sedan that we can sell at higher volume.” (In other words my money will be subsidizing these cars, but no matter!)

By contrast, the two major US car companies have shown only concept cars. General Motors showed the Concept Chevrolet Volt at the recent Detroit Auto Show. GM is calling it an electric car but in fact the car’s “E-Flex” drive system makes it a plug-in hybrid. (Plug-in hybrids are hybrids which you plug in to the electricity supply, typically overnight, so that a typical commute can be achieved without using the gasoline engine. Aftermarket conversions are available for the Prius and other hybrids.) But rather than drive the wheels directly as in current hybrids, the Volt’s internal combustion engine is used just to charge the battery. Which means no extra power boost is available for acceleration, and therefore -- all else being equal -- one needs a more powerful electric motor. This seems a backward step to me, though I suppose running the engine at a constant efficient speed might be an advantage.

Currently the Volt is just a concept car, but GM claims it will build a production car just as soon as the battery technology is available, which they say will be in 2010. I find this hard to swallow, as they are expecting a range of only 40 miles on the batteries which I would have thought was readily available now. I have also not heard anything about performance. There is a lot of hype here, but basically GM is not planning anything that aftermarket amateurs aren’t doing right now.

Ford is a little more adventurous with what they call "HySeries Drive." This is another plug-in hybrid drivetrain but with a hydrogen fuel cell to charge the battery instead of a gasoline engine. Ford claim only 25 miles on the initial full charge, plus 200 miles from the fuel cell. In the absence of hydrogen stations, this would seem to be a problem. The vehicle, a modified Ford Edge, is also pathetically slow, with a top speed of only 85 mph.

It is hard to see the point of combining a fuel cell with grid-charged batteries. Neither electricity nor hydrogen is an energy source; rather they are ways of storing energy in a moving vehicle. Either batteries are the best way to do this, or hydrogen is. They can’t both be. Batteries may be necessary for short-term storage of the energy recovered from braking, but these could be very small and certainly not big enough to warrant charging from the grid. Alternatively, a capacitor or flywheel could be used instead (see my February 5th post) though of course you need a battery to run electrical equipment anyway.

It is hard to avoid the conclusion that both Ford and GM are playing to the gallery, though maybe they are making serious strides towards solving the problem behind the scenes.

Range is clearly a problem at the moment for electric cars. 40 miles may be OK for a typical commute, but every now and again everyone needs to make a longer trip. I would see these cars being practical only for multi-car households where one car would have to be a more conventional one like a diesel or hybrid. (See next Wednesday’s post.)

However, the main obstacle to universal adoption of electric cars is not so much the range but the time it takes to recharge them, typically about 5 hours. Again, this is OK if you can do it overnight prior to your daily commute, but not so convenient if you are on a trip. (I guess it could make for a more relaxed attitude to touring; do 40 miles, find a hotel, and see the sights while you fill up.) This is why the following recent announcement from Israel is so interesting.

Renault-Nissan, the government of Israel, and an electric charging station start-up called Project Better Place have announced a plan to make electric cars part of ordinary life in Israel in the next decade. Project Better Place will build stations where attendants will swap out depleted batteries and put in fully charged ones, saving the several hours typically required to charge a lithium-ion battery pack. Renault-Nissan plans to start shipping electric cars to the country in three years or so and I assume these will be especially designed to make battery replacement quick and easy. The cars will run on batteries being developed under a deal between Renault-Nissan and NEC, but they claim only about 45 mile range in the city and 72 on the highway. Even with fast battery changes, this would seem to be limiting, but the concept of changing the batteries rather than charging them does seem brilliant.

For full announcement see

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