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How Plug-In Hybrid Cars Could Be Game Changers

Over the last few months I’ve started thinking about buying a new car. My present car is 7 years old and problems are starting to creep up. New noises appear everyday and my dash lights appear to be failing one after the other. After 120,000 miles, I’m beginning to wonder if its time to get rid of the beast.

Considering my field of interest, I’m thinking its time to get a plug-in or an electric car. I’m thinking a new Chevy Volt or a Nissan Leaf will go well with our second car, a Toyota Prius. I would have considered the Tesla Roadster, but the lack of a backseat is a showstopper.  And there is that little problem that it has one extra zero in the price, which I’m told is not a typo!

Considering my 70-mile daily commute and my present car’s 25-mpg gas mileage, the change should give me some green cred.

All the planets appear to be lining up. Cars with my favorite technology are coming to the market. There is (up to) $7,500 tax credit from the Feds and $5,000 more from my home state of California when you buy these cars. You have a chance at getting the coveted carpool stickers (which are priceless!). Finally, we just bought a home, so “plugging in” is not an issue anymore.

The Leaf

Considering the $10,000 price differential between the Leaf and the Volt ($32,000 for the Leaf vs. $42,000 for the Volt, before taxes), I started paying more attention to the Leaf. With the two tax credits, this car was beginning to look like something that was highly affordable.

But a quick Google search and 10 minutes later, it was obvious that the Leaf was not going to work for me. When you see reports that you could end up with 47-50 mile range (under certain commute conditions) before you spend the next 8-20 hours charging the battery, you begin to realize that you get what you pay for. With a daily commute of 70 miles in traffic, with some days stretching to 100 miles, I will need to charge at work and, as of today, there appear to be very, very few charging stations available.

I heard this week that, apparently, a typical American takes 8 long trips (greater than 100 miles) a year. Our cars need to have the energy to take us on these trips.  The Leaf will have difficulty in being anything but a second or third car.

Clearly, at least for me, the low range and the long charging time were going to be issues.  Moving on…

The Volt

The Volt gets us away from the issue of range because it is a Plug-in hybrid (PHEV). With the gas engine as a backup waiting for the battery to run out of juice, you can have your cake and eat it too. Be green for the first 35 miles and forget the range anxiety on longer trips.

But at $33,000 for the car ($42,000 base plus CA tax minus the tax credits), this is still one expensive car. The EPA tells us that once you run out of juice, the car is rated as at 37 mpg. So my daily commute of 70 miles would consist of the first 35 miles on the battery and the next 35 miles on gas.

Without nitpicking, I would use 1 gallon of gas a day. This costs me, as of today, $4.

I also need to charge the battery (12.9 kWh) at 12 cents a kWh, which means I will spend an additional $1.55 for the electricity.

Total cost $5.55 per day. Right now I spend $11.20 a day. I will save about $1,400 every year when using the Volt.

My Subaru cost me $21,000 to buy. With this yearly savings I should get cost parity in … around 8-9 years. This does not include any of the time-value-of-money calculations, which would push this out more.

I’m sort of throwing numbers here without seriously checking into them, but suffice to say, it’s not an inexpensive car.

Beyond Economics

But it’s not all about economics, is it? Being green has never been cheap (Although the corollary does not hold. Meaning, if you are cheap, you can actually pass that off as being green!).

The first blog post I made on This Week in Batteries concluded that I could not afford the Volt.  Gas prices were at $3 at that time. At $4 the Volt still not inexpensive, but it’s getting to the point where one can start to think about this.

The future is uncertain (unless you are the Wall street-type and can pretend that drawing a trend line on past data to predict future price is worth $1 million a year in compensation!) and we don’t know where gas prices are headed.  But there are a few things we can conclude.

First, at present-day battery prices and energy densities, EVs don’t make much sense economically.  They are too limiting in range for use as a primary (or even a secondary car). If you get the range up by packing in more batteries it gets more expensive and you lose a bunch of trunk space to fit the batteries. I would say that we need to triple the energy density of batteries and cut the price by a factor of 4 before we can get serious about this (but you can argue with me on this one).

Second, a plug-in hybrid makes a lot of sense, but you will need to pay for the dual power sources. If you can cut the battery costs by a factor of 2 and maintain the tax credits, the concept becomes economical.

I heard that, apparently, gas consumption would reduce by 70-80 percent if we convert all cars to PHEVs. I, for one, would ask if we even need to work on a pure battery electric vehicle. Maybe the focus of all our efforts should be on getting a PHEV on the road at an economical price.

Irrespective of your views of how the world should operate, I think it is important for us to understand whether or not batteries can actually be made any better.  I shall use this as a launching point to talk about a few issues over the next few months including why we all use lithium batteries today, and what I think will happen to battery energy densities over the next few years. I also think its important for us to appreciate what the theoretical limits are in batteries so that we can temper our expectations.

In the meantime, I’m starting to think about test-driving the Volt. But the dealership tells me that I have to put a deposit down to test drive the car. Maybe I’ll pretend to be a journalist working for GigaOm to see if that gets me anywhere!

Venkat Srinivasan is a Staff Scientist at Lawrence Berkeley National Lab and writes about batteries on his site This Week In Batteries.

Image courtesy of Nissan, GM.

33 Responses to “How Plug-In Hybrid Cars Could Be Game Changers”

  1. Matt B.

    For people wavering on whether to buy a Leaf today or wait a year, 6%/year gain in battery capacity sounds small, but multiply it out and you get 3x gain in 20 years and 10x gain in 40 years. A Leaf-like car would go from 70 mile range to 210 and then 700 miles as the decades ticked by.

    It’s not clear that adoption could happen a lot faster anyway. New power plants, upgraded transmission lines, millions of garages upgraded for charging, extra battery manufacturing capacity and even increased lithium mining are all needed, and will cost a lot of money and time to get built.

  2. The author has a ridiculously long commute and then concludes that a pure EV can’t work for most people. The fact is that a 70 mile one way commute is not a sustainable way to live. The only reason people have come to accept that as a reasonable daily drive is because of a century of cheap abundant oil, which no longer exists. I agree that an EV probably can’t work for him in his present situation, but that’s a far cry from saying it can’t work for most people or that batteries need 4 time the density of current cells for EV’s to be successful. How about building a car that’s twice as efficient and gets twice the range from existing cells, such as the Solectria Sunrise which got over 200 miles in normal driving and 370 mile when hypermiling from a 26kwh pack of NiMH cells 15 years ago?
    Even the LEAF has room for more cells as it exists without losing cargo space, the cells just need to be cheaper. Tesla’s Model S will have 300 mile range and more room than a Volt, do batteries really need to be 4 times as dense so we can have 1600 mile range? Of course not, they just need to be cheaper so you don’t have to pay $80K for a 300 mile car, and the vehicles need to be more efficient so we can go farther with fewer batteries.

  3. Maybe it isn’t time to buy electric yet–at last for most of us. In ten years, the technology may mature and offer better choices, When new technologies come out the gate, they usually cost more then a few years later there are more choices, which means competition, and the prices go lower.

    It happened with computers and TVs.

  4. Hi Venkat, I have been following your blog way before you joined forces with GigaOM. I am all for minimizing pollution in vehicles, (I don’t say zero pollution since that is just a myth). I like your writing style too. This morning, I ran into this piece of news which talks about swapping batteries at charging stations instead of actually charging.

    I think swapping batteries makes more sense than waiting to get them charged. The technology to swap shouldn’t be hard to figure out, and it takes far less time than charging. I do agree that this might mean standardizing batteries shape and size, but its a good trade off for convenience. I would like to hear your comments on this.

  5. i get so tired of pontificators declaring the electric car is not worth the money. you guys never seem aware there are many brands of cheap electric cars, at least since the 1974 oil embargo. lithium batts give over 100 mile range to any lightweight car, can be way cheaper than a LEAF. can be as low as 2 cents/ mile in lightest weight e-cars.

  6. Nicholas

    Why do we need our cars to be capable of the eight total long trips we’ll take during the year? What’s wrong with renting, flying or taking the train? With the money you’d save on gas alone these options should be quite affordable. You are the exception to the rule, one of the very few who may max out the Leaf (a first-gen electric car) during one day. Most people won’t have this problem and will save thousands of dollars and tons of CO2 by choosing the leaf.

  7. David Martin

    The chief saving in pure electric vehicles will come in maintenance savings due to their inherent simplicity, and down the road after folk have got used to them in their lower depreciation.
    These savings are not available for hybrid vehicles, which are more, not less, complex than regular cars.
    If you depreciate the battery against petrol and add on electricity cost, then break even for an EV based on this without taking into account reduced maintenance and depreciation comes with petrol at around $4.60 based on the costs for Renault’s battery lease.
    To reach an equivalent for the US where leasing is not available take off around $5-7,000 from the cost to allow for it’s offset against petrol bills.
    When you do come to replace the battery pack in perhaps 8 years then at the present rate of decrease you might have to pay half as much for your new pack as now.
    Electric cars basically last until the bottom drops out, so you would then start saving on replacement vehicle costs.

    Hybrids may be more flexible than pure battery cars, but the economics for the latter are much better, as long as the range is enough for the job.

  8. Venkat Srinivasan

    Folks- Thanks all for the comments and apologies if I cant respond to each.

    Its interesting to see the various views of the Volt vs the leaf. The demographic here is probably not very representative of the wider population but its interesting to see the pro-electrification stance here.

    I think we can all agree (or maybe that too optimistic :-)) that we can get mainstream electrification only if battery costs come down. Now this is US specific. If you think the rest of the world, its even worse. The question then is: How do we make a cheaper battery. One way to do that is to make a more energy-dense battery and then decrease the $/kWh. This really is the challenge. If we can change the trajectory of battery energy density improvements from the ~6% a year to something higher (much higher?), then we can, all things being equal, reduce costs. And we can also have some trunk space!

    A lot of people are under the impression that this will happen. I have my point of view on this, but that is not for public consumption. Instead, I think its important for all of us to understand what makes a battery tick and how we can make a better battery. Only if we understand this can be understand if the promise of a better battery is possible.

    I want to use this post as a means of talking about these issues. So stay tuned…

  9. BreathontheWind

    While I have enjoyed some of your other articles I think you lost your logical thread here. You started off with an atypical set of parameters. !/2 way through the article you admit that they are atypical yet you conclude that “at present-day battery prices and energy densities, EVs don’t make much sense economically.” when you have not tested this against any data but your atypical situation. Saddly your conclusion is therefore not supported.

    Within its operating parameters the Leaf in California can be purchased for a base price of only $11,000 and at $4 / gallon petrol you would need the equivilent of a ($4/$.13/mile = ) 31 mpg vehicle just to match it in fuel costs (not counting oil, filter changes and by amortizing the cost of the battery over the warranty period. see my analysis here: ) But that is not the end of the story. Any vehicle that has an ICE, including hybrids, will require oil changes. These are as potentially polluting to the Earth as emissions: Then factor in the likelyhood of increased maintenance on a far more complex hybrid vehicle and you may agree with the experience of two car families where one is an EV. The EV becomes the primary vehicle of choice for every trip within its operating parameters.
    Excessively long commutes and trips to Grandma’s would be relagated to the second choice vehicle with the ICE engine.

    • Venkat Srinivasan

      I think a car with a 100 mile range is too limiting as a primary car. Some would argue that its limiting as a secondary car (but that is a point of view that needs to change, and fast!). If you agree with that, then the question you have to ask is: How do you make the leaf the primary car. I think you do that by making it go 200-300 miles on a charge under ALL driving conditions. This means a much bigger battery. Depending on your point of view, as much as a 4-5x larger battery. This adds 4-5x the cost. And it adds so much volume that you need a more energy dense battery. Hence my conclusion that they don’t make economic sense.
      If you think that a 100 mile EV can be a primary vehicle, then I think you may be willing to drive a atypical car!

  10. Douglas Quine

    The Honda Civic Hybrid and the Toyota Prius (as you know) both offer excellent MPG at a much lower price than the Volt. I’ve achieved 50 mpg in my Honda Civic Hybrid over 90,000 miles. Another approach is the new generation diesels (VW Jetta) which can also achieve similar results when driven carefully. There is no reason to settle for 25 – 35 mpg nor to pay $35,000+.

  11. Bruce Becker

    We’ve had a LEAF for about 800 miles so far. What you say about having a LEAF as a primary car are true. Although, I have driven the car to a 35 mile destination on 80 % charge and have had no trouble returning home. The key is that I travelled the city streets and had no problem. What I think most non-LEAF owners are unaware is that how you drive makes all the difference. If I travel the freeways at 65+ mph. a 70 mile round trip would need 100% charging with the LEAF.
    We do not like the idea of traveling with the ICE plus the EV apparatus which adds weight. We are happy with the range. I’ve found that driving the LEAF is fun in that it is somewhat like a video game. I found myself when we first had the LEAF that I was at about 3.5 miles per kWh. I now am at 5.0 mile per kWh and as of yet have had no other drivers “flipping me off” for driving at 60 mph in a 65 mph freeway. All the rest of the speed limits I drive at those or even a couple of mph above. I hope the Volt does well because that will bring all the more pressure on charging stations being available. Good luck on your choice, but I could see the LEAF meeting your commuting demands.

  12. Venkat, count me as a fan. Not only do I learn a lot about batteries from your pieces, but your clear-headed back-of-the-envelope economics calculations are a breath of fresh air (all the LBNL folks I know have this admirable skill). That, plus lines like “which I’m told is not a typo” make me look forward to your next installment.

  13. Stephen

    Have you run the numbers on a mix of bicycling and public transport instead of driving? It’s likely to be a lot cheaper and when you factor in your extra life expectancy it will probably take the least time. Bay area public transport is excellect.

  14. Volt Owner

    Venkat, with the climate in CA you should do better on your charge. I am in TX and get a pretty consistent 38-40 on the charge at highway speeds and 42-44 at suburban speeds. Fuel mileage I get 40+. Surely LLNL will let you plug in during the day and you’ll be driving 80% or better oil free.

    The whole test drive thing is outrageous. GM supplied dealers with 600 Volts that are only for test drives (the dealers are not allowed to sell them for six months and have to log the names of people who drive the cars). So that it total bunk. There are lots of people who you can find on the GM-Volt site ready to give you a free test drive and help you find a dealer that will not ask for a deposit to drive the car, will not gouge you on the price, and can get you the car you want in a timely manner.

    It is a great car. You gotta drive it to see.

  15. John M is right. The Leaf really requires most people to own a second car for those not infrequent longer trips. I wouldn’t be able to make a day trip to see my brother with a Leaf because he’s 65 miles away and there wouldn’t be enough time to recharge before the return trip.

    It’s both way less expensive and way greener to own one Volt than two cars (Leaf and something gas or diesel powered).

  16. I’m a huge fan of the volt, but hate the price, oh well, like you said, “Green isn’t cheap”

    I hear people talk about the leaf, and having it as a second car? WTF, how does this figure in being cheaper than just the volt?

    Chevy should do some serious marketing around that argument, i.e. If you own the leaf, you HAVE TO HAVE A SECOND car. I’m not sure I know any American that doesn’t drive more than 100 miles at least once a year.

    If we can bail out the banks, why can’t I get a 40K volt “loan” to save us from Foreign Oil?

  17. Venkat, glad to see you here adding your wisdom to a blog that more people will be interested in from a practical perspective!

    There must be something illegal about requiring a deposit to test drive a vehicle… somebody should take them to court.

  18. You can test drive my Volt all you want here in Santa Monica. But be careful of what you wish for. Most who drive this car have to have it. :)


  19. Richard Grahman

    A follow-up: We installed solar power (a ground installation) three years ago and have not paid for electricity since that time (just a meter fee!). We have had the Volt for three months and have not exceeded our power generation so we are very happy with this set up. We charge the Volt from 2:00 AM until around 6:00AM. It usually only takes 3 1/2 hours to charge on our 220 charger.
    We are saving over $250 per month on gasoline.

  20. Richard Grahman

    I think that you will find that the Volt is more than just a PHEV. It is built like a Cadillac (our other car) and is an unbelievable driving experience. We have 2500 miles on our Volt #324 and have used exactly 15 gallons of gasoline. We are retired and no longer commute but we make several trips of over 120 miles each month so many trips use some gasoline.
    This is a car that must be driven to fully appreciate.

  21. I run two electric as the first and second cars in our family. I have a ZipCar card in my wallet if I need more. After 38,000 all-electric miles I’d say that you can do it if your commute is more normal than 70 miles each way. You’ll need to choose a Volt or be able to charge at work.

    What you also need to factor in is the upgrade in refinement and all of the time you get back when you loose the maintenance headaches of a traditional car. Sadly, there isn’t a $ value for that but, after recently driving a gas car with all the din from up-front and the herky-jerky transmission I have to say that, if that’s what you need to get more than 100 miles on a charge – it’s a compromise too far for my lifestyle!

    Try the Volt, you’ll forget the extra expense when you drive it off the lot.

  22. Volt Owner

    Dr. HelklkkjlabkbjlkjhgkjhgkjhgkjhgjkYou will do much better than 35 miles on your charge unless you drive high speed , in CA you will probably average more like 40-43. You gas mileage on the care will come in closer to 40 (I am getting 42). Check out the gm-volt site and I know you will find LOTS of volt owners happy to give you a free test drive and to find a good dealer who will not ask for a deposit before letting you drive one. The real-world volt is a great car and the owners are finding that it exceeds the promises made by GM.

  23. As a person who’s spent a decade working to put PHEVs on the map, I’m delighted with your headline. I agree and appreciate your way of thinking about all this. As you say, your first take on this is an approximation, and since my family became the first household anywhere to have both a Volt and a Leaf, I’d argue that there’s a case for your going either way. Here are a couple of points, roughly following the sequence of your posting, that argue for one or the other:
    * Looking at the Leaf, why do you have to make that your “first” car. Why can’t the Prius handle all your extended range driving? The Leaf is a great second car for most two-car households.
    * If you use the Leaf, in your case, you will need to charge at work, but that’s becoming available, and with all the resources going into charging stations in the Bay Area, I’d be amazed if Lawrence National Labs wouldn’t be one of the first to make that available to its employees. And you could probably even get away with 8 hours of 120 charging to top off your electric tank.
    * You’re right that the Volt eliminates the range problem. You should be aware for your calculations that the Volt is NOT eligible for the $5,000 state credit: to get this car on the road on schedule, GM had to use a conventional engine that doesn’t meet the highest emission standards.
    * Your assumption you’ll spend 12 cents/kWh for electricity doesn’t allow for the possibility you’ll choose a separate meter for your car and pay about half that for off-peak plug-in charging.
    * When you said “But it’s not all about economics,” I was expecting you to discuss that, but I didn’t see the case for why you might choose the “green feature” to get a car that runs on “cleaner cheaper, domestic” electricity instead of gasoline. We all know that the world and we individually urgently need to get off fossil fuels, and switching to a vehicle that runs on an increasingly low-carbon grid is a good way to do that.

    • Venkat Srinivasan

      These are excellent points and I thank you for making them. I had thought that only the 2011 Volt had the issue with the tax rebate? And that the 2012 was expected to qualify. Is this not true?

  24. I think the metrics of the average American commute differ with your perception – or is it a Left Coast problem with distances between work and home. The stats say most folks commute less than 40 miles per day. I don’t know of an EV out there that can’t make one day with ease.

    More subjectively, that’s why my wife has decided that – once there is more choice [like the Ford Focus EV] available – she may finally replace her ancient Volvo. The one with 250,000 miles on it and still only uses 1 gallon per day.

    Her commute round trip is 24 miles. With something capable of just 80 miles, she could forget to plug it in at home twice – and still make it. A bit extra cost is still practical since we’re the sort of car owners who pick carefully and keep a vehicle at least a decade.