A Little Math on the Nissan Leaf

I read an article in this morning’s WSJ about the Nissan Leaf. The Leaf, which will be out in 2012, is an all-electric vehicle. It’s estimated to go 100 miles on a charge. According to the WSJ, it’s expected to price out at about $33,720 (or $26,220 with a $7,500 tax credit). I haven’t read up on the tax credit so I’m not sure if it’s available to everyone or will be phased out for those in higher brackets.

My first question was:

“How much will it cost me to charge the battery?”

After installing a home charging station ($2,200 not including a tax credit), Nissan says that at an average of $.11 per kWh, it will cost $2.75 for a full charge (see here). Doing a little math, that works out to about 25 units (I don’t know what else to call it) of electricity used to make a full charge. I looked at one of my electric bills and determined that we are paying $.125129 per kWh. Multiplying that by 25, I get about $3.13 per charge. So, $3.13 per 100 miles. Our Rendezvous costs about 4 TIMES that much to drive 100 miles (averaging 20 miles per gallon and paying $2.50 per gallon).

Not counting other automobile maintenance, a gasoline powered car would have to get 80 mpg in order to get its fuel cost equivalent to that of the Leaf’s.

The 100 mile range is a significant drawback in my view (at least for my family). My wife has a 120-mile per commute so she wouldn’t be a good candidate unless she could plug in the vehicle while she was at work. Since I work from home, my driving is a lot less. I could be a good candidate. But, with three kids, we desire a bigger vehicle for family trips and stuff like that. That means, for us, my wife would have to drive the bigger vehicle to and from work.

Another consideration is that the number of miles between charges will decrease as the battery ages. And, these batteries could cost thousands of dollars to replace.

The bottom line for me is that I would consider buying one IF they could get more miles between charges. There’s talk of building charging stations but there wouldn’t be any in our area for quite sometime. And, a charging station would take approximately 30 minutes to fully charge the Leaf. What would be cool is if they could figure out a way to make batteries easily changeable. Then, Leaf owners could lease a battery and just change them out at a charging station rather than having to wait to charge them.

Finally, my other concerns are:

• What happens to all the spent batteries? Landfill or could they be reused?

• What kind of stress would all these plug in vehicles put on the electric grid? Would electric companies then have to charge more per kWh in order to make upgrades?

11 thoughts on “A Little Math on the Nissan Leaf”

  1. Another factor that you haven’t considered (which my auto mechanic mentioned to me) is maintenance/repair costs. If something in your new electric and/or hybrid car goes funky, you can’t just drive it to your local old-time mechanic that you’ve used for years. Not many people are yet certified on maintaining these vehicles, or have the equipment and experience. If you’re going to buy one – think ahead — who can and will fix it for you? (assuming you would take it back to the dealer for most things, but how much does that cost, and how far away is that)?

  2. Here’s another thing to consider in these “green” cars. The charge-battery-motor efficiency is probably about 20%. Transmission losses are small, with about 95% efficiency, but those lines probably lead to a coal-fired plant with about 33% efficiency.

    It may make you feel good, but it’s not so “green.”

  3. Let’s provide some simple facts:
    Tracy, your mechanic has an inherit bias in stating what he did, but the actual facts dispute that because, there are a lot less moving parts involved with the Leaf over an ICE, so the chances of something funky going wrong are a lot less than your present car and as a side fact the electric motor is less costly than a petrol engine to replace and much easier (much less labor) to replace. Also, Nissan claims that the first maintenance interval is 5 years on this car (show me a petrol vehicle with the same maintenance interval). Nissan is coming out with another 7 AV models in the following 3 years, so I think you can rest assured that Nissan will support it. Also, Nissan has open a training facility to teach their mechanics how to work on EVs.
    2) Nissan claims batteries will drop to at most 70% SOC (state of charge) anywhere between 7-10 years. At that point you can still use them as a power storage backup if you have home solar panels for another 10 years. Also, Nissan is working on collaboration with power utilities to use “spent” battery packs as reserves on the grid. Maybe some entrepreneur will come up with a way that homeowners can lease the used packs to the utility for grid stabilization.
    As for Jack’s comments:
    1) First the EV is designed to take 1/3 the energy to travel the same mile as a gas car.
    2) The charging efficiency on the Leaf depends on which of the charge phases you are in: Phase 1 (up to 80% SOC it is around 75% efficient; Phase 2 is up to 85% efficient. Please get your facts straight. The efficiency of the power grid you are charging off of is around a 30% loss or 70% (also dependent on where you are in the grid). If you have a home solar panels then who cares about efficiency since you will not be paying for it. Please also consider the efficiency of extracting from the ground, creating and transporting a gallon of gas. I think you can see who wins the efficiency argument.

    In my area the power generation is natural gas and nuclear so I don’t have the worries with coal, plus after getting the car I’m going solar at home to stick it to the power company anyway. I can see in 5 years or so laughing at all the gas drivers as they eat the $5/gal cost for gasoline and as their utilities rise with inflation (once our gov’t debt really kicks in).

    EV is a much better alternative because now you have a way to insure the cost will not rise over the next 10 years. Good luck with your 20th century technology.

  4. I read on a blog somewhere where someone said that “electric cars are the answer, only if the question is urban commuting”. Curt above seems to think it is his answer, but it isn’t for me. I sometimes need to be able to drive several hundred miles across the inter mountain west where charging stations are non existent and even gas stations are far between.

    If you don’t swallow the proposition that we will all die a horrible death from too much CO2, then the whole rationale for electric cars sort of crumbles. That’s where I am.

  5. I’m with you, Sam. I’m more interested in the economics. Does it make sense economically to drive a hybrid or electric vehicle? That’s what it’s going to come down to for most people.

  6. Yeah, it’s all about the money to me. There’s nothing better than sucking oil out of Earth, paying some dictator $100B/yr, or splashing the Gulf coast with sticky, poisonous goo. That’s the best we’re ever gonna do.
    I don’t have kids, and don’t give a damn about anyone else’s. They’ll just have to deal. I got mine!

  7. Buzz,

    Give me a break. No matter what we do, there are consequences. Electricity generated by nuclear plants produces waste that must be stored somewhere. Coal-burning plants cause polution. Wind energy’s not going to get us where we need to be.

    Let me ask you: what kind of car are you driving right now?

  8. True. All forms of energy use have consequences. But when we’re led around by our wallets, we often trade long term harm for short term gain.
    I drive a Porsche; ~3500 mi/yr. The rest of the time I ride a hybrid mountain bike (pedals + electric motor) the 12 miles R/T to work.
    Charged from my rooftop solar panels. I used to commute 60 mi each day but moved closer to work 15 yrs ago. Much happier, love biking to work and when I do have to drive, love that as much.
    Looking forward to owning a LEAF. Might just sell the Porsche.

  9. I should add: the aforementioned changes to my energy use profile have had a positive effect on my personal finances.
    My Porsche costs $1000 every time take it in to service. That’s now every 3 yrs instead of every 9 months. My electric bill is < $30/mo due to rooftop solar and a real estate agent from my church claims my house resale went up in value by more than the cost.
    I cancelled my gym membership. The bike rides are plenty of exercise. Maybe the LEAF will be a frill. But, it won't increase my oil consumption.

  10. Curt, you only mentioned the CHARGING efficiency. Electric motor efficiency is not all that good, either, and that must be factored in.

    Gas? Traditional plants operate at 33-35% efficiency. The most modern operate at 50-60%.

    Nuclear? Have you ever noticed that they are all on lakes and rivers? That’s because of the cooling requirements. All that heated water is lost energy.

    Solar? Are they free? No. Do they take a lot of energy to create? Yes.

    20th century technology? Well, the electric motor was invented in 1832, so you’ll be using 19th century technology.

  11. curt — I can see that you are well versed on this technology and I thank you for sharing your thoughts and information.
    I wasn’t trying to imply that purchasing a car like this is not a good choice. Not at all. I was just pointing out one more minute point that perhaps a buyer might not THINK about before purchasing (that they maybe cannot go to their long-time trusted mechanic). I wasn’t saying it was a reason to not buy a car – just a point to keep in mind.
    You gave some good counter-points to that, and I thank you.

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