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A gallon of gas weighs about 6.3 pounds and produces roughly 35 kilowatt hours of energy. That’s enough to burn a 100-watt light bulb continuously for more than two weeks. A lead-acid battery could do the same thing without needing a recharge—if it were the size of a desk and weighed a ton. Energy density is the point. We just haven’t come up with a fuel or a device that will safely and economically offer the same calorific value in such a small space as an automobile’s gasoline tank. Compressed natural gas (CNG) and liquefied natural gas (LNG) intrigue us, but the problems of storing them (or hydrogen) in a car in sufficient quantity to approach gasoline’s range and performance continues to be a sticking point. We always come back to density.

Oddly, nothing better illustrates the overall efficacy of gasoline than an electric car. In 1900, when electric, gasoline, and steam cars were vying with one another, an article in American Monthly Review of Reviews pointed out that the gas car had “developed more all-round good qualities than any other carriage,” not the least of which was that “it carries gasoline enough for a 70-mile journey and nearly any country store can replenish the supply.” It was true back then and it remains true today. The standard to which electric cars aspire—for speed, flexibility of operation, and range—is the gasoline standard.

http://www.aei.org/publication/why-gasoline-is-still-king/
 

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True facts, which is why the Volt concept is and will always be the best of both worlds. Volt drivers go for weeks without burning a drop, then hit the road for 12 hour drive without a second thought.
 

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That article is almost 9 years old (and still relevant).
 

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A gallon of gas weighs about 6.3 pounds and produces roughly 35 kilowatt hours of energy. That’s enough to burn a 100-watt light bulb continuously for more than two weeks. A lead-acid battery could do the same thing without needing a recharge—if it were the size of a desk and weighed a ton. Energy density is the point. We just haven’t come up with a fuel or a device that will safely and economically offer the same calorific value in such a small space as an automobile’s gasoline tank. Compressed natural gas (CNG) and liquefied natural gas (LNG) intrigue us, but the problems of storing them (or hydrogen) in a car in sufficient quantity to approach gasoline’s range and performance continues to be a sticking point. We always come back to density.

Oddly, nothing better illustrates the overall efficacy of gasoline than an electric car. In 1900, when electric, gasoline, and steam cars were vying with one another, an article in American Monthly Review of Reviews pointed out that the gas car had “developed more all-round good qualities than any other carriage,” not the least of which was that “it carries gasoline enough for a 70-mile journey and nearly any country store can replenish the supply.” It was true back then and it remains true today. The standard to which electric cars aspire—for speed, flexibility of operation, and range—is the gasoline standard.

http://www.aei.org/publication/why-gasoline-is-still-king/
EPA uses 33.7kWh/gal for mpge.

Anyway, it's not really gasoline's energy density that's the real challenge. It's plug-in cost and diesel's energy density.

Gasoline is on average 10% ethanol already. Given ethanol is 70% of the energy density of gasoline, then if you can electrify 92.8% of current gasoline miles you'd be able to supply E100 with no additional ethanol production capacity. Given that a BEV200 would give you over 80% of household miles without _any_ DCFC or destination charging, and given that the proportion of trips still reduces by distance, and given that an EREV could also cover a high proportion of miles, as well as raising ICE efficiency through hybridization then technically, it's just a cost challenge. Well, of course there's politics, but the political argument is a pragmatic one, and the lower plug-in costs go, the weaker the pragmatic argument would become.

It's diesel that's the really tough thing to replace. That's the stuff used for heavy commercial mileage and in business, time is money. While some miles could easily be replaced by cheap plug-ins, heavy freight fuel use would be a much bigger challenge.
 

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This is why I have a Volt. It covers my daily driving needs as an EV and then allows me to hit the road without worrying about refueling. I won't even consider a pure EV until the infrastructure, range (almost there), and refueling speeds are in place.
 

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Gas may have 35kw per US gal but only a quarter is used by an IC engine but with an electric motor 95% of it would be used so a 16kw battery is the equivalent of 64kw of gas approx. 2 US gals. in metric about 12kw per Kilogram of gas so once batteries hit approx. 3.5kw per kg then battery would be same weight as the tank of gas it replaces. Lithium air has in theory approx. 10kw/kg so may meet this goal, if so gas is dead. With fast charging to 80% and high power DC chargers, filling a battery will become closer to the refuelling with gas times.
 

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A gallon of gas weighs about 6.3 pounds and produces roughly 35 kilowatt hours of energy. That’s enough to burn a 100-watt light bulb continuously for more than two weeks. A lead-acid battery could do the same thing without needing a recharge—if it were the size of a desk and weighed a ton. Energy density is the point. We just haven’t come up with a fuel or a device that will safely and economically offer the same calorific value in such a small space as an automobile’s gasoline tank. Compressed natural gas (CNG) and liquefied natural gas (LNG) intrigue us, but the problems of storing them (or hydrogen) in a car in sufficient quantity to approach gasoline’s range and performance continues to be a sticking point. We always come back to density.

Oddly, nothing better illustrates the overall efficacy of gasoline than an electric car. In 1900, when electric, gasoline, and steam cars were vying with one another, an article in American Monthly Review of Reviews pointed out that the gas car had “developed more all-round good qualities than any other carriage,” not the least of which was that “it carries gasoline enough for a 70-mile journey and nearly any country store can replenish the supply.” It was true back then and it remains true today. The standard to which electric cars aspire—for speed, flexibility of operation, and range—is the gasoline standard.

http://www.aei.org/publication/why-gasoline-is-still-king/
I believe that focussing solely on the energy density of the fuel is unwise.

Electric motors can weigh a lot less for the same power output, and are of course much more efficient, needing less total energy to cover the distance. The characteristics of an electric motor eliminate the need for a complicated and heavy transmission. and reduce the need for heavy and high drag radiators, etc.

All put together, it means an electric car can probably be lighter (and cheaper) than an ICE car with typical 4-500 mile ranges even if the battery is an order of magnitude heavier (which is still well beyond batteries in EVs today.)
 

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Our 2016 Volt is the best of both worlds, gas when you want it and electric when you want it. My wife and I just returned from vacation up in the Bend Oregon area. Left our home at sea level and the highest pass was over 4,800 feet. We stayed 3 nights and our campsite / cabin allowed us free electric car charging on 120 Volt. Had nearly 600 miles when we returned home and our overall gas only mpg's was impressive for our loaded Volt, which was well over 47 mpg climbing those mountains. The 150 miles or so electric, free charging of course, was just an extra bonus. Even our 2010 Prius would be hard pressed to have achieved over 47 calculated mpg's under the same conditions.
 

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I believe that focussing solely on the energy density of the fuel is unwise.

Electric motors can weigh a lot less for the same power output, and are of course much more efficient, needing less total energy to cover the distance. The characteristics of an electric motor eliminate the need for a complicated and heavy transmission. and reduce the need for heavy and high drag radiators, etc.

All put together, it means an electric car can probably be lighter (and cheaper) than an ICE car with typical 4-500 mile ranges even if the battery is an order of magnitude heavier (which is still well beyond batteries in EVs today.)
I would point out that the window sticker on my 2012 Volt gives it a 379 mile electric/electric-like range, the first 35 of which come from grid electricity pre-stored in the battery, and then from "as needed" gas-generated electricity converted from the on-board gas supply into ~10 kWh of electric power for each gallon converted (which GM calls "electric-like" driving). Clutching the generator to the ring gear under appropriate conditions in Extended Range mode increases overall efficiency, but at lower speeds, the Gen 1 Volt remains an "electric" car. My Volt is thus quite capable of traveling 379 miles non-stop in one-motor mode propelled by an electric motor using electric fuel, and even from coast to coast on electricity at ICE car refueling speeds.

One gallon of gas may be energy intensive, but is it more efficient to burn gas as a propulsion fuel, or to transform gas into electrical energy by using it to fuel a generator to power an electric motor?
 

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I would point out that the window sticker on my 2012 Volt gives it a 379 mile electric/electric-like range, the first 35 of which come from grid electricity pre-stored in the battery, and then from "as needed" gas-generated electricity converted from the on-board gas supply into ~10 kWh of electric power for each gallon converted (which GM calls "electric-like" driving). Clutching the generator to the ring gear under appropriate conditions in Extended Range mode increases overall efficiency, but at lower speeds, the Gen 1 Volt remains an "electric" car. My Volt is thus quite capable of traveling 379 miles non-stop in one-motor mode propelled by an electric motor using electric fuel, and even from coast to coast on electricity at ICE car refueling speeds.

One gallon of gas may be energy intensive, but is it more efficient to burn gas as a propulsion fuel, or to transform gas into electrical energy by using it to fuel a generator to power an electric motor?
Depends on the generator.

The question itself is something of a strawman, since it ignores the reality that many other ways of getting electricity exist and are commercially viable right now and assumes the fuel must be burned.

Going with the paradigm of the question, though, you're now in a realm of dueling efficiencies.

A large stationary generator is substantially more efficient than any car engine, even one as cutting edge as the Volt's - many modern plants are combined cycle, where the exhaust is cooled and the heat from it used to turn another turbine; these can exceed 60% thermal efficiency in ideal conditions (which as defined includes the loss going from mechanical to electrical already.)

On the other hand, the mechanical transmission of power to the road is very efficient, while the electrical version has losses from the grid transmission, from the battery cycling, and then from the motor spinning - all pretty efficient as processes go, but not the equal of a well designed transmission.
 

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All put together, it means an electric car can probably be lighter (and cheaper) than an ICE car with typical 4-500 mile ranges even if the battery is an order of magnitude heavier (which is still well beyond batteries in EVs today.)
So trying to think of a car where I could compare curb weights.....

2014 Chevy Spark curb weight - 2368 lbs
2014 Chevy Spark EV curb weight - 3000 lbs
 

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So trying to think of a car where I could compare curb weights.....

2014 Chevy Spark curb weight - 2368 lbs
2014 Chevy Spark EV curb weight - 3000 lbs
There's not a lot of wiggle room in the Spark. The vehicle frame and safety cage structure weighs in at over 1500 lbs in the Spark. Also, as everyone knows, batteries are currently very heavy. The question you need to ask, assuming both are equipped the same except for the drivetrain, is which is more efficient. I suspect the EV version will win hands down.
 

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There's not a lot of wiggle room in the Spark. The vehicle frame and safety cage structure weighs in at over 1500 lbs in the Spark. Also, as everyone knows, batteries are currently very heavy. The question you need to ask, assuming both are equipped the same except for the drivetrain, is which is more efficient. I suspect the EV version will win hands down.
How big would the Spark battery need to be to have the same range as the ICE version (as if it would fit in the car) and then what would that weigh?

The EV Spark weighs 632 pounds more and has a fraction of the range.
 

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all long range EVs consume many times the weight of a traditional drive train until you approach large engines. Its hard to come up with eight hundred if not more pounds that a modern battery pack has, one that gets 250 miles on a good day.

As for charging times, people vastly and I mean vastly underestimate the power requirements to charge a large battery quickly. You have both the ability to deliver the amount of power actually needed for the replenishment times desired and the ability of the pack to receive it and manage the heat produced. None of which is going to happen fast. you might get a few manufacturer demonstrators but it won't be meaningful.

full on battery is fine for local transportation, extended range concepts fill the needs for all other usage patterns
 

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all long range EVs consume many times the weight of a traditional drive train until you approach large engines. Its hard to come up with eight hundred if not more pounds that a modern battery pack has, one that gets 250 miles on a good day.

As for charging times, people vastly and I mean vastly underestimate the power requirements to charge a large battery quickly. You have both the ability to deliver the amount of power actually needed for the replenishment times desired and the ability of the pack to receive it and manage the heat produced. None of which is going to happen fast. you might get a few manufacturer demonstrators but it won't be meaningful.

full on battery is fine for local transportation, extended range concepts fill the needs for all other usage patterns
Agreed. I had the discussion with my wife over the weekend about the amount of power it takes to overnight charge a Tesla Model S 100D. Your typical house in the US is physically limited to the amount of power it can supply. Much more than an 100KWh battery and you start bumping up against the supply capabilities of a house. Remember that supply also runs all the other electronics in the home, including the Air Conditioner compressor, the HVAC blower (even with a natural gas furnace), electric water heaters, most stoves (some homes have gas stoves but most are electric), plus all the other stuff running in the house.
 

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Very True regarding energy density of Gasoline.
But some things to remember. An ICE is only ~1/3 effiecient, 2/3 lost as heat. So you actually need 3 gallons of gas to realize all the energy contained in a single gallon.
Gasoline requires an ICE engine, and transmission, and exhaust system. I suspect all these supportive components weigh much less than the electric motor in Electric drive train. All these components don't totally make up for the Wgt difference between battery verses gasoline tank, but they close the gap somewhat.
Another consideration. To get that gallon of gasoline, land must be secured, drilled, crude oil transported, crude oil refined (not the cleanest process, as I wouldn't want my well water to come from under a refinery, the refinery process also consumes a tremendous amount of energy, the refined product then transported again to consumer. So if you were to back out all the energy that goes into a gallon of gasoline, and getting it to the customer that gallon of gasoline looks a little less energy dense.
All that said your point is well taken, and there will be a place for gasoline for long time, due it's energy density. BUT as renewable become cheaper, and batteries close the gap in price and energy density gasoline will play a smaller roll.
My personal example is I have CMAX energi. Probably 1/4 of my trips are less than 5 miles. (trip to store, ect.) These trips are when ICE car is absolutely least efficient with cold engine around town drive. This is when all Electric drive most efficient. 1/2 trips are less than 20 miles... Electric more efficient. I happen to have solar panels so 75% of my driving is on sunshine. Maybe 1/4 of trips are 20-100 miles these use ICE and the value of Gasoline energy density is fully realized. At this point Plug in hybrids don't have a lot of negative compromises. On the positive it takes me about 5 seconds to plug in once I pull into garage. I visit a gas station every 6 weeks or so. My car will likely never need new brake pads or rotors because 90% of my breaking is recaptured as energy for the battery as opposed to friction braking, My fuel cost per mile is probably about .02 cents / mile, as opposed to .10 cents. Electricity has always been cheaper than gasoline as far as miles per dollar driving, so I use EV driving as much as possible. However plug in hybrids give maximum flexibility should on the off chance gasoline ever goes to .75 cents a gallon for a finite amount of time I may make sense to choose the EV Later button in my CMAX energy and drive exclusively on gasoline until the price per gallon increases greater than $1. It is good to have options.
 

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Another consideration. To get that gallon of gasoline, land must be secured, drilled, crude oil transported, crude oil refined (not the cleanest process, as I wouldn't want my well water to come from under a refinery, the refinery process also consumes a tremendous amount of energy, the refined product then transported again to consumer. So if you were to back out all the energy that goes into a gallon of gasoline, and getting it to the customer that gallon of gasoline looks a little less energy dense.
You can look at electricity that way too, considering that a larger portion each year of electricity supply is from natgas generators. Around these parts natgas generation is our #1 source.
 

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So trying to think of a car where I could compare curb weights.....

2014 Chevy Spark curb weight - 2368 lbs
2014 Chevy Spark EV curb weight - 3000 lbs
I'm not sure where you think you're going with this. There's no question or argument that EVs are heavier than comparable ICE cars right now; my only point was that they don't have to get batteries anywhere close to as light as gasoline before the car as a whole will be comparable.

I'd at least use a platform designed from the beginning for multiple power options in your comparison if I misunderstood and you still have a point to make, though:

Ioniq Hybrid: 2996-3116
Ioniq Electric: 3164-3285

Golf:2963-3023
GTI:3031
Golf R:3340?
E-Golf: 3380
GTE: 3360

Of course, none of these EVs have anything like comparable ranges - but the best current lithium packs are something like fourteen pounds per kWh, while gas is almost six kWh per pound. My suggested crossover point would be around two pounds per kWh, batteries weighing 14% of what they do now...
 

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I'm not sure where you think you're going with this.........

......but the best current lithium packs are something like fourteen pounds per kWh, while gas is almost six kWh per pound. My suggested crossover point would be around two pounds per kWh, batteries weighing 14% of what they do now...
Energy-to-weight ratio of the package as a whole.

Electrons weigh just about nothing. The 'fuel' cost is comparable depending on where you live. The container is the problem.

As a whole package, the electric motor/transmission being lighter (etcetera) doesn't offset the battery weight. You can't just look at the weight of the drive system sans the battery.

Take every discussion about energy density and throw them at a car buyer. His/her first question is "How far on a fill-up can this car go?" The next question might be "How long does it take to fill it up?" No EV can stand up to these questions, no matter how much convoluted logic you throw at them.
 

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I don't see weight being the real issue unless we are talking about powering an airplane. The extra weight in a Tesla Model S or X is not a problem. They have good range and are widely recognized as good vehicles even among the ICE crowd. They can carry the weight and are powerful enough to move the weight quickly, so weight is not the limiting factor. They are also known as very roomy vehicles, so battery pack volume is not the limiting factor if properly designed. The main issue with those vehicles is the high price. So it really comes down to manufacturing cost being the big advantage of ICE over BEV. And as we are seeing with the Model 3 and Bolt, the cost issue is improving. Obviously there are some other issues as well such as charge time and access, but I think it is arguable that cost is the primary factor, at least for personal transportation.
 
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