Electric Magic – It’s All About Efficiency

There are some serious advantages to owning and driving an electric car, including:

  • Convenience – you don’t go to the gasoline station and you don’t make individual payments for fuel. You plug in to a wall socket at home, which if you can operate a toaster you can do easily. The utility company of course bills you, monthly with all the other electricity you use.
  • Fuel Costs. About 2 cents per mile for electricity compared to about 10 cents per mile for gasoline.
  • Emissions. If everyone’s tail pipe was mounted in the center of the steering wheel, everyone would drive electric cars. If they did, everyplace would smell better. Never mind CO2 and global warming.
  • CO2 and Global Warming. Ok, we should probably mind it. Oh the planet will be fine, and it will inevitably cure itself of greenhouse gases. But a very small adjustment in our weather can have fairly devastating consequences for us as individuals.
  • Driving Pleasure. Yep. They’re more fun to drive. They accelerate better. They accelerate more smoothly. They are much quieter. They’re more fun to drive.

So where does all this magic come from? Well, it isn’t precisely magic. The electric motor actually predates the Otto cycle internal combustion engine and it was always simply more efficient at converting energy to forward motion. No, you can’t run your car on water by hydrolysis. You can’t hook a generator to the motor and make it make its own electricity. You can’t put solar cells on your car to extend the range signficantly. And you can’t use a windmill either. The physical laws of the universe still hold true and the ones pertaining to the conservation of energy hold particularly true.
But the electric drive train is just more efficient than the internal combustion engine. Not a little bit more efficient, about 5-8 times MORE efficient. And all good things about electric cars derive from that.
There are any manner of claims regarding efficiency of both electric motors and Otto cycle engines. And there are hundreds of ways to calculate it. I like to reduce it to the basics – energy into the car, miles driven out of the car. In this way, individual cummulative losses, while interesting, don’t drive us into heroic technical discussions.
To talk about energy input, we have to pick apples or oranges and do both sides with our selection.
Let’s talk about the energy in a gallon of gasoline. This should be pretty simple, but actually it isn’t. I’ve seen numbers all over the place. The reason for this is that gasoline is all over the place. There are actually a LOT of different formulations of gasoline. But the most common type you can buy at the pump today is termed REFORMULATED GASOLINE.
Basically, to reduce emissions, the government requires the gasoline to be OXYGENATED to achieve better combustion of the carbon and thereby reduce the PARTICULATES (soot/smoke) emitted from the tailpipe. Has nothing to do with CO2 but it does have to do with the aesthetics of SMOG in our cities and the smell of emissions.
They originally required an additive termed MTBE. Methyl Tertiary Butyl Ether. This is actually a combination of methanol and isobutylene more conventionally used to dissolve gall stones. But it was an excellent oxygenator for gasoline. Unfortunately, it turns out to be a deadly carcinogen that accumulates in groundwater and resides there essentially forever. This is probably THE classic case of government acting to reduce environmental impact, and instead increasing it, all the while requiring EVERYONE to participate, up to the point where they discovered they are wrong. In which case, they declare the whole episode a SECRET.
That’s correct. They very actively don’t want you to know about MTBE or that MTBE every existed. This in fact IS a conspiracy – a kind of conspiracy of embarassment. In any event, they have emitted their own emissions of the ridiculous notion of using ETHANOL as an ALTERNATIVE FUEL. It takes about 3 gallons of gasoline worth of energy to make a gallon of ethanol. I make whiskey in my garage remember.
But they have quietly replaced the MTBE with ethanol as an oxygenator. It takes a lot of it. And so the ethanol as fuel ruse. It’s a fuel additive and an economically and environmentally expensive one. But it will oxygenate gasoline, and it almost eliminates fuel line freezing and water in the tank. It’s much better than MTBE.
In any event, as best I can tell, the energy content of a gallon of 5.7% ethanol/gasoline, termed reformulated gasoline, is right at 111,836 British Thermal Units (btu) per gallon.
Lets talk about electricity. Electricity is commonly measured in voltage, amperage, and wattage. A volt can be thought of as a pressure, a difference in potential. An ampere is a measurement of the flow of electrons through a conductor. An ohm is a measure of the resistance of the conductor to current flow. A formula, ohms law, defines all three of these in relation to each other.
One volt is the amount of energy required to move one ampere of current through one ohm of resistance.
If you kept the resistance of the conductor at 1 ohm, but increased the voltage to 2 volts, you would get 2 amperes of current. If you then dropped the resistance from 1 ohm to 1/2 ohm, you would have 4 amperes from the same two volts. Their definition is pretty much defined by their relationship.
The basis is actually the number of electrons flowing, like water in a hose. Turn up the pressure, more water comes out. Make the hose bigger (lower resistance) more water comes out. Take away the pressure (voltage) no water. The flow of water is caused by the water pressure and limited by the resistance of the hose to flow.
If we want to measure power, we do so in watts. A watt is defined as 1 ampere of current at one volt of potential.
If we had 1 ampere of current at a 1 volt potential, and we let that run for 60 minutes, we would have consumed a WATT/HOUR  or wH of electricity.
To the electric service in our homes, it is typically delivered at 120 volts. And it is measured in kilowatt hours (kWh.). A kilowatt hour is simply a thousand watt hours. And so 120 volts, at a current flow rate of 8.33 amps, for one hour, is equivalent to a kilowatt hour or kWh.
You may have seen a light bulb marked 100 watts. That is how much power it would consume in one hour. And so the typical 100 watt light bulb requires a current of 0.8333 amps at 120 vac.
If you run the bulb for 10 hours, you have consumed 1 kWh of electricity. In Southeast Missouri, they have just raised the summer price of electricity from 7.2 to 8.3 cents per kWh. So you can run a 100 watt bulb for 10 hours for about 8.3 cents on your utility bill. It’s actually remarkably inexpensive when you consider the advantage of having a light.
To convert the energy in a gallon of gasoline, we know that the formula for converting BTUs to kWh is:
1 kWh =3412.3 BTU
And so:
1 gallon of gasoline = 111,836 btu = 11,836 / 3412.3 = 32.77 kWh
The government, without ever actually designing a car themselves, have mandated that those who DO manufacture automobiles will achieve a fleet average of 27.5 mpg by 2011.
Barrack Obama has increased those demands to 27.3 mpg. (I know, but we are currently in the Alice and Wonderland world of Barrack-speak, where up is down, down is up, and taxes not paid are actually expenditures out of the pockets of taxpayers. You’ll get used to it after awhile. I think a lot of people actually LIKE it.)
But what kind of mileage do we actually get NOW from internal combustion cars. Well, the latest year where I have all matching figures is 2007. In that year, we had some 255 million cars, and we drove 3,029,822,000,000 miles burning 142,354,380,000 gallons of gasoline = 21.28 mpg
So we can do a kind of a neat thing here, and simply divide the number of kWh in a gallon of gasoline by the number of miles we drive per gallon of gasoline to get the number of kWh per mile or miles per kWh.
1 gallon = 32.77 kWh / 21.28 = 1.54 kWh per mile.
If you like the mileage of a new car better than actual mileage of our existing fleet, we can do it again.
1 gallon = 32.77 kWh / 27.3 = 1.20 kWh per mile.
This is sort of macro. We put gasoline in one end, we get miles out the other, and we know the energy usage per mile in kWh. We don’t care what the efficiency of the engine is, what the losses are in the transmission, or in the wheels. We just have an energy per mile calculation here.
The problem with electric cars is that batteries are not nearly as good at storing energy as gasoline is. With 475 lbs of the very latest Lithium Ion Iron Phospate batteries, comprising 64 cells of 3.6 fully charged volts and 90 amp hours each, I can store about 20.736 kWh of electrical energy. Worse, I can’t really use all of it. I can only use about 80% of that (16.588 kWh) before I begin to damage the batteries.
Worse, there are some losses in putting the electricity into the batteries. I use an advanced power factor charger that is about 95% efficient. So I have to use about 17.461 kWh of electricity from the wall to replace that 16.588 kWh of electricity.
That’s the discouraging equivalent of about 0.5 gallons of gasoline. Yes, the entire range of my car is based on its ability to store the usable energy in one half of a gallon of gasoline.
The good news is that it uses an average of 225 wH of electricity per mile from the batteries, or 236 wH of electricity from the wall per mile. That’s right I get over 4 miles per kWhr.
So let’s compare:
Internal combustion car to be developed in 2011 = 1200 wH per mile.
Electric car built by whiskey drinker in garage in 2008 = 236 wH per mile.
Any way you cut it, the electric car is over five times as efficient as the internal combustion engine automobile. Cost per mile?
1 gallon = $2.00 = 27.3 mpg = 7.32 cents per mile.
1 kWh = $0.082 = 4.24 miles = 1.93 cents per mile.
If you drive the national average of 40 miles per day:
1 day = $2.93 in gasoline or $0.77 for electricity
1 week = $20.51 gasoline or $5.39 for electricity
1 month = $87.90 gasoline or $23.10 for electricity
And that’s using a mythical gasoline car that hasn’t been manufactured yet, as mandated by a government that doesn’t know anything about making cars.
I don’t know anything about making cars either. But you can see the video of mine running.
ALL benefits from electric cars have their basis in this matter of effiiency. Electric drive plants in cars are simply more technically elegant, and MUCH more efficient than internal combustion engines, coal fired engines, wood fired engines, and all other known technologies.
When I step on the accelerator of my Porsche eSpeedster, it makes a sound a bit reminiscent of the Warp Drive sound on Star Trek as the Enterprise accelerated through space.
When I step on the accelerator of my Escalade, it sounds a lot like Uncle Jedd’s truck in The Beverly Hillbillies.
Whose show do you want to be on?
I’d love to tell you that I make them all up. And my detractors would love to tell you that too. Dealing with numerical statistics is a bit like trying to choke a rattlesnake with both of you covered in Wesson Oil – it gets slippery and most people do it badly.
But we traditionally look to goverment studies to compile and present unbiased statistical data. While we all know there are some problems with that assumption, it is a bit better than simply copying what others are saying in forums on the Internet. I call that “typing yourself smart with a keyboard.”
And so in using any number, I like to trace it back to some published, refereed, study subject to public comment from informed individuals. For the purposes of this discussion, I found the U.S. Department of Energy, Energy Information Administration to be the best source regarding energy production, pricing, and consumption. For vehicle, driver, and driving statistics, the best work seems to be done by the U.S. Department of Transportation, National Highway Traffic Safety Administration.
These numbers change! Between the filming of the video, and writing the blog, there are minor inconsistencies in my numbers. Those are generally time zone related. If you talk about 2009 numbers, they are of course different from 2007 numbers or 2008 numbers. When comparing two values, you may only have both for 2007, because one of them isn’t published yet for 2008.
I have gone to some trouble to compile individual links to individual tables in many cases providing you access to the sources as they are published. The gasoline use and pricing, world oil prices, etc. are usually updated monthly or even weekly. In this way, you can go to the table at any time, and get the CURRENT data for YOUR uses.

U.S. Department of Energy – Energy Information Administration
World Crude Oil Prices
Retail Gasoline Prices
Weekly Gas Prices

Daily Gasoline Consumption
Finished barrels per day x 1000 x 42 = gallons

Annual Retail Sales of Electricity to Consumers
Average Retail Price Electricity
Electricity Generation by Fuel Source
Average Monthly Electricity Consumption
Total CO2 Emissions by Energy Source
CO2 Output from Electricity 1.341 lbs per kWh and declining . Coal only – 2.095 lbs per kWh
Reformulated Gasoline – 5.71% ethanol = 111,836 btu
Convert gallons to kWh. 3412.3 btu per kWh
111,836 / 3412.3 = 32.77 kWhr.
National Highway Traffic Safety Administration
2007 Registered Vehicles 255,747,983
2007 Licensed Drivers 205,741,845
2007 Vehicle Miles Travelled 3,029,822,000,000
2007 Daily Gasoline Consumption = 390,012,000 gallons
2007 Average MPG across 255,747,983 vehicles travelling 3,029,822,000,000 miles burning 142,354,380,000 gallons = 21.28 mpg
Average miles driven per driver each year 14,726
Average miles driven per driver per day 40.34.


14 thoughts on “Electric Magic – It’s All About Efficiency”

  1. I viewed the Specifications page, finally. I’d resisted, because I thought it would be too technical for me, but it was surprisingly simple. Although it is still somewhat over my head, I am slowly absorbing more each time I read it.

    I was particularly interested in how many & how varied the other converters were, from all over the world. I hope even more & more visionaries will work in their garages, until “big auto” realizes that EVs are a good investment, like Telcos & other big business discovered the internet.

    Thanks for sharing your vision

  2. I just viewed the video bar! Is YouTube a sponsor of this site? Why else would it include video clips of Susan Boyle, Brit’s crazy fan & that Russian tart?
    Don’t get me wrong, I enjoyed them all, but I just don’t understand why those videos would be on an EV site. Apparently, this is my 1st rodeo! 🙂

  3. I’m not sure either Mark. They are supposed to display videos containing the search terms EV, Electric Car, Electric Vehicle, and Porsche. But they keep slipping in odd ones for no apparent reason.

    Yes, there is a great variety of people doing vehicle conversions. One guy did an electric toilet vehicle. Far too many in my estimation, take rather old vehicles in poor shape to convert. But I guess for a lot of people, its a bit of an experiment and they don’t want to tie too much up in it financially, without knowing for sure they can do it.

    It IS a lot of detail work. But generally, I think anyone can do it. It’s more taking things OUT than putting them in. I have very limited mechanical skills. But we just worked on it a piece at a time until it was done.

    Trouble areas? Mating the motor to the flywheel and transmission should generally be done by a professional machinist shop unless a coupler and adapter are readily available for your model. Fitting the accelerator was a bit of a puzzle.

    And of course how to maximize space for the batteries while maintaining a sane weight distribution is a bit of a rubick’s cube.

    Brian did a great job of integrating an EVISION instrument display with an existing Porsche VDO gage. That’s probably a bit of an adventure.

    But it really isn’t that difficult. It’s more like a puzzle than “working on a car”.


  4. I wrote another blog entry earlier today, but don’t see it here now. Maybe I failed to publish it. It basically asked if you were aware of the Wrightspeed X1 prior to my forwarding the YouTube videos sent to me by my web designer. I just viewed the videos on the video bar detailing the X1 & the other EVs as well as the hybrids.

    This poses the question of why an EV can’t recharge its batteries while it’s rolling. I remember you saying it can’t be done, but if the motor is turning, it should be able to store energy. Then again, to store energy, the EV would need a generator separate from the drive motor.

    I remember you saying that the very 1st cars were electric. For as long as I can remember, growing up we referred to the ICE as a “motor”. Could that be a hold over from those early days of electric cars? Just wondering.

    If I had the $, I’d commission you & Brian to convert my Nissan P/U truck. Of course, I’d need another vehicle to drive in the mean time. The more people you share the eSpeedster with, the more of a ground swell will be generated for EVs.

    By the way, where did you find Brian? He can do just about anything.


  5. Brian found me in 1994. He had drilled a local trader paper into the ground in Colorado. We printed at the same printer so he came by and went to work for Boardwatch Magazine.

    He actually wound up running it for two years after I sold it. He’s worked for me four or five times over the years. Kind of like a bad penny.

    He did a total frame off restoration of a Karman Ghia. He is a lot of things I’m not, but most notably here very precise and organized. He likes to have things just so. I tend to work from the motto “If you are unable to achieve a precision fit with a 3 lb sledge hammer – DON’T FORCE IT.”

    So I mostly research batteries, build circuits, little boxes with instrumentation or contactors or whatever inside NEMA enclosures, do wiring and hookups, program controllers, chargers, etc. find and locate electrical components, and build aluminum battery boxes.

    Brian is very good at “fitting” things. Door handles, accelerator pedals, stereos, the EVISION display in the VDO gage, mounting the charger, and mechanical items such as brakes, wheels, motor adapter and flywheel, etc.

    Together, we make a pretty good team I must say. I can do electrical design and programming, and he can mount it in the car in such a way that it takes up the least room and looks good.

    He primarily drove the concept of having the exterior look like an original 356 speedster with no compromises to the electric drive function.

    An EV can recharge its batteries, but not by generators etc. A motor is a generator. And it is entirely possible to use it as such using the KINETIC ENERGY in the rolling car – regaining some of the energy lost to heat during braking by using the motor as a generator.

    This sounds like a no-brainer. But it really isn’t. To this specific build, I liked the flexibility of an off the shelf DC series wound motor. They don’t do REGEN very easily, and when they do do it, they don’t do it very well.

    You would normally favor an AC induction motor drive system for REGEN. We are using an AC drive in the 2009 Mini Cooper Clubman conversion, and indeed we will do a BIT of regen.

    Regen itself is not precisely the free gift it is presented as. To understand this, you almost have to drive an electric car for awhile.

    When you remove your foot from the accelerator of an electric car, it doesn’t slow down at all in the way an ICE vehicle does. If you are going downhill, you may even continue to accelerate. This is disconcerting at first, but you quickly learn to like it.

    It means you can “coast” in a lot of situations for a half mile or more without using ANY energy. And often you can coast downhill and use that buildup to “slingshot” up the next. After awhile, you start playing this game with it, and can get pretty good at it. If I quite driving the Porsche like a Porsche, and start doing this, I can get well over 100 miles out of a charge in town.

    REGEN recaptures this kinetic energy of the cars forward motion. But of course it slows the car. In most regens, when you take your foot off the accelerator, regen kicks in.

    I think you use the energy more efficiently to continue forward. And the conversion back to electricity, and then the reconversion to chemically charge the batteries, is less efficient use of this energy than simply rolling.

    So we will have regen on the cooper, but it will be only activated by a BRAKE switch. And it will be fully adjustable. I’ll have a little knob where I can dial in what I want, and when I first step on the brake, that amount of regen will kick in. Further pressure on the pedal will also of course deploy the conventional brakes.

    In this way, I can use the kinetic energy as I like, to coast in some instances, or to charge in others.


  6. Jack, This is all so facinating. The adjustable regen feature on the Cooper sounds very advanced & innovative.

    It’s clear to me now that driving an EV is quite a bit different than driving an ICE car, but the different driving style would become second nature with some seat time behind the wheel. Knowing when to coast,conserving energy & when to deploy the regen, is the challenge, but seems quite doable with practice.

    What are your thoughts on the YouTube video showing how dead batteries can be restored to full or greater power? This sounds promising regarding cost management & lower environmental impact.

    I saw on the web cam that Joe S. & the Mr. Greenthumb video crew were on site. Are they shooting video for you or just using your location?

  7. They were shooting some segments for Cable Operators that Jim Riley is putting together.

    The YouTube on regenerating batteries is a bit of a dead end for me. It is about restoring lead acid batteries.

    Even at the turn of the LAST century, lead acid cells had been displaced by the Edison Nickel Oxide/Iron batteries, an option on the 1914 Detroit Electric.

    The ubiquitous and inexpensive lead acid battery has been part of the problem, never part of the solution. Because they are made in the brazillions, lead acid batteries have huge economies of scale. So anyone comparing the cost of small volume advanced chamistry batteries to lead acid are always struck by the difference in cost.

    It’s a battery powered car. Better batteries, better power. $10K for batteries? Ouch. But that’s what they cost right now.

    I think they’ll comde down. But they will never reach the cost of lead acid batteries.

    I plan to use old lead acid batteries to build a quick charge power supply for my electric cars. Basically, I’ll charge them slowly, and use the bank to charge the electric car quickly. Maybe put solar panels into the mix at some point.

    Jack Rickard

  8. I’ve been reading all about Nikola Tesla in Wikipedia.
    Check out my friends @ http://www.48statedrive.blogspot.com. I took their picture for the article in the Mercedes-Benz Club of America magazine, The Star. They are a father & daughter who drove their ’68 250Se through all 48 states last July from Cape. His parents, who’ve both died, before the daughter knew them, bought the Benz used in ’69 & left it to him. He’s driven it ever since.

  9. Tesla was a visionary genius. If he hadn’t been so eccentric, he would have achieved much more credibility. He should have hired a PR firm!

    He was postumously officially credited with the invention of the telephone. He despised his former boss, T.A. Edison for his insistance that DC was the way, not AC. Of course, we now know, like Tesla knew then that AC was the future.

    I am amazed by what I read about Tesla & before yesterday, I never knew of him. I truly hope that before I die at age 100 riding my bike at 50 mph downhill, that I, along with the rest of the world, will own an EV.

    I have a suggestion or 2 about how to improve the photos of the eSpeedster on this web site, if you ever want to reshoot them. Plus, I want to take some photos of the eSpeedster.

    I’ll drop by soon to see how the Mini is coming along.


  10. I’ve been reading on Wikipedia about the Brazilian aviation pioneer, Alberto Santos-Dumont. His family moved to Paris in the 1890s, where, first as a boy, he took up dirigibles, both free floating & steerable.

    He, then began building heavier than air aircraft. He preceded the Wright Bros. in the 1st public airplane flight, by a few years. Apparently, France was a hotbed of aviation innovation.

  11. Hi Jack, Just finished watching your “Part One” at Autoblog Green… Brilliant!

    Although I would have used a Cobra replica, instead of a Speedster… not because a Speedster isn’t cool, but because mostly guys of MY generation love the 356 (I graduated from high school in 1972) whereas my kids (the ones who help me with all my car projects) love Shelby Cobras and Lamborhini Countach and the new 911’s… so, I’d use a more contemporary design, to motivate my adult boys… all of whom love working on cars (Sam, my next-to-youngest, owned a Boxster, and Joe, my second-oldest, owned a turbo Supra).

    Well, best wishes… and, hey… what about a four-wheel-drive electric? We all drive Subarus, up here in the snowy mountains!

    Regards, Jeff Zekas, Susanville, California

  12. We’ve looked seriously at a 911 or Boxster. I think both would be good examples of a more “modern” technology and get into the very interesting issues of simulating an air conditioning compressor, vacuum pump for power brakes, water heater for heat, etc.

    Instead, we’re going to do a 2009 Mini Cooper Clubman next. But a modern Porsche is definitely on the table for a future project.

    The father/son thing would just be ideal. My own son has no interest in cars or airplanes (go figure) but I’ve seen a number of these projects really get to be a gig for father/son teams.

    Jack Rickard

  13. Pingback: Performance or Environment? - EVTV LLC

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