Electric cars, hybrids, and related vehicles


#1

After I turned on my solar panel system and discovered that it does, indeed, provide significant power even in the tail end of winter, I got on a kick of examining various cars driven primarily or entirely by electricity.

This is not, realistically, something I’m going to pursue. I currently drive a 1997 Toyota Supra Turbo, and it would be hard to give that up. Not that I drive much anymore, I currently put 1400-1800 miles a year on my car, which is why it only has 81,000 miles on it after 17 years.

Still, the idea of driving something that theoretically was powered by my roof, not a limited supply of fossil fuel, rather tickles my imagination. That’s probably theoretical, since my projected annual solar production is supposed to be a bit less than my current house consumption, even if it’s well outpaced consumption so far. In reality, I’d almost certainly still be paying utility rates to run an electric car, not getting the power for free from my roof.

This is even more true of most people and their 10-15k a year drives. I consumed 9,200 kWh last year. Transport with the most efficient electric cars today would add another ~400 kWh for me, and ~4,000 kWh for most people. That energy cost for transport, incidentally, goes up a lot if you figure it for a gas car, to about 16,000 kWh.

One of the interesting things about those figures is that that electric cars are much more energy efficient than gasoline ones, not merely better in terms of emissions and such. The EPA publishes “MPGe” numbers for electric cars and plug-in hybrids running in pure electric mode, and those generally run from 90-110 MPGe. That’s based on the energy content of a gallon of gas, which is 33.7 kWh.

Why is this? It’s not weight or aerodynamics, an Accord Plug-In gets 115 MPGe vs. 29 for the gasoline version, which is 500 pounds lighter. It’s waste heat. An internal combustion engine is essentially a device for turning heat from burning gasoline into kinetic energy, and a lot of that energy goes into waste heat, which is why cooling systems are so critical.

Of course, the same is true for a big power plant. Typically about 67% of the energy of a power plant goes into waste heat. There are some natural gas combined cycle plants than cut that to about 55%, but 67% is more typical. I’ll ignore transmissions losses because they’re quite small, and we’re not counting distribution cost of fuel against cars either. Taking that into account, the Accord Plug-In’s efficiency on electricity is about 38 MPG. Combined efficiency when running on gas is about 46 MPG, higher than my estimate of the real fuel efficiency in electric mode.

On the other hand, even if running on electricity may not be as efficient overall as burning gasoline locally, electricity allows for non-gasoline power sources. Like my roof. That does mean either an electric or “plug in” hybrid, rather than just a hybrid. The “plug in” moniker meaning that the car has a large enough battery to operate in all-electric mode. Usually not far, often 20 miles or less, but regular hybrids with their much smaller batteries can’t do that at all.

The next question is, would you want to drive the car? I’ve long associated electric or hybrid with tiny, underpowered cars, but that’s no longer the case.

There’s the Chevy Volt. My knee-jerk reaction to the Chevy brand is “no,” based on repair records and relatively crappy ergonomics of Chevy rentals I’ve driven. It’s an interesting car, though, since it’s really a pure electric car with a built-in gas generator to recharge the battery, unlike most hybrids where the gasoline engine drives the wheels directly. 149 HP isn’t exciting, the electric range is 38 miles, 98 MPGe on electricity, 37 MPG on gas. The cheapest of the larger electrics at $28k after tax credit.

I mentioned the Honda Accord Plug-In, which is fairly similar to the regular Accord. 195 HP, electric range of 20 miles, 115 MPGe on electricity, 46 MPG on gas. About $37k after tax credit. If I weren’t already spoiled by my Supra, I’d seriously consider a plug-in Accord.

There’s the Tesla S, which is a prime example of what electric cars can be. It’s a luxury sedan like the Accord. The least-expensive P60 has 300 HP, range of 240 miles, and 89 MPGe. The big issue of course is that electricity is the only option, so range critical where it isn’t with hybrids. Tesla’s putting up Supercharger stations around the country that will rapidly charge your vehicle for free, though you have to pay extra for access to the Supercharger network if you’re buying a P60 instead of a P85. It’s possible at present to cross the country or go up or down either coast via the network, but there are still lots of areas that are out of reach. Including the the Supercharger access, which I see as required, and including the tax credit, a P60 is about $66k.

Personally, I wouldn’t touch a Tesla S. I kept running into reports of serious ongoing kinks. For example, people at Edmund’s have been driving an S for a while, and Tesla has had to replace the battery once and the powertrain twice in the first 20,000 miles. That, and Tesla requires that you sign up for $600 / year maintenance, or they void the warranty. That’s nontrivial. Still, it’s a clear example of what’s possible.

Porsche has a plug-in hybrid sedan as well. I know “Porsche sedan” is weird, but it’s meant to compete with the BMW luxury cars, and incidentally the Tesla S P85. 400+ HP (!) which as you might expect is mostly a powerful gasoline engine. Efficiency is underwhelming at about 46 MPGe on electricity, 15 mile range on electricity, and only ~26 MPG on gas. Still, I’m sure this car would give me an experience like my Supra… for $95k or so, depending on options and accounting for the tax credit.


#2

I live in NYC so this is all academic, but I would never purchase an electric-only car due to limited capacity and very long recharge times in batteries today.

Tesla clearly has the best hardware, and the higher-end Tesla S has a listed 265 mile range, probably 200 miles driving realistically. It takes ~20 minutes to charge to 50% at a supercharger station, if you happen to find one when you need it. But that’s 20 minutes of sitting in your car doing nothing, and that only gets you 50%, another 100 miles. And that’s at a supercharger, and there aren’t many of ‘em. That’s an $80k car that probably wouldn’t get me from my apartment to my parents’ house 4 hours away.

Battery capacity/power density is constantly improving, every single year, but charging speeds really aren’t. I suppose if capacity literally doubled, 400 miles would be enough for the vast majority of reasonable use cases. That’s enough capacity to treat it like a car that you only need to gas up every so often, and enough for full roadtrips. But that’s a couple generations away.

What we really need are supercapacitors, because they can be quickly charged, just like pulling into a gas station. Barring that technology being invented and working, plug-in hybrid cars with internal combustion engines charging the batteries which move the car make the most sense for the near to mid future.


#3

One aspect to add to the wider discussion is that american cars (not sure about imports or non american made cars sold in the usa?) have been made to be incredibly gas hungry. Big engines, big gas usage per mile etc. That is all ‘by design’ from your Big Oil guys.

In relation to charge times for electric cars, what about carrying a spare battery pack? Do tesla have that kind of option and are there electric car designs that allow quick easy battery change-outs for that kind of practice. You could easily double the range of your vehicle with no need of special charging stations etc. Even better why not have the ability to charge the spare battery as you drive, to keep it fresh and topped up?

I’ve been looking at this a little as well, sort of in passing as i’m not quite ready to put the money down for a solar panel array just yet (it IS difficult trying to find the ‘best’ company to do the job, and the ‘best’ hardware (most efficient etc) to use, and i plan to incorporate wind and water generation into the whole scheme eventually), but it is being planned.

The situation i would look for is a system where i store my energy locally, and have an electric car that simply charges up overnight, that i would use to get around locally. I don’t mind if the car is small, not sporty etc, it will be just for the local commute, but if it could carry a second battery to double the range that would be cool (i suspect the battery arrays are too large to be able to do a change without a workshop though?).


#4

A spare battery for a Tesla Roadster weighs nearly 1000 pounds. Not very portable.


#5

There’s no need to invent a shadowy ‘Big Oil’ conspiracy to make thirsty engines, simple economics explains it well enough. Americans traditionally had access to filthy filthy cheap gasoline/petrol and as a result consumer buying decisions for vehicles did not in any way value efficiency. Consumers gravitated towards big cars and big engines and so that’s what the manufacturers produced. When the price of gas has spiked historically then Americans have quickly turned to smaller cars and smaller engines in response.

The only piece of American vehicle buying habits that isn’t explicable by simple supply and demand is the governments bizarre tax structures which incentivize trucks and SUVs over smaller cars.


#6

I used to drive an older Chevy Malibu, which always felt rickety and cheap. I’ve ridden in a few Chevy Volts and, frankly, I’m impressed by them and was suprised they were Chevys. It’s likely I’ll be getting a Volt or something similar (electric primary with backup back generator for certain situations). I live 8 miles from work and my office has several plug-in stations along with a solar array covering the parking lot.

For the Tesla super-stations, I suspect we’ll start seeing those super-charge stations turning into little communities with resturants and little shopping areas. You’ll have a captive audience for 20 - 45 minutes while people charge up on their road trip. The same thing happened around gas stations along route 66 and similar areas back when road-trips were more about the journey and less about getting there as quickly as possible. That assumes the Tesla explodes in popularity the way analysts are predicting it will, and also assuming that other electric cars will be able to use those super-charge stations as well.


#7

Yeah… that assumes people are willing to change their habits, and cool as the Tesla is, I doubt that very much. Very few people are willing to give up convenience. For electric-only cars to take over the market, they need either much faster charging or much larger capacity so you can just charge overnight. The former is unlikely to happen with batteries, but supercapacitors could do it. The latter seems like manifest destiny, but we’re still a couple years away.


#8

Oh man, I just had a horrible vision of a proprietary car-charging dongle dystopia, where charging stations have like 12 different adapters to fit all different models of cars, and half of them are broken at any given unit.


#9

Why take over the market? Many families are two-cars these days. The electric car can be one of them.


#10

What ever happened with the Nissan Leaf


#11

That’s pretty much where Tesla is. Even the 60 has a 210 mile range, which is plenty for anything but a serious road trip.

Now, it’s true that the charging time is a real issue with longer trips. I do one of those roughly a year, to Virginia and back. However, it’s not nearly as bad as you might think. Jason Kavanagh of Edmunds.com took a Tesla P85 to visit his parents last year, a 890 mile trip from Los Angeles to Covallis, Oregon. He didn’t find the charge times onerous because they were breaks for rest and eating that he felt he would have taken anyway.

He mentions that his longest leg was 198 miles between chargers, and he used 221 miles of estimated range to cross that gap. It sounds like the “realistic” range of the car is about 240 miles - dinging it down to 200 is overdoing it. Nor does cold weather change that as much as you’d think.

When I said I wouldn’t touch a Tesla right now, it wasn’t so much about the range, it was other factors. The regular trip I make to Virginia is well within the current Supercharger network.


#12

Nothing happened to the Leaf. You can buy one today if you want. There are some on dealer lots within my area.


#13

Cost, practicality, and inertia.

As I’ve noted before, electric cars generally shift pollution - they don’t reduce it. I also think the current battery driven paradigm just won’t work. We’re not going to see huge gains in energy density or recharge rates. Not to the point where battery cars can compete with gasoline in any reasonable fashion.

I would more interested in solutions that do away with the battery as gas tank model.


#14

We’d love to do this, if we could find an electric car that was affordable. Until then, we’ve got a hybrid for the “small(er) car” role.


#15

I was wondering because at one point it was a moderately big coming thing along with the Volt but earlier in the thread the Volt and Accord were mentioned without mentioning the Leaf.


#16

I didn’t mention the Leaf because I wasn’t interested in it personally. Mostly it’s that it’s a tiny, underpowered car. It also has a very limited range (75 miles) and it doesn’t have the Tesla’s support network of Superchargers. It’s fine if you want a car that’s dedicated to commuting which can’t do anything else.

There are a lot of other cars I didn’t mention because they didn’t interest me personally, like the Prius plug-in hybrid. The Accord plug-in is about the minimum I could see driving, and for the moment I’d still rather drive my Supra.


#17

I’ve had a Volt for the last 18 months, and have been pretty impressed with it. I use it for a ~35 mile round trip commute, and I get from 35 to 45 miles on a full charge (11.something kwh). I’ve used ~85 gallons of gas in 18 months, and most of that was on trips from Philly to Boston and back. The build and engineering on the Volt are completely solid, and I’m anticipating my first service visit at 2 years, for the recommended every-2-years-whether-you-need-it-or-not oil change.


#18

That works out to about 107-137 MPGe, which seems a little high, but hey, you’re the one driving the car, you should know. Official figure is 98 MPGe.

I’m not sure how efficient the charging process is. Car & Driver claims it took 13 kWh to replenish 9 kWh at 120v, and mentions that a level-2 240v charger is probably more efficient. Assuming something similar, and my $0.19 per kWh rates, that’s about $0.07 per mile, which is something like driving a car with 50 MPG in terms of fuel cost.

You should probably get service a lot more often than every 2 years. Yeah, your gas engine isn’t seeing much use, but the rest of the car is, and should probably be checked.


#19

Our uni started building solar powered recharging stations for electric cars about a year ago. Only a handful, but they’re slowly getting more popular. Given the high fuel costs here (over $2.00 a litre for my fuel type) they look increasingly tempting every time I pass. However, electric cars here only work as city runabouts, trapped forever to roam the streets of Darwin. My next car will almost certainly be a hybrid, and at the current rate of rising fuel prices that might be sooner than I’d have preferred.


#20

Plug-in hybrids - hybrids with a good-sized battery and an all-electric mode - are what make the most sense to me, since you get electric power for the common short trips, and gas for the longer ones. However, there’s still a significant premium for that extra battery capacity, so non-plugin hybrids with no electric-only mode are usually more competitive overall.