• Sep 6th 2008 at 10:19AM
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click above for more of Eberhard and his Tesla Roadster

By describing the cost to charge an electric vehicle as "squishy," Martin Eberhard begins a post on his Tesla Founders Blog on the right foot. Seriously. That's because it's a very difficult question to answer and it totally depends on where you live, what company your power is coming from and when you charge it. There are other factors too, such as what, if any, alternative sources you have and how much power you usually use on an average day. To help explain all of these little details, Eberhard has made a spreadsheet based on Northern California's rates from Pacific Gas and Electric.

After doing all the math, Martin figures that it costs him 3.6 cents per mile to run his Roadster. That's more than he initially figured but still just a small fraction of what it would cost to run on gas. For instance, at $4.00 a gallon, a car that gets over 40 miles per gallon would still cost double per mile to operate. Of course, YMMV. To help figure it all out, Martin suggests that you create your own spreadsheet and share it with the rest of the class.

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    • 1 Second Ago
      • 7 Years Ago
      The price anyone can calculate. $40k was a number I saw in the past. Tesla says (to magazines, can't find it on their site) and I believe there is a pro rated warranty for a usefull life 5 years/100K miles.

      I don't see Porsche or anyone else saying you will only get 5 years/100K out of an engine. I have been a car owner for over 20 years and I have owned a few cars over 10 years old with over 100K miles on them, all with the original engines, and I have never had to have an engine opened. My current car I bought new in 99. That engine barely makes the oil dirty between changes. It will outlast the rest of the car.

      Lithium Ions will degrade sitting in your driveway. Park it for 5 years and you battery will still be mostly toast.

      You can't claim the ICE wears out like batteries because it doesn't most will outast the car they are in these days.

      What I am saying applies to practically all EVs. Batteries costs per mile are higher than gas/mile by a significant amount. You can't look at just electricity/mile.

      You don't buy an EV to save money.
        • 7 Years Ago
        Lets not forget that there are no mass produced lithium batteries out there. Everything to this point is pretty much hand crafted. It doesn't seem reasonable to believe that in 4 or 5 years the batteries won't be much better and much cheaper. As soon as there are production cars to put them in, the cost for these batteries is going to drop dramatically.
        • 7 Years Ago
        Snowdog: Well, if you ever do find the article with that $40K quote, let us know.

        What I have never understood is why EV naysayers like you and tankd0g and rj and Kerry/Ken/Kent lurk around forums like... AutoblogGREEN, for crying out loud! Just where is the "green" in your autos?
        • 7 Years Ago
        I am not anti-EV. I am anti-BS.

        I think EVs are clearly the way forward, but batteries do remain a stumbling block. To do a cents/mile and exclude them is disingenuous at best.

        As far as battery prices. Why does a Volt with a third the battery capacity of the Tesla, cost $20K more than a Prius?? Batteries.

        My personal estimate is $1000/KWh. That is just a ballpark, but is actually low compared to the price for batteries with known prices in Hybrids like the Prius. Yeah different chemistry, but NiMh are usually cheaper than Li-Ions...

        $40K is not out of line for a Tesla pack. Phoenix is paying $65K for it's second batch of 35KWh packs, but they are advanced. Do you really think the Tesla packs is undercutting everyone else by 50% or more on battery packs. Look around. I challenge you to find a pack with a known price under $1000/KWh.

        At a $1000/KWh the Tesla pack would be $50K+.
        • 7 Years Ago
        Yanquetino, why the "if you aren't with us..." attitude? Must everyone be pulling hard on the EV bandwagon else they be labeled a blasphemer and stoned?

        These people all have valid points. Battery packs ARE expensive, they DO wear out and a modern ICE is really very maintenance free. The green in the ICE is that it will typically go 200,000+ miles with very little performance degradation and little more than fresh oil and filters.
      • 7 Years Ago

      As far as Tesla lying. Where have they ever said anything about battery pricing? I haven't seen anything about numbers from these guys. Maybe some 5 years in future guestimates, but there are no hard numbers. I am basing on other packs with known prices. Nothing is remotely close to $1000/KWh that I have seen.
        • 7 Years Ago
        And where did all those reporters get that $20,000 figure? From Martin Eberhard, who should be in a position to know!

        Hmm, that works out to about $380 per Kwh, quite a bit less than the $1K per Kwh that has been bandied about. Come to think of it, that's quite a bit less than the $1,500 per Kwh price for the NiMH batteries currently used in hybrids!

        No wonder Tesla is so optimistic on their Model S project!
        • 7 Years Ago
        PeterG: Ah, yes! Now I recall the Edmunds test-drive report. What finally jogged my memory was the caveat of using the electric heater:

        "In the real world of city driving with the temperature hovering around 40 degrees F and the electric heater humming away for comfort, we managed a little over 60 miles before it was back to Mitsubishi headquarters for a recharge."

        They must've had to push it back to the garage, d'you think?

        To reciprocate, here's what you requested:

        Newsweek: "The $20,000 battery pack is pricey, but it is generating so much interest, Tesla hopes to license it to major automakers." ( http://www.newsweek.com/id/55405/page/2)

        BusinessWeek: "The sophisticated energy storage device that sits in the trunk of the Tesla Roadster is merely a bundle of 6,831 laptop battery cells. Right now this pack costs about $20,000 to produce, about one-fifth of the car's price." ( http://www.businessweek.com/magazine/content/07_31/b4044419.htm)

        Mercury News' Silicon Beat: "[Mike] Harrigan [former VP, Customer Service & Support]: The expected battery life is 5 years or 100,000 miles. We consider the battery's end of life is when it reaches 80 percent of original capacity when recharged. The batteries are quite expensive. Today they cost $20,000. Over the next four or five years, we expect prices to come down substantially -- to the $12,000 range.” ( http://www.siliconbeat.com/entries/2006/08/18/the_tesla_roader_taken_for_a_spin_and_its_gutwrenching_vc_roadshow.html)

        Liar, liar, pants on fire, huh?
      • 7 Years Ago
      As Martin said on his blog, this article is NOT about total cost of ownership, it's about how much is paid 'at the pump' to move the car around. This is just PART of the TCO, not the whole equation.

      To bring into question things like cost of the vehicle, maintenance, shelf life of batteries, etc. just serves to confuse the issue at hand.
        • 7 Years Ago
        Actually, I'd say the exact opposite is true. Here you have a car that works on a very different system than an ICE. To put out an article about only the cost at the "pump" is misleading when the basic operating mechanics of the vehicle have essentially shifted part of that pump cost to other items, namely the battery.

        To make a more blatant example, I could write an article about a solar powered vehicle and expound on how it costs nothing to run, it's all free sunlight! Of course, such an article could conveniently gloss over other facts like the cost of the solar cells, replacement of the cells and problems driving at night. Sure, the solar car costs nothing to fuel, but so what? Its design has simply made other trade offs that shift the operating expenses elsewhere.
      • 7 Years Ago
      "$4.00 a gallon, a car that gets over 40 miles per gallon would still cost double per mile" 10 cents per mile is almost triple the price and when's the last time you saw a 40mpg roadster?
        • 7 Years Ago
        Not since the 80s....
      • 7 Years Ago
      Hmmm. He somehow forgot to amortize the $40000 battery pack in there.

      This is and always has been the Achilles heel of BEVs. Just about ever BEV on the planet actually costs more to run when you factor in the battery as the consumable that it is.
        • 7 Years Ago
        The price of the battery pack is part of the buying/selling price of the vehicle. .. it is not that the battery is worth 0 when you resell the car. So the extra costs for that battery are largely paid by what you get back for it when you change car, just like the extra investment you make for a hybrid comes back to you when you sell the car.. actually with the Prius you get almost always more than what it should be worth.
        So if you want to pout the price of the battery in the list, you should put the price of all elements in the list.. they all can break down before their expected lifespan is reached.
        • 7 Years Ago
        What is the lifetime of the battery pack, in your opinion?
        • 7 Years Ago
        The battery is unlikely to abruptly die, it is a case of slowly loosing capacity. After about 150,000 miles, battery capacity will have dropped to 80%, some might replace it at that point, others might wait several thousand more miles, or be fussy and replace it sooner.

        The current estimated battery cost is $22,000 but no one knows exactly what it will cost to replace years from now, as improvements may drive costs down, or inflation may drive costs up. Also, the battery may have some residual value, either as recyclable scrap or as a storage battery for utility load leveling.

        It's a bit difficult to predict exactly how long the battery would last, or how much it will cost to replace, and that makes any prediction of amortized costs very iffy.
      • 7 Years Ago
      Snowdog: NOT true. Show us the actually source of that $40,000 claim for the battery pack. We want to see the price quote.

      And show us side-by-side the total cost over, say, a ten-year period, driving 1000 miles-per-month, of comparable BEV and ICE vehicles which includes the "consumables" in the other column, i.e., not just $4-per-gallon gasoline, but also oil changes, filters, belts, antifreeze, hoses, transmission fluid, tune-ups, mufflers, etc.
        • 7 Years Ago
        Not to mention any number of expensive repairs that are commonly accepted as business as usual for the complicated ICE.
        • 7 Years Ago
        Yes, and make sure you include those things for the Tesla, which has a liquid cooling system, lubricants, tires, brake pads etc.
        • 7 Years Ago
        The cost of a Tesla over say, a Prius is more than $40k. If you don't include that in your figuring you might as well forget it.
      • 5 Years Ago
      I don't want to rain on everyone's green parade but where do you think your electricity comes from?

      According to the US Energy Information Administration stats for 2008 (no stats yet for 2009 or 2010) 48% of our electricity was generated by COAL fired plants and over 90% was generated by Coal, Oil, Gas, Wood and Nuclear power. Another 6 % is created by hydro-electric but those numbers are declining as California (probably the biggest environmental disaster this side of the Gulf of Mexico) continues to drain the mighty Colorado River to build McMansions further and further into the desert.

      So please, keep plugging in and thumbing your nose at the peasants who can't afford a Tesla but are doing no more damage than you are.
        • 5 Years Ago
        But you've conveniently overlooked the fact that the percentage of coal use was over 50%, coal use for electrical power is actually declining. The use of oil is insignificant, mainly for a few diesel powered "peaker" plants and emergency backup. Wood is also insignificant, mostly as cogeneration plants at lumbermills. The emissions from natural gas plants is low, and nuclear is even less.

        As for that California - Colorado river comment, it is non-sequitur. California is at the very end of the Colorado and any diversions of Colorado river water in California are below any hydro dams thus having no effect on hydroelectric production. But California does get about 20% of its electricity from hydro, and another 20% from other renewables (wind, solar, and geothermal). That renewable percentage is going up, not down. California gets only 20.1% of its electricity from coal. Plug-ins keep getting "greener" as more renewables and clean nuclear comes on line.

        But even in those areas where coal is the main source of power, switching from gassers to plug-ins can result in less emission. Fossil fueled power plants can use efficiency boosting devices too large for mobile use, thus achieve much higher efficiency than standard piston auto engines. Combine that higher efficiency with the very high efficiency of the distribution grid and the high efficiency of plug-in vehicles, and the result is less emissions. (it's easier to clean the emissions from a single powerplant than from millions of exhaust pipes, too) BTW, it does take electricity to run the refineries, and the amount of electricity needed to make a gallon of gasoline would drive a typical EV about 25 miles. Less gasoline use means less electricity used by refineries.
      • 7 Years Ago
      Has anyone discussed downsizing the battery pack of the Tesla? In Europe the Tesla costs about EUR 120,000 (incl. VAT). This is not a competitive price for a car that competes with a 911, a more luxerious and handy car (ever tried to get in a Tesla when the hardtop is in place?). So, if for the European market Tesla would put a smaller battery (we don't need 200 miles range in a continent where major cities are not further apart then 100 km) the price could probably be lowered to 90k, and the costs for retrofitting the battery pack can be lower. Too simple of a thought?
        • 7 Years Ago
        Downsizing the battery also downsizes the power available, so there goes the 0 to 60 time. Moreover, the battery only accounts for only 1/5 of the cost of the car, the carbon fiber body panels add much more to the cost.

        By using a more conventional construction but the same powertrain, Tesla could make a version that was heavier and slower accelerating, but a lot less expensive. Tesla has already announced plans for future $50,000 and $30.000 models.
      • 6 Years Ago
      This book will answer every question you have about electric cars, hybrid cars, bio fuels, it is awesome. www.themanhattanprojectof2009.com
      • 7 Years Ago
      nobody knows (a) how long batteries are really going to last or (b) what the replacement cost will be.

      manufacturers can make all the claims they want about 100,000 mile batteries, but we need to see it first. Tesla talking about $20k replacements on 100k batteries may or may not turn out to be true, but motor company estimates usually turn out to be wrong, and wrong in the wrong direction.
      • 7 Years Ago
      Tim is absolutely right: Martin's blog entry was an attempt to clarify the cost-per-mile to CHARGE a Tesla Roadster from the electric grid in his area of the country, and to invite others to calculate the same for their areas. He was NOT trying to determine how much it costs to OWN an EV --let alone assert that it is cheaper than owning an ICE.

      Yet the EV naysayers lurking in the dark corners immediately have to start waving their arms and yelling that Martin is obscuring the facts, that it is cheaper to invest in an ICE. Why? Because they desperately want to convince others to conclude: "Oh... well... let's just forget about EVs then and keep burning fossil fuels in our cars, since its cheaper in the long run. In fact, let's shut this forum down, we're obviously on the wrong track, having been duped by all the 'silly lies' in 'Who Killed the Electric Car?').

      Time and time again, I have found that anything the sockpuppets cite, any figures they calculate, any data they quote, are always either nebulous, bogus, or at the worst-case-scenario end of the scale. And even if those data were accurate, they conveniently skip over the reality that any emerging technology is always expensive at the outset. It is only over time, as production ramps up, that prices drop to levels affordable to the masses. Think of calculators, digital watches, laptop computers, LCD televisions, cell phones, i-Pods, and you'll get the picture. What those naysayers are claiming is that, because the first i-Pod cost so much, we would have been better off to keep buying and listening to portable CD-players instead. Right...! We should have also just kept 8-track stereos in our cars.

      But the biggest irony of all in this particular case is that the naysayers doom-and-gloom pronouncements are untrue.

      Let me give just one example using assumptions that --for argument's sake-- purposely err on the side of the naysayers. (I don't believe them for a second....)

      Let's look at the Mitsubishi i-MiEV that Kerry/Kent/Ken has lambasted in his customary rebuke.

      According to the earlier report here in ABG, the i-MiEV's projected cost, sans the initial Japanese subsidies, will be ~$37,000. Let's pretend that said price will never drop lower, even though the manufacturing will increase to 2,000 vehicles in 2009, 4,000 in 2010, 10,000 in 2011, and beyond. Let's say it will always cost $37,000. (Yeah, right....)

      The i-MiEV's battery pack weighs only 44% of the Tesla Roadster's ESS. It is not unreasonable to assume that less weight = less materials = less cost. Nor is it unreasonable to imagine that, since Mitsubishi and GS Yuasa have formed a joint venture to produce those batteries in-house, the price could be even lower. Nor is it unreasonable to think that, since GS Yuasa is now looking to manufacture those batteries here in the USA (see today's ABG report on this), the prices will drop even further still. But... let's project that the i-MiEV's battery pack will not cost less than 44% of the Tesla's pack. In fact, let's say it will cost 50%. As others have pointed out above, to replace the Tesla's ESS would cost ~$20,000, 50% of which would be $10,000. Now let's project that said price will never go down, it will remain as high as ever over time, despite the increase in manufacturing, or the factories in North America. (Sure....)

      Let's remember that the i-MiEV comes with that $10,000 battery pack as part of its $37,000 price. It is only when and if the pack is depleted that its replacement will add to the overall cost of the vehicle. As others have also pointed out above, lithium-based batteries are projected to propel an EV for 100,000 miles of peak performance. But let's say that you just wouldn't be content with, say, a mere 80% of power in the battery after that: you'd insist on replacing it with a brand new one. And let's also assume that future batteries won't get any better: 100,000 miles is all anyone could ever hope for. (Duh....)

      Now let's say that you drive that i-MiEV 300,000 miles. That's right: you have to replace the battery pack twice before you get rid of the car and buy a new one. And let's pretend that the naysayer's ICEs will indeed hold up just fine for 300,000 miles also, with nary a hiccup in their drivetrains. (Don't hold your breath....)

      Mileage costs? In my area of the country, it would cost $0.013015 (1.3 cents) per mile to charge an EV, including nighttime discounts, but also summer price hikes. Gasoline, on the other hand, is running $4.50 at the pump. However, let's pretend that both prices will hold steady in the future, i.e., gasoline will never cost more than $4.50 per gallon. (Right....)

      We'll also pretend that all the maintenance and repair costs are a wash on both sides of the equation: all those ICE tune-ups, oil changes, belts, mufflers, etc., won't cost
        • 7 Years Ago
        PeterG: Well... shut my mouth. Battery packs cost $1,000 per kWh??? Yow! That means that the 53 kWh pack in the Roadster costs... $53,000! Those suckers at Tesla have been lying to us through their teeth.

        Yeah, your parameters make the i-MiEV pale in comparison. If its battery costs $16,000, and if that cost never drops with either time or volume, and if the pack is shot after 100,000 miles, and if the vehicle's sticker price stays just as high, and if gasoline is $3.50/gallon, and if that price at the pump doesn't budge, and if ICEs hold up for all those miles, and if maintenance/repair costs are just as high for the EV as for ICEs, then after 300,000 miles a Honda Fit would cost... $20,000 less. And the Toyota Yaris... a whopping $26,000 less!

        Damn. I guess I should've kept my portable CD-player, after all. Ah, well... the planet was warmer during the Jurassic period, anyway.

        Listen, please post the reference to that article by the group that tested an i-MiEV and achieve only a 60 mile range. I have tried to keep up with reports of test-drives in it, but somehow I must have missed that one.

        • 7 Years Ago
        "...you can't generate gasoline on the roof of your house."

        Nor would I want you to!

        Nice rant Y
        • 7 Years Ago
        Why not compare more to a car in it's class like the Honda Fit. Even the fit is bigger/has more room. An element. Come on, that is mini SUV. The iMiev is more like a Kei car.

        Where are you that gas is $4.50 California is currently closer to $3.50.

        Also Find me a battery pack anywhere that is under $1000/KWh. At $1000/KWh. The iMiev pack is $16000. This also makes more sense given the initial pricing.

        Please run your numbers again with a Honda Fit (more apt competitor) $3.50 gas (current California prices) and $16K battery pack.

        Basically you bend over backward to make it look like you are trying to be fair, but you aren't. It starts with your obvious choice of much bigger cards with 2.4 L engines, when the Fit/yaris with 1.5 L engines make a lot more sense.

        Other factors are being taken for granted on the electric side, like the 100 mile range from the same size Pack the Volt says they will get 40 miles from. (testing a iMiev one group got 60miles) this also impacts pack life negatively as more deep discharges are needed to cover the same distance.
        • 7 Years Ago
        Honda Fit with $4 gas = ~$55K
        IMiev with $16K battery (and free electricity :-)) = ~$69K

        Amazing how a tweak here or there changes things dramatically.

      • 7 Years Ago
      How do we know the battery costs $40,000?


      We know the battery pack has about 6800 cells in it.
      The pack stores 53 kWh of electrical energy.
      We know each cell is rated at about 3.7 volts
      53,000 watt hrs / 6800 cells /3.7 volts = about 2.1 amp hour rated cells


      So we search the web for a battery that can meet these specs.
      Even when buying in units of 1000 or more these cells end up at $10 each and that is just the bare cells we have not soldered them together or put them in any sort of container.

      To get the price of the pack Down to $40,000 you've got to get the price per cell down to $5.88 each

        • 7 Years Ago
        Um, Tesla was buying wholesale direct from the manufacturer, not retail, so the price of the cells was about $3 each.
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