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Toyota Unveils Plug-in Hybrid Prius

phlack writes "Toyota has announced a plug-in hybrid vehicle, based on their popular Prius. So far, it will only have a range of 8 miles on the battery (13km). They are going to test this vehicle on the public roads, apparently a first for the industry. From the article: 'Unlike earlier gasoline-electric hybrids, which run on a parallel system twinning battery power and a combustion engine, plug-in cars are designed to enable short trips powered entirely by the electric motor, using a battery that can be charged through an electric socket at home. Many environmental advocates see them as the best available technology to reduce gasoline consumption and global-warming greenhouse gas emissions, but engineers say battery technology is still insufficient to store enough energy for long-distance travel.'"

7 of 555 comments (clear)

  1. Re:Please explain by bluefoxlucid · · Score: 4, Informative

    The amount of energy stored per unit weight is considerably lower than that of an electrochemical battery (3-5 Wh/kg for an ultracapacitor compared to 30-40 Wh/kg for a battery). It is also only about 1/10,000th the volumetric energy density of gasoline.

  2. Re:Please explain by Copid · · Score: 4, Informative

    Others have answered fairly well, but it boils down to a few major things:

    1) It allows us to use locally-produced fossil fuels rather than foreign fossil fuels.
    2) Power plants are set up so they run at very high efficiency. Cars run at whatever efficiency they happen to be running at for the task they're doing.
    3) Probably most importantly, when cars stop using fossil fuel and start using electricity, they're able to use any sort of power source out there as long as it can be converted to electricity. As our central generators become greener, so do our cars. Automatically. Think of it like software: Why duplicate the "convert resources into usable energy" functionality when you can put it in a centralized place that can be upgraded without disturbing the rest of the system? Electric cars are the reusable code of the automotive world. Whatever your infrastructure, they can tap in to it as long as you can give them the electricity they need.

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  3. Re:Please explain by fyngyrz · · Score: 5, Informative
    The amount of energy stored per unit weight is considerably lower than that of an electrochemical battery (3-5 Wh/kg for an ultracapacitor compared to 30-40 Wh/kg for a battery).

    Exactly. So it may take quite a bit less than the ten years I specified; I was just being conservative. Thanks for pointing out that ultracaps are only one order of magnitude back now; a little while ago, it was two. And there are numerous technologies on the bench that show a lot of promise. We just have a tedious wait between lab pokery and commercialization.

    The gasoline energy density is irrelevant, of course; gasoline is used up and is non-renewable. Ultracaps aren't used up and are reusable millions of times (consequently, your car will wear out before they do.) Gasoline is energy, in a sense; ultracaps aren't - they're gas tanks. So you have to watch out for those kind of misleading comparisons.

    When you say that gasoline carries 10,000 times the volumetric energy of an ultracap, the reader may be misled into thinking that ultracaps can't deliver power. Not so. Designing an 1000 HP drive system that uses ultracaps is a matter of plugging a 250 HP motor onto each wheel, adding a controller and pressing the accelerator. Now you have a 1000 HP, non-polluting, sporty machine. Designing an 1000 HP drive system that uses gasoline means you are going to need your own mechanic, you're going to be producing one heck of a lot of pollution, and the cost will make the electric vehicle look positively thrifty.

    The best way to think of ultracaps today is that they are like gas tanks; they hold energy electric motors can use, just like batteries do. They're too small of a "tank" (today) to compete with batteries. A decent metaphor is the walls of the tank are too thick and the volume where the energy is stored is too small. And because they're made in small quantities, they are expensive. But they are improving rapidly and they don't use particularly exotic materials, so there is every reason to think they'll be good enough and inexpensive enough to replace batteries very shortly.

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  4. Here you go... by tinrobot · · Score: 4, Informative

    How Much CO2 Do Electric Cars Produce?
     
    ...Given the same assumptions about electric vehicles as in the American analysis above, electric cars in Canada could expect on average to cause CO2 emissions of 0.2*1.1*236 = 52 g/km to 0..3*1.1*236 = 78 g/km, compared to ICE emissions of 167 to 224 g/km.

    http://www.paulchefurka.ca/Electric%20Cars%20and%2 0CO2.html

  5. Re:8 miles? by Christopher+Thomas · · Score: 4, Informative

    This is wrong. Sort of. Lithium-ion batteries can power a car for 200 to 250 miles, but they're expensive.

    They do that by cheating. The Tesla, for example, carries half a tonne of batteries, and the car itself is built to be as light as possible (the batteries probably outweigh everything else put together, without passengers in it). Lithium batteries also tend to have lifetime issues; numbers I've heard quoted off-the-cuff for lithium batteries are losing 50% of their capacity within a year or two, and only being good for 100ish charge cycles, though this will vary with the specific battery model. This is tolerable for a cell phone or notebook, as you tend to upgrade these frequently and new batteries cost much less than a new unit, but a car will have serious problems under these conditions.

    For a battery-powered car to be really competitive, we'd need a battery technology with at least 5 times the storage density per unit mass, that was good for a decade of daily use before needing replacement. This may or may not be possible; time will tell (unless the engineering difficulties with fuel cells are solved first). On one hand, we aren't anywhere near the theoretical limits to the energy density of batteries, but on the other hand, people have been working on the problem for centuries.

  6. Re:some data on that please? by rossifer · · Score: 4, Informative

    If you're burning fossil fuels to make the electricity, which do you think is more efficient: a car which turns chemical energy directly into kinetic energy, or a car which starts by converting that same fuel first to electricty at the power plant, then transmitting it many miles, then converting it to chemical energy in the battery, then converting that back to electricity, and then using that electricity to produce kinetic energy?
    It's amazing that gasoline engines are so ridiculously inefficient, but the powerplant to EV "well to wheel" path is more efficient than the ICE vehicle (don't forget the distribution costs of gasoline, which are higher than for power plants). The "power plant to EV" path also substantially reduces carbon and nitrogen emissions (though usually increases the sulfur emissions when coal is in the mix).

    Here's a well-cited "paper" on the subject. Even if you don't trust the author to be objective (since his business is selling electric car kits), the references are unimpeachable and the numbers impressive.

    I'm all for reducing pollution, but if electric cars are running off the power grid, aren't they _worse_ than gas cars?
    No. They seem to be much better.

    Regards,
    Ross
  7. Re:Please explain by smilindog2000 · · Score: 5, Informative

    Burning fossil fuels at a power plant, charging your car batteries, and running all electric is from 25-100% more efficient. This directly reduces green-house gases. Also, with the added flexibility to choose what kind of fuel we use, we could pretty much eliminate foreign oil imports. Toyota is spreading FUD. 8 miles? What a crock. All Toyota has to do is offer this product. Plug-in hybrids are a great technology that can save money, reduce oil imports, and reduce green-house gases.

    BTW, every time I point out these simple sites and concepts that any dolt can easily understand, I get mod-ed down by a strange group that seems to read articles late. I have two theories on this: there are paid /.-ers who are paid to bury this kind of info; angry anti-environment /.-ers read articles late.

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