E-Drive Systems Delivers Plug-In Prius to California

It's a cool idea. I checked into it for my Prius...adds $10k to the cost, bringing my auto up to about $40k. I need to really want to make a statement here, because the economic payback is about 10 years, and I calculated that with $5/gal gas (not far off). But in 10 years, we'll likely be driving very different autos, or have as yet un-imagined ways of getting around.

I am curious on how environmental this is. It sure is cool to save gas by plugging your car into an outlet. But since half of US' electricity is generated by burning coal, wouldn't this defeat the purpose of being green and use renewable energy?

Source:
http://www.eia.doe.gov/fuelelectric.html

After all the effort hybrid makers have gone to educate people that they're different from electric cars,

http://www.toyota.com/vehicles/2005/prius/faq.html (see question #10)

those kinds of pictures (a Prius with a plug sticking out of it) are actually pretty counterproductive, despite the rational arguments about the benefits of plug-in technology.

I wish people would spend a little more energy upping the efficiency of all vehicles instead of trying to make the most efficient ones "more perfect", which is also counterproductive (in terms of winning people over, since it seems like eco-wankery).

JMO.

Joseph,

I see where you're coming from, but the thing is that stuff like this is what helps drive the technology that will make all cars more efficient. The eco-wankery of the Prius and Insight led to the spread of hybrid technology to the Civic, Camry, Altima, Accord, Explorer, etc. It also seems to have led to the Citronen cars that aren't hybrids, but save gas by cutting off the engine while idling at long stops.

Plug-in hybrids will be bleeding edge technology for wealthy greens and geeks for a while, while the rest of the market simply catches up to regular hybrid status or other simpler ways of increasing efficiency. But eventually it will lead to improved hybrid batteries, plug-in technology propogating across more models, and eventual Electric Vehicles.

There are a couple advantages from the green perspective of a plug-in hybrid. A major problem with conventional vehicles is the fact that they are non-point source (tail pipe) emissions, and limiting or controlling those emissions is much more difficult than point source emissions (like a smoke stack). [At least in today's regulatory arena] If you're generating electricity with coal at a power plant you can control those emissions with various technologies. And besides that, there are many clean sources of energy.

The other big reason plug-ins are good is the fact that coal is abundant in North America. No more tanker spills, no more dependence on foregin oil, no more nasty refining. That fact alone would make plug-ins worth it even if coal polluted the same amount as petroleum.

James,

How often is payback and lifecycle cost analysis performed in the average vehicle purchase? Customers want what they want, and things like "economic logic" may not come into play. This is one aspect we cannot continue to discount.

Why do people keep touting the bogus "100mpg" number for plug in hybrids? It just makes them look ignorant or dishonest.

Getting "100mpg" by plugging it in to "free" electricity is no different than getting "100mpg" by towing the Prius behind your motorhome half the time.

It may be cheaper ( no road tax on electricity from home ) and it may be efficient ( especially if you keep it under 35 to stay in electric mode ) but the only people who think they're getting "100mpg" are those who are bad at math.

E-Drive web site is incredibly deceptive:
" well over 1000 miles per fill-up"
"expect to see over 100 miles per gallon"
They're taking advantage of the loophole in the Prius software that measures efficiency only in miles per gallon since it has no clue you were giving it "fuel" in another manner.

I hope we don't have legions of suckers buying these, driving them home from work and then plugging them in during the peak demand periods, increasing the requirements on the grid and tapping in the "dirtiest" and most expensive energy sources.

Good comments. Most of the questions can be resolved at the EDrive.com FAQ and at the CalCars.org FAQ, including the fact that we talk about 100+MPG of gasoline plus electricity (at under $1/gallon equivalent, depending on electric rates, etc.), and that driving electrically even on the national (half coal) power grid results in at least 45% lower greenhouse gases than an internal combustion car (on a "well-to-wheel" basis, i.e., apples-to-apples, counting all the emissions at every stage.

Felix Kramer, Founder, The California Cars Initiative

Do they plan on not making it stupidly expensive?

Great idea!
Way too expensive!

Mike - That's naysaying for the sake of naysaying. It's still going to be a lot cheaper and cleaner for me to use a plug-in hybrid than to fill up at the pump. My electric grid is mostly natural gas with some hydro and wind, although I pay extra to supposedly have all of my power come from renewables (though how those programs work is another story). Moreover, I have friends who've installed PV solar panels on their house that spit more electricity back into the grid than they ever draw from it, giving them a $0 electric bill every month. If those folks had a plug-in prius it would essentially be a mostly solar-powered car.

And for certail folks, that car essentially would make a tank of gas last months. My wife, for example, has a 7 mile (each way) commute that she can't do by public transit and she can't really bike. If she had one of these cars and drove all the back roads to work, it sounds like the gasoline engine would never kick in.

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James Barker,

I remember when only really, really rich people had cell phones. I remember when computer systems were several thousand dollars, not several hundred. I remember when only professional digital cameras costing thousands of dollars had 6 megapixels. I remember when DVD players were outrageously expensive. Hell, answering machines used to be hundreds of dollars.

This is brand new technology, not supported by Toyota. As technology scales up, it tends to become better and less expensive every year. If Toyota were to adopt this technology, I'm sure you would eventually see a plug-in option adding only $2K, not $12K to the cost of a car.

Hell, as it is Toyota has committed to keeping the "hybrid premium" under $2K, which will make hybrid technology itself cheaper than it currently is.

Right now 10K for a plug in feature is crazy, if we hit $10/gallon, err, not so much. Anyway I love seeing all the research and developement that is going into hybrid tech. It filters down into better, lighter battery tech, lighter, smaller and more efficent motor controlers. Electric powered accessory equipment such as AC and PS. These advancements will and are improving the efficency of all light motor vehicles.

One question, on a "conventional" hybrid the battery state when one gets hoeme I assume would be somewhere between fully charged and empty. Without adding more batterys would there not be an advantage to have the option of plugging in to fully charge the batterys overnight. Might add a few MPG with little cost.

Another idea for the automaker would be an extra battery pack(s) to extend the electric range of the vehicle as a plugin conversion does now but make it easily to remove and have the pack conform to part of the cargo area of the vehicle. Not so crazy because say I'm going on a highway trip, I need extra cargo space and since I'll be using the gas engine removing the extra batterys saves vehicle weight.

Hey make 'em fit the cargo floor of the trunk and then make them stackable. If you want to buy more electric range you buy more stacking battery packs till you've filled up the trunk. Since most people commute alone or with one other person and have no need for cargo other than a bag or two from the store which can go in the back seat, why not.

These may sound like crazy ideas but then again I'm sure many of the inventions we use everyday did in their day.

Why would anybody want to diss a 100mpg plug-in hybrid?

Isn't a 100mpg car good? Isn't it better to reduce depenedence upon foreign oil sold by Venezuelan dictators or the House of Saud? No imported oil for the US = no more wars.

Isn't a coal-fired plant more efficient than a gasoline auto engine? Isn't it cheaper? Aren't power companies expanding to offer electricity from wind, solar, tidal, and plasma arc (garbage) sources?

And those egalitarian bean counters who fret about how the common people can't initially afford such technology need to be patient. If it's a good idea, works, and people don't mind paying for it, then it will filter down to even the cheapest Korean econoboxes.

This is a good idea. It's progress. Kaizen!

I think of it as a nice option for people who have the right situation, such as folks who have a garage or parking spot next to their house, and have solar panels or get their power from a 'green' provider.

Right now, as a renter parking a block away from my house, it's a useless option. But when I buy a house, I'll definitely be using 'green juice' of some sort, and I will seriously consider a plug-in vehicle.

"Why would anybody want to diss a 100mpg plug-in hybrid?"

Perhaps the corollary to that should be asked as well - why not provide legitimate critiques to them? Shouldn't we consider all of the aspects, both positive and negative?

Here's the drawbacks of the technology:

1) At this point, it's very expensive to modify a hybrid into a plug-in. No way will it ever pay for itself.

2) Losing cargo space and adding weight, which changes vehicle dynamics and usability.

3) Added batteries means added waste, just like pure EVs.

4) Plugging in confuses people in this early stage of hybrid technology, since it's taken a lot of effort to convince people that they don't need to plug in hybrids to use them, unlike EVs. Now we're telling them to plug them in again.

5) MPG claims, etc ignore that the power comes from somewhere and is neither free from an economic sense nor from an environmental sense.

6) Mods to existing hybrids will void the warranty and possibly cause major problems with the operation of the vehicle, which could be very expensive.

7) The idea that these will be plugged in at night using spare grid capacity ignores that employers might have plugs at parking spaces etc, and as battery technology improves in terms of recharge times, people will "fill up" with electricity at peak times -- all of which will increase our electricity peak demand needs, and hence, increase infrastructure and capacity requirements.

8) Generally hybrids like the Prius can't go in all-electric mode past certain velocities or certain acceleration scenarios, so plug-ins won't perform very well for people who commute via highway -- which is most people.

These are just some drawbacks that come to mind that should be addressed, not dismissed as irrelevant.

What's needed to prevent companies like EDrive from scamming the public is a measure of efficiency other than MPG that covers all the various vehicle fuel methods. BTU per mile perhaps? Joules per kilometer? If EDrive and the gov't agencies who make a living were honest they'd provide real comparisons. A Honda Civic gets this mileage, a Plug in Prius gets that mileage, in a manner that compares all the fuel the vehicle consumes. They don't. And if they did I'd be surprised if they didn't compare the "drive under 35 most the the time" numbers of the plugin with the EPA values of the gas powered. If they had the nerve, or were more honest, they'd do the comparison considering all the fuel AND they' drive the plugin on the same EPA test cycle as a gas vehicle is tested with.

A "dollars per mile" comparison would be a good one as well. Yep, it's cheaper to drive a plug in ( if you drive it the proper way ) but again this is also made so by avoiding any road taxes. You could save considerable money driving with farm diesel or non-taxed propane, but that wouldn't be legal.

And there's always the argument: My electicity only comes from clean sources. Unless you're charging purely from your own PV panels on your house you're going to be tapped into the grid. If plug in after work during a peak demand period you're still helping to make the system fire up a gas or coal or oil plant somewhere to meet that peak load.

More efficient vehicles are good. Electric vehicles that don't spew out pollutants are good. Electric vehicles that don't consume power when stopped in traffic are good. Saving money is good. My problem is that companies and organizations who aren't content with that but resort to hyperbole, exaggeration, and outright deception to try to prove their point or sell their product.

OK Returning to earth present day:

1. Very true, like I said 10K for the mod, no unless gas gets very expensive.

2. True but as I said, how many people commute in a car alone and with no cargo. The gains in battery capacity offset the weight by several factors.

3. Very true however there is battery recycling.

4. Totally correct, many people will not understand and thus stay away hybrids.

5. True again but some poeple get their power from green sources.

6. That's why I say we need to get the manufactures on board. Make it an option. Solve #4 by having their adds saying you can have it with or without.

7. Right, unless the power provided an an employee lot is off grid solar or something best for plug-ins to be charged at night after peak usage hours.

Again, and I wish people would finally understand this, it's too expensive because the batteries are too expensive. The batteries are too expensive because they are not yet in mass production. The reason lead acid batteries are dirt cheap is because we've been cranking them out by the millions for a century. Solid state li-ion batteries, which right now could already be coming off the production line like paper mylar off a printing press, are held in limbo, NOT by any technological difficulties, but by LICENSING difficulties, meaning the people who own the patents are in no hurry to see these things mass produced. Please people, you're talking in circles... stop putting the cart before the horse... resolve the political/institutional hurdle first!

How about installing solar panel on the roof of the car? That way it doesn't even need plug-ins.

Joe, see: Solar Powered Toyota Prius Project.

Solar power in a vehicle may be nice for trickle charging, but the key benefit of Plug-in Hybrids is that you can essentially get the best of both worlds, plug in at night when utilities are dumping cheap electricity. See http://www.calcars.org/vehicles.html for more. Then eventually when the grid connected vehicle is fully developed, you can sell power back during peak periods from your ultraclean generator under your hood parked in the parking lot!

>>people will "fill up" with electricity at peak times

Clever people would plug their car into a vacation timer, which could be set to not let your car start charging until, say, after midnight.

Even more clever would be if your car's charger actually had a similar timer built-in.

>>people will "fill up" with electricity at peak times

Clever people would plug their car into a vacation timer, which could be set to not let your car start charging until, say, after midnight.

Even more clever would be if your car's charger actually had a similar timer built-in.

Great Idea!
I personally would not buy it above 3-4 Gs.

Just picked up my new Prius today. This car is hands down far and away the best car I've ever had. And I've had many.

When they get this expanded battery technology working - I'm buying it. Save some oil for my grand kids.

I suppose asking fo a felx fuel (E85) plug in Hybrid would be asking too much? Maybe if we pushed GM for one they may not go out of bussness

Tim Russell - I really like your idea of having extra batteries configurable by the vehicles owner. You can add more battery capacity as your needs and budget dictate, just buy another battery module and snap it in.

Couldn't a current hybrid achieve greater efficiency if it just knew how long your daily commute was? Knowing it only had to travel say 20 miles a day, it could allow for greater depletion of the existing battery pack, knowing that it'd be plugged in to recharge at the end of the day. The only cost over a non plugin hybrid would be the cost of the charging equipment and the modified software.

FlatGreg - Good idea, the computer could learn your driving pattern and then adjust how the car makes use of it's available energy sources. The ICE is always there so your never stuck if you make a longer than normal side trip on the way home. The only thing is I believe with the current batterys they keep them between a max and min charge level to maximize the life of the battery pack. Newer battery tech is making this less of a problem however and hybrids are driving much of that research.

I have a 2005 Prius and notice that it gets poor mileage when cold. So going on short trips has poor mpg. I would like to see a plug in heater that would pre-heat the engine. I estimate about a 20% improvement in MPG for a 5 mile trip. - small compared to a bigger battery, but not a negligible factor.

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editor note: You are right about cold engines. It's not just for hybrids; all gasoline cars get really poor mileage when cold too.

I would think that adding a block heater to speed warm up would help any car that's parked outside in winter. Also for emissions the sooner the engine warms up the quicker the computer goes to cleaner "closed loop" operation. The human in the car likes it to be warmer quicker too at 0 degrees F.
:-)

I have thought for some time that a plug in hybrid was a great idea. The fact that it costs 10 grand to convert a Prius to be plugged in only exists because it is a modification to a preexisting car. If the manufacturer would include this feature, then the cost would be almost nil by comparison. Hopefully such a thing will actually happen soon.

The comment about having solar cells on the house to make the power even cheaper is also a great point. The initial investment for the solar cells is a bit high though. Counter this with the fact that a set of solar cells on the house is sure to drive up the value of the property. Let’s all remember that home wind mills are a reality as well. I think that the federal government needs to offer more incentive to home owners to install these kinds of clean power generating devices. Germany is currently leading the world with this kind of legislation, and it has had a huge impact on the way that Germans get their power.

Never mind that the energy source may be coal. There is no reason that a coal burning plant can't be made clean. Obviously it would still produce CO2 which is bad, but eliminating the particulate, hydrocarbon, CO, and unstable compounds of nitrogen emissions is good, and reasonably easy to do. It just needs to get done. It is up to the fed to make clean burning coal plants mandatory.

I also want to mention something that is a bit off topic, and that is the concept of a diesel electric hybrid. Diesels have a reputation for being dirty engines, but that reputation has become more of a myth than a reality lately. Modern fuel injectors, particulate traps, and catalytic converters have made diesel engines just as clean as gasoline engines. That is with the exception of sulfur emissions. Again, it is up to the government to mandate cleaner diesel fuel. I believe that cleaner diesel fuel legislation has already been passed too. Diesels are much more efficient than gasoline engines, and so the cost savings are obvious. Also, any time less fuel is burned, less CO2 is emitted, so the environmental benefits are there as well. By the way, a diesel powered Audi just won the 24 hours of Le Mans, and it was the cleanest car on the track.

One last thing and then I'll stop preaching to the choir. Someone has already said this here, but it is worth repeating, and worth adding to. Cell phones used to be expensive, now they're cheap. Computers used to be expensive, now they're cheap. And so on. Along those same lines, the phone company (think Ma Bell) used to be a huge monopoly. It was so powerful that the fed had to break it up. Now that entire industry is nearly extinct. The American auto industry also used to be nearly invincible, now the big 3 include Toyota. Chrysler, which is practically owned by Mercedes, is languishing in 4th. GM and Ford similarly have been losing market share, operating at a loss for years, and are about to lose their positions as 1st and 2nd largest auto manufacturers in the U.S. These companies failed to keep up with technology, and in doing so sealed their fates. New technology continues to get better and cheaper. Those who do not keep up will lose out in the end. Let the technology move forward and to heck with the nay sayers. Their fates are sealed.

I think that adding some other additeves which makes it easy to combust is best thinking. I am also working on this project and i found good result and trying to lounch my product in India. From my view point Ethanol is cheaper and renuable source. thats why i am takeing intrest in this.

I bought a 2004 Prius, I love this car. My favorite drive time is when the Electric Motor is propelling my car, then the gas engine will eventually kick in when needed. The Prius is near perfection. The perfect Prius would have the ability to get much more Miles Per Gallon, and come with a Plug-In option from the factory. This would allow for All EV, or more Electric Vehicle only Propulsion. Also, The New Prius Would come with solar panels on the roof, and possibly other parts of the car. These panels could be an option package from the factory, but knowing Toyota, they would probably make it standard. I'm driving a car that gets well over 50 miles per gallon, And it's a Toyota; You are the Best.

Burning coal to create electrical power does not create more releases of carbon-dioxide than does burning gasoline in a car.

In fact the automobile engine is about half as efficient at suppplying energy to the wheel from the energy in the gasoline than any central power plant-battery-electric-motor combination. And the features of regenerative braking are more effective with a larger battery.

The raw energy source cost of coal is 13 times less than that of oil. At $20 a ton for coal and $60 dollars a barrell for oil. ((11,000*2000)/(20*100))=11,000 BTU/penny-COAL; ((120,000*42)/60*100))= 840 BTU/Penny- Gasoline; (11,000/840)=13. This makes it possible to run a car on coal-electricity far cheaper than on oil-gasoline.

The capital costs of the generating station and the oil refinery and the profits and the maintenance are the major cost of both gasoline and electricity.

It seems that the oil companies have delivered car fuel at far less a multiple of the input energy price than have power companies. Sieg Heil ENRON. But the energy is about 90% useable as compared to the maximum 20% energy useabilty of gasoline in a car.

Some people complain that the promise of nuclear power to "provide electricity to cheap to meter" has not been met, so that nuclear energy is a fraud. No one ever remembers that that this statement was made by a politician not an engineer or the president or major stockholder of a power company like Warren Buffet. Everyone knows that a politician's promise carries no weight after an election, but this was not even a promise only a prediction. Raw solar power and raw nuclear energy are both too cheap to meter. They are the same.

The uranium on the earth comes from exploded stars like our sun. Even some of the solar energy comes from the fission of the uranium and other elements that the suns gravity collects from stelar dust. a great deal of the geothermal energy of the earth comes from the fissioning of heavy elements inside the surface of the earth. A billion or so years ago, there were even large natural fission reactors that ran for millions of years near the surface where large concentrations of Uranium were formed. The billion years that have elapsed have now eliminated most of the type of Uranium needed for such a reaction. The remaining uranium can only be coaxed into reacting by high technology processes such as isotope concentration.

Uranium fissions by itself without a reactor, and has done since before the beginning of the earth. Since Uranium and Thorium are both heavy and present naturally in large quantities at the surface of the earth they can be assumed to be present in the molten metal core of the earth and in all other layers and adding heat to them.

The financing and operating costs of a Nuclear powerplant represent a far higher percentage of the cost per kilowatt hour than those of a coal fired power plant. The same is the case with hydroelectric power plants. The cost of the raw uranium purchased at the refinery can represent as low or lower than one thousandth of a cent per kilowatt hour produced, but the making of fuel elements from that uranium is ten to one-hundred times the initial cost of the uranium.

Uranium at one hundred times the current price does not even need to double the price per kilowatt hour.

At the very low price of ten cents a kilowatt hour, the cost of the coal to generate that kilowatt hour at the standard 30% efficiency of many coal fired power plants is about the price of one pound of coal or one penny. ((KWH/11300BTU)*(11300BTU/lb))= 1kwh/lb coal. ((one ton coal *(2000 cents/ton)/(2000 pounds per ton))= 1 penny per pound.

The power company would have the same profit if it only added one penny to the price per kilowatt hour when the price of coal doubled. They would only have to roughly double the price per kilowatt hour to maintain the same profit when the coal price went up ten times.

Right now the raw energy cost of electricity generated from oil is about fourteen cents per kilowatt hour in steam power plants.(11340/840)= 14. The price of the waste very heavy oil from refineries burnt in power plants is sometimes about half that of the refined diesel and may be less than that of crude.

To get 100 gallons of refinery product requires the input of about 123 gallons of crude oil on a contained energy basis. The electrical input of refineries has been said to be a substantial part of the energy in the produced fuel. The facts about this are not readily available. !!!!!But if it takes more than 7 kilowatt hours to produce a gallon of fuel, then gasoline should not be produced and the electricity should be routed directly to the car batteries!!!! This would save the extra 23 gallons per hundred needed to refine as well.

Seven kilowatt hours will power known electric cars a distance of about 35 miles and much better can be done by efficient drivers.

The prices above are coal revenues per ton sold by Peabody energy and an estimate of the current per barrell price of oil. The energy content of the two fuels is a general estimate.

The US government figures on average carbon dioxide release per kilowatt-hour generated does not show that burning oil produces even 3 percent less carbon dioxide than does burning coal.

The crude oils and heavy oils burnt in power plants have substantially the same contaminants as does coal. And modern collection methods and devices reduce the amount of these released to the air.

Car engines create far more of the pollutants, nitrogen oxides, than steam power plants, and at the steam power plants they are more easily captured.

The high energy density of carbon fuels means that a full electric car that travels long distances can be an engineering mistake and a public relations error even if the fuel engine is not used on one in ten trips. Sixty pounds (60#) of gasoline consumes about ten gallons of space, and the tank can be refilled at any service station. The ten gallons alone will give a well designed series hybrid a driving distance of at least 350 miles.

An engine in a car that drives only a generator can be made to operate a far higher speeds than one that needs to drive wheels and needs far fewer pistons because smooth operation at high torque at low speeds is never needed. Such an engine can run at much higher efficiency because it has fewer and smaller moving parts to create friction. It will also have fewer breakdowns. Modern fuel injection and valve technology, including electric valves, are easier to implement for the highest effiency, power and the lowest pollution because of the fewer valves. Only the the maximum average horsepower of such an engine is important because the batteries and modern electric drives can give any peak power needed or wanted.

One of the Disney parks has automobiles equipped with small highpower motorcycle engines because that is all that is needed for the stunt driving presentations. It would embarrass most big car drivers if they knew that they were only getting 15 horse power from their 300+ HP engine going down the freeway at 80 mph. Operating at 300 hp all the time would require 6.3 gallons of gas an hour in a very efficient vehicle. HG....

www.isomax-az.com is a manufacturer of an ICF Zero Energy Home; Take this 2 steps further. Solar panels and plug-in hybrids.

We call this a "Zero Energy Lifestyle" We are currently offering a Zero Energy Home +Solar panels+ plug-in Hybrid car in a new Subdivision in Apache Junction Arizona. MLS 2803009.

Take a moment to calculate how much money you would save each month if you didn't have utility bill for electric and didn't buy gasoline for 75% to 90% of your driving? That is after-tax discretionary income saved. How much of a raise would you have to get at your job or business to realize that much money after taxes? Our home will virtually pay you to live in it. This is real and it is available Right Now. You can be a person who is a stand for not needing more coal burning power stations, and no more holes in the Nevada mountains for 10,000 year storage of nuclear waste. Imagine clean air in our cities. We live next to a STAR. It powers all the natural systems on earth including the world ocean's current. We need to use that unlimited source of clean energy to power our homes and our cars. Thank you.

Being an owner of a Prius for about 6 months has taught me a lot, but especially, anyone driving any type of gas driven engine could learn how to get better gas mileage (MPG) if they would just keep their foot out of the accelerator. It's been harped upon for years that jackrabbit starts and quick stops make for poor gas mileage. Driving a Prius and noticing the display that shows your estimated MPG difference when one drives correctly or incorrectly to achieve the Best MPG is a great tool. $135.00 per barrel oil may make people drive more fuel efficiently sooner. The sooner we use less oil, the sooner the oil prices will come down. Over 500 miles on an 11.5 gallon tank is really cool on my Prius. Bring on an extra battery please.
Keep that hybrid technology coming.

Indeed big changes are on the way. High gas prices are for sure going to change driving habits. I've been working on mine already although I haven't noticed a 'significant' change in my fuel efficiency. I currently drive a Corolla and I get about 32 mpg. I'm trying to squeeze an extra 4 mpg to get the rated 35-36 by altering driving habits, but it's really hard to measure.

I can speak for whether it's 'better' to use more electricity for transportation. The answer is without a doubt, YES. Although using more electricity means burning more coal there are advantages in using more efficient plug-in hybrids.

1) Electric Motors are currently more efficient in terms of Joules-In/Joules-Out than combustion engines and are not limited by "Carnot Cycles". Theoretically the best efficiency a steel engine can attain is 37% and most engines operate around 20%. That's a shameful waste of energy.

2) Even if we burn more coal, the added pollution will still be localized. Ever wonder why the air around cities is smoggy and the air in the countryside is clearer?

3) Gas-electric hybrids are able to exploit economic equilibrium. If either electricity or gasoline becomes too expensive you can start using more of the other.

4) Corporations are naturally conservative. Companies don't care about clean environments. They only care about the bottom line and will only change if necessary. But if the corporations can make more money by increasing efficiency they will do so.