Seven months with an electric vehicle

We have now owned our 2014 Nissan Leaf all-electric vehicle for about seven months. Here are some stats and reflections.

  • We’ve driven it 3,474 miles.
  • The car has used just slightly over 1,428 kWh. This is missing the few kWhs I put in at the dealership charger and a very few other locations which I did not record. A breakdown of energy delivered by charging level follows:
    • Level 1: 1,071 kWhs (mostly from the 110 volt outlet next to our driveway)
    • Level 2: 334 kWhs (all from Chargepoint public charging locations, which seem to dominate the Twin Cities market)
    • DC fast charging: 24 kWhs (almost all from Greenlots chargers, which are the most common in the Twin Cities)
  • All that energy cost us $183, or about $0.05/mile. A 2014 Nissan Sentra averaging 30 mpg in the city would have used $253 worth of gas at today’s super low gas prices (plus another $20-$50 for one oil change). Judging from used car ads, our purchase price would have been about the same as the used Leaf. So over seven months, we’ve saved about $100 is gas and maintenance.
  • Using Xcel Energy figures, driving the Leaf compared to the Sentra avoided 1,051 lbs of CO². It basically halved the greenhouse gas emissions associated with driving our car, the second largest source of emissions from a typical household.

Our driving habits haven’t changed much, although we take the other car if we’re venturing beyond the 394/494 ring in the winter. If you turn “eco” mode off, acceleration is impressive. Lots of people ask “is that car really just electric?” If Xcel Energy ever approves a sensible metering plan for electric vehicles, we could cut our charging costs over the same time period down to about $100, or almost half of what we paid the last seven months.

An exploration of gas tax revenues

I got into a twitter discussion the other day about mileage-based user fees versus gas taxes as a useful future revenue source for funding transportation.  There was an argument that the failure of gas taxes to keep up with funding needs is not about new alternatively-fueled vehicles coming online, but rather that the tax hasn’t really gone up for a decade and therefore, hasn’t kept up with inflation.

I don’t disagree with this as historical reasoning, but I was curious how this might play out in the future.  After all, we’re told the increasing numbers of vehicles fueled by stuff other than gas and diesel will lead to increasing shortfalls even as mileage (and therefore wear-and-tear on roads) may increase or stay the same.

In my twitter discussion, this argument wasn’t convincing to @sumnums.  After all, even by 2030, electric and other non-gas-taxable fueled vehicles will make up a small percent of the fleet.  According to the EIA 2012 Energy Outlook, electricity and natural gas (the only two non-petroleum alternatives worth measuring), will only make up something like 1% of the energy used for road transportation.

However, gas-taxable fuel (gasoline, diesel and E85), will see an 8.5% drop in BTU usage between 2013 and 2030.  So it’s not just alternative fuels, but fleet fuel efficiency that will impact gasoline consumption.  In the meantime, vehicle miles traveled (VMT) on roads will increase 28% (27% if you just look at light-duty vehicles) in the same time period.

What does this do to gas tax revenues? If rates remain the same (I’m using $0.20/gallon federal taxes as a compromise between gasoline and diesel rates), revenues will decline by 7.5% through 2030.  If you index gas taxes to inflation, as was suggested in my twitter conversation (say 1.4% annually), revenues will climb 17% through 2030.

Leaving aside for the moment the political hurdle of indexing gas taxes to inflation (not minor), would an increase of 17% be enough to support a 28% increase in VMT?  You could always bump the current rate to something you thought more acceptable and peg to inflation from there, but that’s an even steeper political hill to climb, plus it leaves you with the same mismatched rate of growth between VMT and revenues.  Maybe that’s not an issue, smarter people can decide, but I wanted to point it out.

Other issues with the figures could be argued: will VMT really grow that much?  If not, then perhaps the revenue issue isn’t as important.  On the flipside, is it really realistic or acceptable to have only 1% of road transportation energy delivered as electricity or natural gas in 2030?  If we started being adults about climate change in the next few years, couldn’t incentives/disincentives change that figure dramatically?  If electricity is providing 10% of the fleet energy in 2030, an inflation-indexed gas tax will only bring in 5% more revenue in 2030 than today (with EIA AEO VMT assumptions intact).  At 15% electrical energy, revenues are dropping even with an inflation-indexed rate.  In the meantime, the cost of road maintenance and materials will likely continue to climb.

Cities prepare for the electric car, but are they thinking about the roads?

Potholes - courtesy flickr user MSVG

The New York Times describes a number of cities, mostly in California, that are preparing their communities for the adoption of more electric vehicles. Primarily this means installing charging stations in public places and addressing code issues related to charging stations at single family homes. According to the article, San Francisco will soon have a new ordinance that requires new structures have the wiring to accommodate charging stations.

The article doesn’t address the other half of the auto infrastructure: the roads. To “prepare” for the electric car, and probably even an efficient system that doesn’t include the electric car, road funding needs to change. We already know that users now only pay about half of the cost of roads, which means there are no market signals for road users to choose the most efficient mode or “consume” an appropriate amount of transportation service (miles traveled). We also have some serious deferred maintenance issues.  If electric vehicles are adopted in large numbers funding for roads, which comes in large part from the gas tax, will continue to dry up.

So besides building charging stations and beefing up transmission infrastructure, cities, counties and states (and users, if they want good roads) should be advocating for a mileage-based fee, similar to what has been studied in Oregon and implemented in the Netherlands, to pay for road building and maintenance. The gas tax would probably have to stay, but as a way to put a price on carbon pollution rather than fund transportation.

This new mileage fee could be tacked unto your home electricity bill if you had a charging station, but that would probably mean a lot of creative solutions would pop up (solar panels) to avoid the fee. While this would have it’s environmental benefits, it wouldn’t solve the transportation funding problem. So the fee should be based purely on mileage, not the fuel used. Existing technology is adequate to provide a method to assess the fee, including addressing privacy concerns. The Oregon pilot has shown that this can work, it’s only a matter of political will to implement it.

US-China Electric Car Project Kind of Misses the Point

The BYD E6 Electric Car

The BYD E6 Electric Car

Andrew Revkin at Dot Earth has a good discussion with Lee Schipper about the problems with the US-China deal on producing electric cars.  Without repeating the post, the essence is that zero-emissions cars don’t solve the traditional problems that planners have been struggling with for a long time.

“Creating a zero-carbon car for China tomorrow won’t solve the much bigger problems of urban congestion, traffic fatalities and the paving over of once-beautiful cities to make room for more cars,” Dr. Schipper said. “The discussions should back up. Energy is only a means to an end. What are the ends, urban access and mobility, or cars for a small minority?”

This isn’t to say that China and the US shouldn’t be building electric vehicles.  Only that a carbon-free car is just that, a car, with all its other attendant issues and urban design challenges/drawbacks.