Energy

Why I chose the Leaf over the Jetta TDI – Renewable Journal for 7/4/2014

Tax credits and rebates, low cost of operation, and reduced air pollution all made the Leaf the better choice for my family.

[MotorTrend]For more posts in this series, please click here.

I know I’m going to get asked why I spent over 30k (before all the crazy tax rebates) on a car that only goes 80 miles. My father especially will ask at some point, and he’s already called it a “toy” car.

He’s not entirely wrong, either. I’m in my 40s now, and it’s actually quite a bit of fun to drive around in a car that can go from 0 to 60 in just a tad over 6 seconds. I’ve never had a car that has this kind of acceleration.

And my kids are bummed that a) it’s not black and b) it’s got a safety whistle that activates at slow speeds to warn pedestrians I’m coming. They wanted me to drive a full-on ninja car.

The Leaf is certainly fun to drive and all, but so was the Jetta TDI, which was my number #2 car after several test drives. The Jetta has nearly identical acceleration, more easily handles a rear-mounted bike rack, and has a much, much, much longer range than the Leaf does. So why did I go for the Leaf instead of the Jetta?

It was a combination of three factors: those crazy tax rebates I mentioned, the cost of operation, and the environmental benefits.

Leafy economics

The Jetta I was looking at was the lowest model that came with fog lights, so I was looking at about just shy of $26k. The Leaf was about $31k. However, since Nissan hasn’t sold 200k electric vehicles yet, my family can claim a federal tax rebate of up to $7,500. In addition, the state of Colorado has a $6,000 tax credit that we’ll get back as well. From what my wife tells me, it’s not a standard credit, but rather one that you get the full amount even if you don’t pay $6,000 in taxes. Assuming that’s right (and she’s the one who does all the taxes, so I’ll take her word for it), we’ll get an additional $13,500 of our state and federal taxes back next year.

So we can look at the price of the leaf as essentially $13,500 less than it was (although we couldn’t apply the tax rebates/credits to the down payment, unfortunately), or about $17,500. As good as the Jetta’s price was, it can’t touch this. Frankly, precious few vehicles can. So the up-front costs of the Leaf were way lower.

As for comparing the cost of operation of both vehicles, it’s helpful to understand how much I drove my Subaru Outback Legacy. So let’s look at my standard driving week for my Subaru over the last week or so:

  • Sunday: Miscellaneous trips to and from Home Depot and the grocery store.
  • Monday: Drive 30 miles round trip to work.
  • Tuesday: Drive 30 miles round trip to work, drive 10-12 miles round trip to kung fu class.
  • Wednesday: Drive 30 miles round trip to work.
  • Thursday: Drive 30 miles round trip to work, drive 10-12 miles round trip to kung fu class.
  • Friday: Drive 30 miles round trip to work.
  • Saturday: Drive 10-12 miles round trip to kung fu class plus some miscellaneous errands.

Add it all up and my usual weekly driving added up to about 210 miles per week, with a little more in winter since the Subaru had all-wheel drive. And all of that driving is well within the 80 mile range of the Leaf.

At the current price of diesel around my home (about $3.85), and using the advertised 42 MPG rating of the Jetta, the cost per week for me to operate the Jetta would have been $19.25. Going the same number of miles in a Leaf would take at most 70 kWh (at 3 miles/kWh, and I’m presently getting more like 3.8 miles/kWh). At the price I am presently paying Xcel for my electricity (just over 10 cents per kWh), the max cost per week for me to operate the Leaf will be just over $7.00. That’s a 63% reduction in cost of operation at today’s diesel prices and an even greater reduction as compared to my old Subaru (which used cheaper gas but got MUCH lower gas mileage). Add into the equation the even lower electricity cost once the solar panels are on the roof and the economics are even better.

And this doesn’t take into account the dramatically reduced maintenance costs (no oil changes, much simpler drivetrain fewer components to fail, fewer and cheaper regularly scheduled maintenance appointments, and so on) and the cost of operation is a no-brainer for the kind of commute I have.

Green Leafs

That leaves the environmental benefits. Most people living in Colorado get their electricity from coal, some from natural gas, and a small number from wind and solar. I pay Xcel a premium for my electricity so I theoretically get a portion of my electricity from wind. Realistically, however, Ampere’s Law and Kirchoff’s Current Law combine to mean that electricity is consumed close to where it’s generated. Since the nearest generators are coal and natural gas, the bulk of my electricity currently comes from fossil fuels. And in fact, if you look at the fuel mix for Xcel in Colorado, 56% is coal, 21.6% is natural gas, 19.3% is wind, 1.9% is hydro, and 1.1% is solar (including, soon, my home).

So let’s look at the amount and type of pollutants generated for electricity vs. gasoline and diesel. Due to the complexity of comparing full fuel lifecycles, let’s look at just the fuels themselves.

According to the Energy Information Administration (EIA), burning coal for electricity generates between 2.08 and 2.18 pounds of CO2 per kWh, while natural gas generate about 1.22 pounds per kWh. At the fuel mix that Xcel has for it’s regions of Colorado and plugging in my current driving efficiency of 3.8 miles per kWh, this works out to about 0.39 pounds of CO2 per mile.

By comparison, burning a gallon of diesel or standard gasoline generate 22.38 or 19.64 pounds of CO2 respectively. Using 42 miles per gallon (the Jetta TDI’s fuel efficiency) and 26 miles/gallon (my old Subaru’s), I calculate that the Jetta would emit about 0.53 pounds of CO2 per mile while the Subaru was emitting about 0.76 pounds.

Put another way, powered off Xcel’s mostly coal and gas electricity grid, my Leaf will emit about half the CO2 that my Subaru did and about a quarter less CO2 than the Jetta TDI would have. And that’s excluding the fact that, once the solar panels are up on my house, my electricity will be essentially carbon-free. Yes, there’s an energy payback period associated with the full lifecycle of solar panels, but recent lifecycle studies have found that renewable energy save far more carbon emissions than they create, especially compared to fossil fuels.

And the story is similar for comparing the Leaf to the Jetta (or the Subaru) with respect to emissions of standard pollutants such as mercury, carbon monoxide, ammonia, nitrogen oxides, particulates, sulfur dioxide, and volatile organic compounds – in every case, a Leaf powered by Xcel’s coal/natural gas mix emits far less pollutant on a per-mile basis. And again, the emissions of each pollutant is essentially zero once I make the switch to solar power.

So the Leaf made economic sense on both a non-recurring and a recurring cost basis and it made sense on the basis of every air single pollutant.

Pollutant Estimated 2014 Volkswagen Jetta TDI improvement over 2003 Subaru Outback Legacy (lbs/mile) Estimated 2014 Nissan Leaf improvement over 2003 Subaru Outback Legacy (lbs/mile) Estimated 2014 Nissan Leaf improvement over 2014 Volkswagen Jetta TDI  (lbs/mile)
Mercury 137x 4401x 32x
Carbon monoxide (CO) 353x 12339328x 34988x
Ammonia 200x 2346864 x 11734x
Nitrogen oxides (NOx) 28x 514949 x 18527x
10 micron particulates 19x 183171x 9652x
2.5 micron particulates 12x 139386x 11771x
sulfur dioxide (SO2) 123x 1800x 15x
Volatile Organic Compounds 151x 23325615x 154932x

The inevitable caveats

That’s not to say that the Leaf is perfect. It’s still powered using lithium-ion batteries from countries that are rife with corruption and poverty. Its motor still uses a lot of rare-earth metals that are presently mostly sourced from China. It’s still made with a lot of plastics that are made from petroleum or natural gas feedstocks.

And then there’s the electronics. As an electric car, what it loses in complicated mechanical mechanisms it makes up for in electronics. And modern electronics use all sorts of raw materials that are problematic, from toxic chemicals to super-powerful greenhouse gases to minerals (tantalum) that come almost exclusively from conflict regions. At least the Leaf isn’t designed to be thrown away like a billion smartphones….

Finally, the Leaf is still a car. The most energy efficient form of transportation ever devised by man is the bicycle, simply because there is so little metal required to move a person. When I’m driving my Leaf, the motor needs to move nearly 3300 lbs in order to move a single 200 lb man from place to place, compared to a bicycle that weighs, maybe, 20 lbs. So let’s keep things in perspective here.

To review, the federal and state tax incentives were amazing, so my non-recurring costs were much lower for the leaf than for a Jetta TDI. The recurring costs are $80-100 less per month just to drive the Leaf, and the scheduled maintenance will be much cheaper too. Even powered by my utility’s mix of coal and natural gas the Leaf will emit fewer pollutants than the Jetta, and the improvements get almost infinitely better once the solar panels get installed on the house. But for all that, the Leaf isn’t a miracle vehicle by any means. If you want one of those, get a bicycle.

Your mileage may vary, of course.

2 replies »

  1. After reading this, I’m sure the Toyota Tacoma I bought yesterday will emit from its tailpipe about 100 lbs/mile of pure guilt. Thanks a lot, Brian. 😉

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