Tuesday, November 18, 2014

Are Electric Vehicles Really Better than Combustion for Commuters?

I have a pretty regular commute of about 50 miles a day. The wheels are about to fall off my ten year old auto, which still manages around 30 MPG given my highway driving. I'd like to swap out cars prior to abandoning it on the side of the road, so I started to wonder if now was the time to go with an all-electric car.

I've never liked the idea of hybrids. I'd rather mess with a combustion engine or an electric motor, not both. Electrical systems are crazy enough as-is without a gas-powered mobile generator strapped to it. Luckily electric vehicle prices have also come down significantly, with a base-level Nissan's Leaf going for under $22k. With that kind of price tag, I started to wonder how much better an all-electric car might be compared to a hybrid or an efficient combustion engine.

I started to measure my gas consumption and prices at the pump, and keep a running total in a Google Doc Sheet which I'm happy to share. After a month of driving, I started to calculate what the cost and the CO2 savings might be. I took current fuel costs and compared them to what an efficient combustion or hybrid car might be, then found some analogous kilowatt-hour data to draw comparisons to an electric vehicle. Here's what I found for a four-week period:

Current Car Efficient Car Electric Vehicle
Total Fuel Cost $119.52 $95.43 $40.81
Avg. Miles per Gallon 29.52 37
CO2 Created 802.59 lbs 640.65 lbs 511.62 lbs
Monthly Savings $26.25 $85.74

So an EV would reduce your fuel costs by 66%, however it would only reduce your carbon footprint by 36%. By comparison the "efficient car" reduces both fuel costs and carbon footprint by 20%. One would think that an electric vehicle would trounce a moderately efficient car in carbon dioxide production, but that doesn't appear to be the case.

Now, this is all based on an assumption that my data is sound... and maybe it should be reviewed by some more objective eyes. I'm effectively ignoring fuel transport and refinement costs (including battery production) - that's a rabbit hole I don't want to go down. I determined the CO2 output of gasoline engines using stats from U.S. Energy Information Administration and carbon output per kilowatt hour from the Environmental Protection Agency. Based on that info, I was able to determine the impact of either EV or combustion cars. This makes a few assumptions and generalizations for the different types of fuels being burned, such as ethanol mix and coal/natural gas combustion of power plants. Nissan's own "Feel Electric" Android app makes slightly different calculations than my own, using an "EPA formula" that equates one gallon of gasoline to 33.7 kilowatts per hour. It also does not add CO2 emissions from power plants into its equation. Using Nissan's formula, the savings for a week's worth of driving was slightly different than mine:

If we assume my cost calculations are correct and we add the additional engine fuel costs to a 36 month lease, how would monthly car costs compare? Let's take a look assuming $2,399 due at signing, adjusting if more is due by prorating the amount across the term of the lease:

Ford Focus Ford Focus Electric Nissan Leaf S Tesla Model S Chevy Spark Mitsubishi i-MiEV Kia Soul EV
3yr Lease $256.74 $202.00 $199.00 $890.28 No Lease Listed $216.47 ?

Note this makes a combustion car about $50 more a month than a comparable electric vehicle. The Kia is an interesting EV, unfortunately no Kia dealerships in my entire state carry one. From here we can narrow down affordable leasing options to the Focus, the Leaf S and the i-MiEV. Let's compare these three across the features I consider mandatory:

Ford Focus Nissan Leaf S Mitsubishi i-MiEV Kia Soul EV
Price $202.00 $199.00 $216.47 ?
AC Power (kW) 107 80 49 81.4
Horsepower 143.38 107.2 65.66 109.076
Battery Capacity (kWh) 23 24 16 27
Average Range (mi) 76 84 62 93
ABS Yes Yes Yes Yes
Traction Control Yes Yes Yes Yes
Bluetooth Yes Yes No Yes
Quick Charge Optional Optional Standard Standard

The i-MiEV seems a little underpowered and overpriced by comparison, however it did have several other amenities that the others lacked including more charging options. The Focus did offer considerably more power than the Leaf at a comparable price point, at the cost of average driving range. Another big difference is that the Focus has a water-cooled battery enclosure, while the Leaf's batteries are currently air cooled. This may extend the overall life of the Focus batteries, however this may not be a big issue for a 36 month lease.

The Kia Soul appears to be the stand-out performer, however it is off the list due scarce availability. I attempted to give the Focus a test drive, but after searching I found that I would need to travel 8 hours and cross three states to find one. That means the Leaf is the only one I can test drive, even though it ranked a close third by comparison.

The take away message is that the cost savings may be enough to trump a comparable combustion car by significantly lowering fuel and maintenance expenses for commuters with a predictable travel schedule. The environmental impact isn't as huge as I expected... however I'm just measuring greenhouse gasses and not contributors to smog, runoff or noise pollution. We may not have to weigh that impact however - the economics now seem to carry the day for EV's.