Chevy Volt Adventure: Feb Diagnostic Report

Just got the February vehicle diagnostic report email from the Volt. I'm not sure why I find it so cool that my car can send me email, but I do.

The salient numbers are:

35 kW-hr/100 miles

1 Gallon of gasoline used. [This is actually an overstatement as we have only used 0.2 gallons since returning from our Houston trip at the end of December.]

Our electricty usage for January (the latest numbers I have) was (numbers in parens are for Jan 2010):

Total kW-hr: 954 (749)
Grid kW-hr: 723 (455)
Solar kW-hr: 231 (294)
Dollars billed: $58.37 ($35.12)

$/kWh used: $0.06 ($59.00/954)

kWh/mile: 0.35 (35kWh/100miles)

$/mile: $0.02

Our bill for Dec was $32.00, so we spent an extra $26.00 on electricity in January, some of which can be attributed to the unusually cold winter we've been having. We also produced about 60kWh less this January than last.

But if we assume that most of the difference was the Volt, that means it cost us about $20.00 to drive the vehicle for the month. We used essentially no gasoline so the electricity cost was our total operating cost.

Looking at the numbers it also means that the draw from the car is less than or roughly equal to the solar we produced over the same period. Not that much of that solar went to actually charging the Volt since we tend to charge later in the day or over night after having done stuff during the day, but if Austin Energy actually gave us market rates for our produced electricity rather than the steep discount they do give us, we could truthfully say we have a solar powered car, even in January. For contrast, our maximum solar production last year was 481 kWh in August, with numbers around 400 kWh most months.

Compare this cost with a gasoline vehicle getting 30 mpg around town at $3.00/gallon (current price here in Austin):

30 miles/gallon = 0.03 gallons/mile * $3.00/gallon =

$/mile: 0.09

However, our other car, a 2005 Toyota Solar only gets about 22 mpg around town, which comes out to

$/mile: 0.15

Of course these numbers only reflect direct operating cost, not the cost of our PV system or the extra cost of the Volt itself relative to a comparable gas-powered vehicle, but that's not the point is it? Because it's not just lowered operating cost but being a zero-emissions vehicle most days and using (or potentially using) more sustainable sources of energy.

But another interesting implication here is what would happen (or will happen) when the majority of vehicles are electric? If our use is typical, it means about a 25% increase in electricity consumption just for transportation. What does that mean for the electricity infrastructure? Would we be able in the U.S. to add 25% more capacity in say 10 years without resorting to coal? How much of that increase can be met through conservation? It seems like it could be a serious challenge for the already-straining grid infrastructure, something we know we need to address simply to make wind practical (because of the current nature of the U.S. grid).

If Chevy and the other EV manufacturers can bring the cost down, which they inevitably will, people are going to flock to these cars because they're fun to drive, cheaper to operate, and better for the air. Given the expected rate of advance in battery technology and the normal economies of scale, it seems reasonable to expect the cost of electric vehicles to be comparable to gasoline vehicles in about 5 years. If gas prices rise even $1.00/gallon in that time, which seems like a pretty safe bet (but then I would have expect gas to be at $5.00/gallon by now after it's spike back in 2008), then the attractiveness of electric vehicles will be even greater.

Which is all to say that I fully expect EVs like the Volt to catch on in a big way in about 5 years, which I think could spell, if not disaster, then at least serious strain in the U.S. electricity infrastructure. I know the City of Austin is thinking about it because that's their motivation for paying for our charging station: monitor the draw from the car so they can plan appropriately. But are we doing that a national level? I have no idea, but history does not instill confidence, let us say.

Chevy Volt Adventure: Fun to Drive

We've been driving the Volt around town now for a few weeks and the biggest surprise to me is how much fun it is to drive. The instant acceleration, freaky smoothness, and weight-enhanced handling make it a lot of fun to drive. You can zip around, corner hard, and do it all without fuss or noise. And we haven't even tried sport mode yet.

As for the car itself, it seems to be holding up well--I haven't noticed anything particularly tinny or annoying, with the possible exception of the charge port cover, which seems a little weak but then it's just a little cover, but the latch is a little less aggressive than I'd like--a couple of times I've thought I pushed it closed but it hadn't caught.

We are clearly not driving in the most efficient manner because our full-charge electric range is currently estimated at about 30 miles, which our Volt Assistant at GM assures us reflects our profligate driving style and not an issue with reduced battery capacity.

As a family car it's working fine. With our around-town driving we've only had to use a fraction of a gallon of gas when we've forgotten to plug in after a trip. So our lifetime gas usage total is about 8.6 gallons, of which 8.5 were used on the round trip to Houston.

Chevy Volt Adventure: Houston Trip 1

On Christmas Eve we loaded up the Volt and headed to Grandma's house in Houston.

The picture shows the cargo area loaded for the trip. The cargo space is a little cramped but was able to accomodate what we needed for this trip, including all the gifts. It would be hard pressed to hold three full-sized rollaboards.

In the car we had me, my wife, our daughter, and our dog, Humphrey (a basset hound). Everyone was comfortable but this is definitely a 4-passenger vehicle because of the bucket seats in back. The seats were reasonably comfortable for a 3-hour trip, comparable to what I'm used to from our other car, a 2005 Toyota Solara convertible.

The total round trip from our house to Grandma's house is about 450 miles. The trip meter reports we used 8.1 gallons for a trip MPG of about 51, which is pretty good.

In our Solara, which averages about 22 MPG overall and gets probably 30 or so on the highway, we usually fill up at the halfway point out and back, using a full 15-gallon tank over the course of the trip. On this trip we didn't stop to fill up until the return, when the tank showed 3/4 empty. I put in about 6 gallons but I think the tank didn't fill (it was the first time I'd put gas in so I had no idea how much to expect to need—the tank must be 10 gallons if 3/4 reflected an 8-gallon deficit).

On the way out the battery lasted from Austin to just outside Bastrop, about 30 miles. It's clear that, as expected, highway speeds are less efficient than around-town speeds. I'd be interested to know what the efficiency curve is: is it more or less linear or, more likely, curves sharply up above say 50 MPH. My intuition says 40 MPH is the sweet spot. I tried to keep it between 60 and 70 for most of the trip (the posted limit for most of the trip is 70). I drove a little faster on the way home having realized that it didn't make much difference in efficiency.

Highway driving was fine. The car is heavy for its size, with the batteries distributed along the main axis, which makes it handle more like a big car than the compact it is. Highway 71 is pretty rough in places but the car was reasonably quiet at 70. When we left I-10 in Houston there was enough accumulated charge to use the battery for the couple of miles to my mother-in-law's house.

It definitely has power to spare and plenty of oomph. There's no hesitation when you stamp the accelerator and I had no problem going from 45 to 65 almost instantly to get from behind a slow car on I-10. We have yet to try the "sport" driving mode but now I'm almost afraid to.

The car is really smooth to drive--like driving an electric golf cart in the way it just smoothly takes off and doesn't make any noise.

If we had a problem it was the underbuilt electrical circuit at Grandma's that served the garage—at one point when we had the car plugged in and charging the circuit breaker flipped (a 15-amp circuit)—turned out the circuit also served most of the kitchen, where we were busy preparing Christmas dinner.

If there is any practical issue with the vehicle it's the climate control—it takes a lot of energy to heat it. Houston was having a cold snap so we got to test the heating system. The multi-position seat heaters are nice but keeping the controls on the "econ" setting meant that backseat passengers sometimes got a little chilled. You do realize how much waste heat gas engines produce when you don't have it available to turn your car into a sauna.

It was also weird to get back from a drive and realize that the hood is still cold.

We spent the last week traveling in the Northwest and rented the cheapest car Enterprise offers, which turned out to be a Nissan Versa, a tinny little econobox. The contrast was dramatic and made me appreciate the Volt. The two vehicles are comparable in size and capacity (but not cost, of course), but the Versa had a hard time making it up to highway speed and sounded like the engine might come out or explode under stress or blow off the road in a stiff breeze.

Now that we're back to our normal workaday life we'll see how it does in our normal around-town driving, but my expectation is that we'll use very little, if any, gas as we seldom need to go more than 10 miles from home (our longest usual trip is up north to Fry's, which is about a 20-mile round trip). We'll probably take it out to Llano and Lockhart for BBQ if we get a warm weekend in the next month or so.

On the way back from Houston we ended up near a Prius and ran into them at the gas station. They were interested in how the Volt was working and we got to compare MPG and generally be smug together. I ended up following them the rest of the way into Austin, figuring they probably reflected an appropriately efficient speed.

And I'm still getting a kick out of plugging it in whenever I bring it back home.

Chevy Volt Adventure

My family is now the second (in Texas or Austin, not 100% sure) to take delivery of a 2011 Chevy Volt. We got it last night and it's sitting in the carport happily charged.

The car is very cool, very high tech. It sends you status emails. It chides you for jackrabbit starts (although I gather other electric and hybrid vehicles do as well).

It is freaky quiet in electric mode, a bit rumbly in extended mode.

The interior is pretty nice, reasonably well laid out, nicely detailed. The back seat is reasonably comfortable (I have the torso of a 6-foot person and my head cleared the back window).

Accelerates snappily in normal driving mode (haven't had a chance to try the "sport" mode yet). Handles pretty nicely (the batteries are stored along the center length of the vehicle, giving it pretty good balance).

We'll be driving it to Houston, about 500 miles round trip, in a couple of days. I'll report our experience.

Early adopters get some perks. We get 5 years of free OnStar service. We get a free 240v charging station from the City of Austin at the cost of letting them monitor the energy usage of the charger. We get a special parking space at the new branch library near us. The Whole Foods flagship store has charging stations--might actually motivate me to shop there (we normally avoid that Whole Foods because it's really hard to park and you know, it's Whole Foods).

One thing that will take some getting used to is not having to put a key into it in order to operate it. I kept reflexively reaching toward the steering column to remove the key that wasn't there.

Here's a question for you Electrical Engineers out there: what is the equivalent to miles per gallon for an electric vehicle? Is it miles per megajoule? miles per amp-hour?

I'm trying to remember what the unit of potential electrical energy is and coming up blank (not sure I ever really knew).

Oh, and since we have a PV system on the house and can control when charging takes place, I am going to claim that this Volt is a solar powered vehicle.