Please create an account to participate in the Slashdot moderation system


Forgot your password?
Transportation Power Technology

Plug-in Hybrids May Not Go Mainstream, Toyota Says 519

mattnyc99 writes "Honda's challenger to the Prius — the Insight hybrid that we discussed so lividly a month ago — got its official unveiling today at the Paris auto show, with insiders confirming it would be cheaper than the world's most popular 'green' car while still hitting the same fuel-efficiency range. But the hybrid-electric showdown comes in the midst of a sudden rethink by Toyota about plug-in hybrids. Apparently all the recent hype — over the production version of the Chevy Volt, plus Chrysler's new electric trio and even the cool new Pininfarina EV also unveiled today — has execs from the world's number one automaker, and alt-fuel experts, questioning how many people will really buy electric cars, whether people will really charge them at night to keep the grid clear, whether batteries will make them too expensive and more. "
This discussion has been archived. No new comments can be posted.

Plug-in Hybrids May Not Go Mainstream, Toyota Says

Comments Filter:
  • Why so doubtful? (Score:3, Informative)

    by philspear ( 1142299 ) on Thursday October 02, 2008 @05:19PM (#25238783)

    These same american car companies seemed all too eager to give us bigger, less fuel efficient tanks while demand was high. Obviously, that was a fad that was unsustainable, but they kept churning them out. Here we have clear proof that people want more efficiency and at least to feel like they're driving green, yet car companies aren't convinced they should give us them? Why is that stopping them now? Surely they haven't learned their lesson to think long-term rather than "Everyone is buying this right now, if these trends continue forever, and they will, then WOO HOO!"

  • by Altus ( 1034 ) on Thursday October 02, 2008 @05:20PM (#25238789) Homepage

    Plug in hybrids still use gas. That's why they are hybrids, otherwise they would simply be electric cars.

    The idea here is to juice up the batteries at home and use them for the first x number of miles (hopefully enough to handle your commute). After that, when the batteries are low, a small diesel (or gas) engine will start up and begin charging the batteries providing you with more range. So if your out of juice you would simply fill up just like a regular car.

    Of course I'm curious how they will report the millage on these cars. I would want to know the range on the electric system and the millage when running purely on gas, but I worry they will come up with some new way to measure it that has little to no meaning.

  • by compumike ( 454538 ) on Thursday October 02, 2008 @05:25PM (#25238863) Homepage

    When fuel prices got too high, interest in electric vehicles and alternative energy sources boomed, but simultaneously demand weakened. Now oil prices have come off ~30% from their highs, and suddenly EVs are not a totally obvious solution anymore? Duh... this is how the market it supposed to work. This means that electric vehicle companies are going to have to start competing on real merits and not just squishy fuzzy green feelings. And I hope that makes them stronger! But it's not the worst thing in the world if conventional gas-burning cars remain an acceptable/affordable thing for the time being.

    Learn electronics! Powerful microcontroller kits for the digital generation. []

  • by MtViewGuy ( 197597 ) on Thursday October 02, 2008 @05:36PM (#25239023)

    ...there are serious issues with the pollution output from a diesel engine, even if you're using biodiesel fuel. Reducing the higher NOx gas output and the diesel particulates is a very expensive proposition, and just to make a diesel engine meet the EPA Tier 2 Bin 5 standard is expensive enough that you might as well buy a Toyota Prius or the new Honda Insight instead at pretty much the same price.

  • by TooMuchToDo ( 882796 ) on Thursday October 02, 2008 @05:37PM (#25239027)

    EVs don't compete on squishy green feelings. They compete on the fact that their maintenance costs are substantially less (no or small transmission; no ICE parts; motor, batteries, inverter are primary drivetrain components) and the cost to drive is around 2 cents/mile compared to 15 cents/mile for gasoline. The problem is that the playing field isn't level. Oil is subsidized in the US through heavy tax breaks to oil companies, and energy density in batteries is still low because not much R&D has been done (due to cheap oil).

  • Re:Time Based Charge (Score:5, Informative)

    by TooMuchToDo ( 882796 ) on Thursday October 02, 2008 @05:39PM (#25239059)

    I ordered an electric vehicle, and am building another one from scratch. To charge them, I built a charge controller that fetches the current price of power from my utility, and only charges the vehicles when the price of power is below a threshold. This way I take advantage of Time Of Day pricing (1-2 cents/kwH between midnight and 4am, Nuclear power in Northern Illinois).

  • Toyota may be right. (Score:4, Informative)

    by fahrbot-bot ( 874524 ) on Thursday October 02, 2008 @05:40PM (#25239079)
    The Chevy Volt uses an IC engine to recharge the battery when necessary - like all other hybrids (though Chevy calls it a "range extender"). Plugging it in overnight simply pre-charges it. I guess that's a bit cleaner, but that would really depend on your local power plant. I don't know if pre-charging the battery via the grid is cheaper than using petrol on the go -- if not, why bother.

    Calling the car an electric w/range extender, rather than simply hybrid (or series-hybrid) is marketing speak.

  • by SaDan ( 81097 ) on Thursday October 02, 2008 @05:41PM (#25239091) Homepage

    This functionality is already present in the Chevy Volt. It has a timer so you can plug it in to the wall socket when you park your car in the evening, and it can be programmed to charge the battery starting at midnight, etc.

  • by irenaeous ( 898337 ) on Thursday October 02, 2008 @05:42PM (#25239099) Journal

    The Volt is supposed to answer that issue by having a combustion engine as a backup -- it runs and generates electricity that is used to run the car. So, in theory, you should never be in the situation you describe. You would also just fill up at the next gas station.

  • by Locke2005 ( 849178 ) on Thursday October 02, 2008 @05:45PM (#25239155)
    You can also use inductive or capacitive charging. Just park the car over a "grid" on the floor of your garage, and you don't have to remember to plug the damn thing in! (You could do the same thing for your phone and MP3 player if you put it in the exact same place every night.) That being said, I'm convinced plug-in hybrid and not full-time electric is the way to go. I already own 2 hybrids, and I'm ready and willing to buy a plug-in hybrid just as soon as they make one available that I can afford. (I'm anxiously awaiting Aptera [] availability in my area.) Of course, few people will be buying new cars of any sort until we get off this economic roller-coaster we've been on lately.
  • Re:Time Based Charge (Score:5, Informative)

    by SaDan ( 81097 ) on Thursday October 02, 2008 @05:46PM (#25239175) Homepage

    The volt has a charge timer built into the car's charging system. Set the timer once, and plug the car in any time. It will start charging (and/or stop charging) when you specify.

  • by dpbsmith ( 263124 ) on Thursday October 02, 2008 @05:47PM (#25239181) Homepage

    Around the turn of the century, electric cars had a range of about forty miles... the same as the Chevy Volt. All the improvements in battery technology have been able to do no more than keep up with our expectations of automotive comfort and speed.

    Electric cars have, for a century, been waiting for the big breakthrough in battery technology that has yet to occur. The brilliance of the basic TRW design--the one they could never get U. S. carmakers interested in, the design that is fundamentally the same that Toyota uses in the Prius--is that it only relies on the battery as a short-term buffering device, a "torquer" as TRW called it, to make up the difference between the torque that can be provided by a little economical gas engine and the torque that's needed in normal driving.

    So, a Prius provides a very meaningful increase in fuel efficiency without demanding a battery made of unobtainium. The Prius battery in fact only stores about enough energy to drive the car for about a mile.

    Despite the possibility that Toyota is putting a spin on things, what they are saying makes sense. As hobbyists have confirmed, a Prius is virtually ready to be a plug-in hybrid, needing only a bigger battery. It would seemingly be so easy for Toyota to compete in the plug-in hybrid market that I have to believe they have sound reasons for skepticism.

    Another possibility is that Toyota has encountered some serious snags that they're not talking about in trying to produce a plug-in version of the Prius. Perhaps GM knows about these snags and has some trade-secret ways of overcoming them... or perhaps GM hasn't discovered them yet, or is ignoring them because the Volt isn't really intended to succeed and is just a very elaborate "image" ploy.

  • by afidel ( 530433 ) on Thursday October 02, 2008 @05:51PM (#25239223)
    Nah, unless you are completely flat like Florida the reverse flow water storage is significantly more efficient and cheaper than molten salt.
  • Re:What Morons (Score:2, Informative)

    by TemporalBeing ( 803363 ) <`bm_witness' `at' `'> on Thursday October 02, 2008 @05:58PM (#25239293) Homepage Journal

    If Toyota don't build an plug in hybrid, someone else will. Like it or not, electric cars are the future. The combustion engines are not going to go away any time soon, but as soon as EV's become mainstream (in the next 5 years I think), two car households will have one ICE and one EV.

    One has to wonder what Toyota is thinking. The RAV4 EV which they discontinued and even tried to have destroyed was a perfectly fine vehicle, and many are still running today. I wish they would just re-introduce that vehicle, perhaps with modern batteries.

    Funny thing is - they already do. Just not for the U.S. market. The Prius is a plug-in in the Asian markets; however, the EPA regulations and testing (since they couldn't get the MPG number to be consistent!) forced them to remove the capability for the U.S. market. Hopefully, the EPA will re-evaluate their position, else they'll be a thorn for everyone.

    Want proof: check out the guys behind the PriusPlus and all the aftermarket reverse engineering that has gone on - some of them even restored the functionality!

  • Re:Charging at night (Score:5, Informative)

    by compro01 ( 777531 ) on Thursday October 02, 2008 @06:08PM (#25239419)

    For any kind of sizable battery, you'd likely want a dedicated circuit anyway.

    The current Prius battery is about 1.5KWhrs, so assuming a dedicated 100-120V 15A circuit, it would take about an hour to charge from dead to full, but that will only get you a few miles on pure battery.

    The current plug in modification kit's battery is about 6KWhr, so 4x the time.

    Sources I see on the factory plug in say a capacity between 6 and 12KWhr, and a 12 would require a full 8 hours to charge, which is getting to the limit of "charge overnight", so you might want to put in a dedicated 240V 20A circuit, like you would use for an electric range.

    And you'd definitely need a dedicated circuit for a full EV, like the Tesla, as the battery pack is 53KWhr, which would take about 35 hours to charge on a dedicated normal circuit, and still 7.5 hours on a dedicated 220V plug.

  • by polar red ( 215081 ) on Thursday October 02, 2008 @06:10PM (#25239441)
  • by fred fleenblat ( 463628 ) on Thursday October 02, 2008 @06:18PM (#25239531) Homepage

    (replying to my own message)

    the wiki for compressed air cars says a prototype air-powered car did 7.22 km, or about 4.5 miles. that's much better than I thought, but still not practical for most commuters.

  • by superdave80 ( 1226592 ) on Thursday October 02, 2008 @06:40PM (#25239847)

    The Chevy Volt seems to be using two basic metrics.

    1. How far you can run on fully charge batteries (40 miles)
    2. MPG when the generator kicks in (50 MPG)

  • by Chris Burke ( 6130 ) on Thursday October 02, 2008 @06:43PM (#25239869) Homepage

    The Chevy Volt uses an IC engine to recharge the battery when necessary - like all other hybrids (though Chevy calls it a "range extender").

    Calling the car an electric w/range extender, rather than simply hybrid (or series-hybrid) is marketing speak.

    I don't think that's fair. In all other hybrids (on the market in the US today), the ICE is connected to the transmission and provides power to the wheels directly, in concert with the battery. They will use the battery and ICE proportionally to drive the car based on the speed. At highway speeds, they only use the ICE to drive and don't use the batteries at all. The range of most hybrids on pure electric power would be very small, and is really only the case when accelerating from a stop. On any normal daily commute of even a short distance, you're burning gas.

    The big difference in the volt, whether you call it "electric w/ range extender" or "series hybrid", is that the ICE is not connected to the drive train at all. It is nothing but a gas generator to recharge the battery. Thus why I think it's fair to call it an electric car, because the motor is in fact pure electric, and the fact that so long as the battery has sufficient charge, the ICE will not turn on at all. Also it has some big practical advantages. The ICE can be made smaller, and can be optimized for its task and made to operate at only at its ideal RPM -- the Prius' CVT means it can operate in a narrower band, but it still varies as it has to increase power to the wheels to accelerate.

    So I think it's fair to call it an EV. If you're only doing a short commute each day, then that's absolutely true, since the car will drive on nothing but electric power. If you need to go farther, the generator kicks in, extending your range. It's not just marketing, it's correctly emphasizing the real practical advantages that differentiate it from a normal hybrid.

    Oh, and in most places, yes it is cheaper to use electricity from the grid instead of gas. Especially if you charge during off-peak hours.

  • by bavid ( 842765 ) on Thursday October 02, 2008 @06:47PM (#25239939)

    Winds farms don't scale, and do affect the environment some.

    Gah. I wish that people would stop throwing around this FUD. There are plenty of studies out there, including one that I'm sure you've heard of [] that say relatively high wind penetration will work just fine. A lot of people like to recite the knee-jerk reaction that wind won't work, but I have yet to see much evidence that the sky is actually falling.

  • by Anonymous Coward on Thursday October 02, 2008 @06:54PM (#25240037)

    "The Chevy Volt uses an IC engine to recharge the battery when necessary - like all other hybrids"

    Woah, off from the start. Actually, most hybrids, including the Prius, can only power the cars locomotion via electricity at low speeds. The Volt, OTOH, uses electric motors to drive the car 100% of the time, whether your going 25 or 85.

    "Plugging it in overnight simply pre-charges it. I guess that's a bit cleaner, but that would really depend on your local power plant"

    Actually, it's cleaner even on a dirty coal-fired plant. The efficiency of the small engine in an automobile is very, very low compared to a centralized power plant. And since our power grid is not 100% dirty coal, that gives a plugged in vehicle an even greater edge.

    "I don't know if pre-charging the battery via the grid is cheaper than using petrol on the go -- if not, why bother. "

    It is.

    "Calling the car an electric w/range extender, rather than simply hybrid (or series-hybrid) is marketing speak."

    No - most hybrids, even theoretical plug-in hybrids, still REQUIRE the gas engine to run when traveling at high speeds. This means you still need to fill it up here and there (though less often than an all gas car, of course). With the Volt, however, you could buy it and never fill the tank. You then would have a limited range, but it'd be an option. The gas engine is there only so you can keep going after that 40 mile EV range - hence "range extender".

  • by superdave80 ( 1226592 ) on Thursday October 02, 2008 @07:06PM (#25240189)

    The 50 MPG is based on using only the gasoline generator without any energy input from the batteries.

    So, if you start up in the morning with completely dead batteries, you can still drive and get 50 MPG.

  • Re:Oh noes! (Score:3, Informative)

    by TooMuchToDo ( 882796 ) on Thursday October 02, 2008 @07:18PM (#25240317)

    Car dealer #3: Really? We can barely keep them on the lot []

    Prius sales fell 4 percent this year through August, a decline Toyota blames on insufficient inventory. ``We still have about a 48-hour supply of Prius and a pretty big waiting list,'' Lentz said.

    It's gotta be great as a car company when sales are going down because you can't make them fast enough

  • by CrimsonAvenger ( 580665 ) on Thursday October 02, 2008 @07:23PM (#25240365)

    The Chevy Volt is slated to be in the 35-40k range,

    So, for the price of this thing, I can buy a 25K sedan that gets 30 mpg, and run the sedan for 75000+ miles before I reach the cost of the Volt?

    Or, looking at it another way, using the same vehicle as a comparator, the Volt and the generic sedan break even on cost at about 187,500 miles. Not counting maintenance, of course, since we have yet no way to evaluate the cost of maintaining the Volt.

    Note: the above is for highway driving, not commuting. Strictly for commuting, the Volt will break even at somewhat over 75,000 miles, depending on the cost of electricity.

    I'll pass, thank you.

  • by HairyCanary ( 688865 ) on Thursday October 02, 2008 @07:26PM (#25240395)

    IIRC the important difference is that when a series hybrid like the Volt has sufficient battery power, it is 100% electric. Doesn't a Prius have to use the gas engine for freeway speeds regardless of battery charge?

    Electric w/range extender is perfectly valid terminology IMO, since plenty of people will see 100% electric usage. With a plug-in parallel hybrid like the Prius, what driving parameters have to be met to keep it electric only?

  • by pimpimpim ( 811140 ) on Thursday October 02, 2008 @07:26PM (#25240407)

    A nuclear plant gets about 20x10^9 kWh in a year, a windmill about 2-3 x10^6 kWh (a local windmill with >30m wings on has a real-time display of its performance over its lifetime). You will need about 7000 windmills to get the power of one nuclear plant. Where to put them? This is unfortunately not an easily avoidable environmental problem. You cannot put them too close, because that will decrease the efficiency (and change the influence of wind on local climates, be a danger to birds etc). You can not put them on all mountain hills because it kills the scenery (I personally don't mind, they are beautiful displays of engineering).

    Solar cells are maybe less of a problem to hide in the countryside, but their current efficiency is still way below power demanding applications.

    Geothermal is bad in so many ways, that I'd rather see it left unused. The chances on groundwater and even lower water depots contamination are too high (never underestimate the importance of safe drinking water), geologically risky (ground may move, with a very costly destabilizing effect on houses). And you can't have many per surface area.

    BTW based on the numbers from Tesla for the power need per kilometer including the loss at the loading station, a country like the Netherlands with 7 million cars averaging 15000 km/year, could have its electric need for car mobility completely covered by just one 20x10^9 kWh/year power plant.

  • by amliebsch ( 724858 ) on Thursday October 02, 2008 @07:31PM (#25240459) Journal
    A "plug-in hybrid" does have a gas engine for charging the batteries and energizing the motors, by definition. That's what makes it a "hybrid."
  • by mmontour ( 2208 ) <> on Thursday October 02, 2008 @07:32PM (#25240467)

    Um... have we managed to find a place to store nuclear waste? Have we uncovered an unlimited trove of radioactive material?

    Sort of. You start by re-using the "spent" fuel (with a combination of breeder reactors, and reactors like CANDU that don't require enrichment of the U-235). This greatly reduces the amount of waste that needs to be stored, and also reduces the need to dig for new uranium.

    For the radioactive waste that is left over, the storage place is "underground" (for example in old uranium mines). Or you can use the depleted-uranium trick of calling it "ammunition" instead of "radioactive waste", then disposing of it (at high velocity) in someone else's country.

  • by shmlco ( 594907 ) on Thursday October 02, 2008 @08:07PM (#25240775) Homepage

    "Of course I'm curious how they will report the millage on these cars."

    Most are reported as MPGE (miles per gallon equivalent). "MPGe is based on the quantity of heat energy that can be obtained by burning a US gallon of gasoline (115,000 BTUs). The equivalent in terms of another fuel is the amount of such other fuel that would produce that same amount of heat. That other fuel equivalent is then the unit that enables mileage per that unit. On this basis MPGe is a meaningful measurement." []

  • by AJWM ( 19027 ) on Thursday October 02, 2008 @08:22PM (#25240897) Homepage

    They should design hybrids so that the transmission switches the energy source. Higher gears switch to battery power, lower gears switch to gasoline.

    That's pretty much the opposite of what you want. Electric motors develop peak torque at low RPM, gas engines at high RPM. In fact I wonder about the losses in the additional transmission if you want to drive the wheels from the gas engine; mechanically it makes more sense to use the electric all the time (much simpler transmission) and run the gas engine at a constant speed (more efficient) to keep the batteries charged.

  • by Ungrounded Lightning ( 62228 ) on Thursday October 02, 2008 @08:23PM (#25240905) Journal

    Eventually, solar will work too, but since solar isn't reliable it will never be a primary power source until someone invents a magic battery.

    They already invented it. It's called the "vanadium redox flow battery". (Also a good match for wind power in single-mill residential applications. Added bonus: DC voltage conversion is free, simplifying peak power tracking controllers for wind and solar.)

    It's already being deployed in power-grid sized units, used as an alternative to local peaking-generation plants. (Charge during off-peak and discharge during peak. Cuts line losses, eliminates local noise and pollution, lets you power more locally than you have lines to supply during peak times, and moves power from cheap times to expensive times while losing less than the price difference to battery inefficiency.)

    Home-sized and electric-vehicle-sized units will probably be available when somebody decides there's a demand, licenses the patents, does a bit of product and manufacturing engineering, and starts supplying them. If something better doesn't come along first, that is. (The new fast-charge long-life lithium ion batteries, for example, might beat them, due to simplicity and high power-to-weight ratio for vehicle applications, followed by economy-of-scale price advantages once they're adopted for buses and autos.)

  • DOE study (Score:3, Informative)

    by shmlco ( 594907 ) on Thursday October 02, 2008 @08:40PM (#25241051) Homepage

    To quote, "A new study for the Department of Energy finds that "off-peak" electricity production and transmission capacity could fuel 84% of the country's 220 million vehicles if they were plug-in hybrid electrics. If all the cars and light trucks in the nation switched from oil to electrons, idle capacity in the existing electric power system could generate most of the electricity consumed by plug-in hybrid electric vehicles." []

  • by Ungrounded Lightning ( 62228 ) on Thursday October 02, 2008 @09:16PM (#25241317) Journal

    For everyone else, utility companies need to come up with a way to vary their rates generally according to load on the system - by introducing smarter metering systems.

    They already have them. They're deployed in many areas - where the economics of providing peak/offpeak rate differentials makes sense.

    At the moment providing such differentials in California does NOT make sense. Much of the electricity in California is used for moving large amounts of water around the state. There is enough water storage that this can be done only at offpeak times, and enough power used that doing it only at offpeak times can be used to level the power load. So that's what they do. Thus there isn't enough economic advantage from moving utility customer load to offpeak times to pay for a differential-billing infrastructure.

    A large deployment of plug-in cars - being plugged in after the evening commute at peak load time - might overwhelm this leveling. Or encouraging them as an antipollution measure might be politically advantageous. So once they're available you can expect the utility regulations to be modified to encourage electric cars - with separate, lower, rates for charging cars and offpeak-timing built into the new infrastructure. (Also: California utilities have a sliding-scale electric rate that drastically penalizes large residential electric consumers - with rates doubling or more for consumption sufficiently above a freeze-in-the-dark "baseline" rate. This will have to change for electric car recharging from residential power to be economically feasible.)

  • by fredmosby ( 545378 ) on Thursday October 02, 2008 @10:56PM (#25241841)
    Oil makes up an insignificant fraction of electricity generation. The last time I checked the breakdown for the U.S. was around: 50% Coal, 20% Nuclear, 20% Natural Gas, 10% Hydroelectric. Here [] is the wikipedia page on it.
  • Re:Um (Score:2, Informative)

    by amliebsch ( 724858 ) on Thursday October 02, 2008 @11:12PM (#25241909) Journal
    What are you talking about? You're all backwards. Please read this slowly: This story is about TOYOTA dissing PLUG-IN HYBRIDS - PLUG-IN HYBRIDS that *GM* is PUSHING. GM is pushing PLUG-IN HYBRIDS. PLUG-IN HYBRIDS are being pushed by GM. PLUG-IN HYBRIDS are being dismissed by TOYOTA. TOYOTA is dismissing PLUG-IN HYBRIDS.
  • by Derek Pomery ( 2028 ) on Thursday October 02, 2008 @11:27PM (#25241999)

    That article doesn't say wind farms scale, it just notes that multiple wind farms can take up the slack for each other.
    That article has a rather pathetic output for each one of these. 1.5MW of *peak* power which they are not producing all the time.

    A nuclear power plant will produce 2000MW.
    The average wind turbine according to Wikipedia, produces an average of 0.35MW.
    "Typical capacity factors are 20-40%, with values at the upper end of the range in particularly favourable sites. For example, a 1 megawatt turbine with a capacity factor of 35% will not produce 8,760 megawatt-hours in a year (1x24x365), but only 0.35x24x365 = 3,066 MWh, averaging to 0.35 MW." (thanks wikipedia)

    That means almost 6000 turbines(!) to match one nuclear power plant.

    I don't think the parent was questioning our capacity to distribute power, I think they were questioning the number of turbines we can reasonably fit without 'em taking over the landscape (wind power kills far more animals than nuclear power - think of the fuzzy bats).
    And, yeah, those turbines are *huge*.
    You can count the number of turbines that you can fit in a massive wind farm in the dozens.

    6000 turbines to equal one nuclear power plant. Dunno. I think that's what he was talking about.

  • Re:Um (Score:3, Informative)

    by philspear ( 1142299 ) on Friday October 03, 2008 @01:05AM (#25242485)

    Oh, yeah I did fail to read TFA. But you did say "'s GM that's saying Toyota is wrong..." which sounds like GM saying toyota is wrong.

    You're right though, GM does sound like finally they're getting up off their asses. They did take their sweet time though.

  • by sshore ( 50665 ) on Friday October 03, 2008 @01:11AM (#25242505)

    I too was excited to read about vanadium redox flow batteries []. For such a promising technology, it does seem to be poorly commercialized.

    It seems unlikely that we'll see this in mobile applications due to the low energy density. To quote wiki:

    Current production Vanadium redox batteries achieve an energy density of about 25 Wh/kg of electrolyte. More recent research at UNSW indicates that the use of precipitation inhibitors can increase the density to about 35 Wh/kg, with even higher densities made possible by controlling the electrolyte temperature. This energy density is quite low as compared to other rechargeable battery types, e.g. Lead-acid (30-40 Wh/kg) and Lithium Ion (80-200 Wh/kg).

    The main advantage of vanadium redox in mobile applications is quick fills, however certain types of lithium ion batteries also allow very fast charging with much better energy density.

    The flow batteries look promising for load-leveling of stationary alternative power sources. It would be interesting to see how they compare with lead-acid in $/Wh. I haven't found any figures on this.

  • by Aapje ( 237149 ) on Friday October 03, 2008 @06:47AM (#25243853) Journal

    That may be true, but the generic EPA standards are biased towards petrol. Petrol engines spew a lot of hydrocarbons, such as benzene. If the situation would be reversed, where 99% of americans are using diesel, petrol would have a hard time meeting the (diesel-based) emissions standard.

    In Europe, particulate filters will become mandatory for new car models in 2009 (Euro 5) and cars without may only be sold until 2011. The NOx limits will also be tightened, but will still be 2.5x higher than for petrol cars. In 2014+ (Euro 6) the NOx limit for diesel will almost be the same as for petrol. That limit is about halfway between Tier 2 Bin 8 and Tier 2 Bin 5. That should be achievable without urea, with a NOx catalyst.

    In the US, all diesel will be low sulfur in late 2010 (it's already mandatory in California). That will allow for low NOx cars such as the BlueTec to be sold everywhere.

New systems generate new problems.