EV Powertrains To Be Nearly As Energy Dense As ICE By 2045

JUN 19 2016 BY MARK KANE 22

Tesla Model S Drivetrain

Tesla Model S Drivetrain

Argonne National Laboratory (ANL) has published an article “Comparing the Powertrain Energy Densities of Electric and Gasoline Vehicles” in a SAE Technical Paper which compares all-electric and gas power train energy density.

As one might expect, liquid fuel is found to store a tremendous amount of energy in each unit of weight, but interestingly most of the energy is still wasted in the end.

Assuming improvements in battery technology, as well as in electric motors/power electronics, ANL’s team expects that by 2045 BEVs with 300 miles of range (and single speed-transmissions) will have power train energy density on par with petrol vehicles (also including some improvements like start-stop systems).

“By 2045, BEV 300s will be comparable to conventional vehicles in terms of the energy spent at the wheel per kg of the powertrain mass.”16


“The energy density and power density comparison of conventional fuels and batteries is often mentioned as an advantage of conventional vehicles over electric vehicles.

Such an analysis often shows that the batteries are at least an order of magnitude behind fuels like gasoline. However this incomplete analysis ignores the impact of powertrain efficiency and mass of the powertrain itself.

When we compare the potential of battery electric vehicles (BEVs) as an alternative for conventional vehicles, it is important to include the energy in the fuel and their storage as well as the eventual conversion to mechanical energy.

For instance, useful work expected out of a conventional vehicle as well as a BEV is the same (to drive 300 miles with a payload of about 300 lb). However, the test weight of a Conventional vehicle and BEV will differ on the basis of what is needed to convert their respective stored energy to mechanical energy. This study provides a fair comparison of technologies to report the real status of battery electric vehicles when compared to their gasoline-powered competitors.”

source: Comparing the Powertrain Energy Densities of Electric and Gasoline Vehicles) via Green Car Congress

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22 Comments on "EV Powertrains To Be Nearly As Energy Dense As ICE By 2045"

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EV’s nearly as energy dense by 2045 ?
How about EV’s more energy dense by 2017 !!!
The graph is nonsense and ANL is obviously not aware that Phinergy has already demonstrated an Aluminum-air battery that has 1,000 miles – 1,600 km of range on 110 lbs – 50 kg of Aluminum and are working with ALCOA to commercialize it by 2017.

Working to commercialize isn’t the same as a sure thing. Many, MANY other promising false starts have already shown why we shouldn’t skin the bear until it’s been shot. 🙂

I think that the technology you are referring to is more akin to a fuel cell than a battery, and could be promising as range extender.

Phinergy demoed it as a range extender. It’s a ‘primary’ battery that’s ‘mechanically’ rechargeable by replacing the aluminum plates. More importantly, it gets oxygen from the air (like a fuel cell) rather than storing O2 in the cell like a rechargeable battery.

Have you not read Phinergy’s white papers?

Alu-air (or other metal-air) batteries, Phinergy’s or others in the pipeline, aren’t directly rechargeable by electricity. The reaction which releases energy from the battery consumes the battery plates, which then need to be replaced by new ones.

As others commented, this type of battery is therefore suitable for a range extender battery for long trips, but not for daily use.
I suspect that the window of opportunity for such dual-battery drivetrains is very narrow. Beyond being a bit more complex (managing the switchover between batteries, and needing to monitor both), there’s the entire issue of a network of plate-replacement stations — this requires standardization of plates to be economically viable.

If they don’t demonstrate an commercially-manufacturable system within 6-12 months, I personally suspect the window of opportunity will close for BEV car applications — battery tech is improving, both density-wise and cost-wise, too quickly.
They may still make sense for long distance vehicles like trucks etc.

2045? Predicting what will happen 30 years down the line is like psychic reading: nonsense. This is especially true with human endeavors.

But if we’re talking about 30 year nonsense, I predict everyone will drive ethanol FCV and pay more than they do with gasoline and be really happy that they MUST drink the tailpipe water which was mandated by the government. Many will combine fuel with “exhaust”.

I agree that predicting almost anything so far into the future is difficult to take seriously. Change happens ever faster, so it’s a bit like guessing what the state of tech would be now back in 1916…

That said, I think it’s an interesting study/analysis for two reasons: First, it makes a very good point that the proper way to compare is to measure total drivetrain AND fuel mass versus useful energy. Including all the waste becomes misleading when some of the things being compared are twenty times as wasteful as others..! Second, it shows what must happen for BEVs to be on par with ICE, and this is probably near the truth (ICE is unlikely to ever become much more efficient than it is) regardless of the time it’ll take to get there.

What is the proper way to pronounce the acronym – “ANL” ???

Any decent person takes the time to say the letters, and not try to “pronounce” any acronym, let alone this one…

The decent people who SCUBA dive or work at NASA might disagree with you. 😉

SI means Spark Ignition.

DM means two speed transmission (it doesn’t say why).

Fixed means a single speed transmission.

Wheel Out means output energy measured at the wheel.

Thank you for explaining these codes to the less educated, Ambulator! It now makes some sense.

I’m guessing DM means dual motors.
Because they have shown better efficiency.
And if, as I thought it should, their final ration gearing is different, you do have two speed motoring without ever shifting gear.

Nice article Mark Kane, now with source! Keep it up 🙂

Its the elephant view of the electric car: Oh, the battery is heavyer than equivalent gas. Oh, the battery is bigger than equivalent gas. Oh, the battery is costler than equivalent gas.

The article is good in that it points out that due to the better efficiencies of EV drive, 1:1 weight/size/cost with gas is not the target. Cost of gas already passed in EVs favor. Weight is an arbitrary target that matters more for airplanes. Nobody appears to care about size (is anyone complaining the Model S is too big?). Everyone is complaining about cost.

Some people do complain that the Model S is too big, although not near the number who complain it’s too expensive.

Price is everything. Assuming no supply limitation and a $35K price point from the start, there would be millions of Model S on the roads by now, if not tens of millions.

The problem with comparing apples and oranges is, they are not the same. And neither are IC drive trains and BE drive trains. There is a big difference between a top of the line V-12 or a simple three in line engine. But a top of the line 60kWh battery pack is exactly the same as the most simple 60kWh battery pack.

If you compare the drive trains of a Mercedes S-class with a Tesla Model S, the Model S wins on every measure. But Tesla’s technology is just getting on par with the E-class. Next year Tesla is going to compete with the Mercedes C-class. And initially the C-class will score better on some measures. The Mercedes B-class is still out of reach. And so are the Mercedes A-class, the Daimler Smart, and the VW e-UP.

So what do we know about the energy density comparison between an IC drive train and a BE drive train?

It depends!

This study makes no sense… For me the battery is part of the powertrain. The same a a fuel tank is part of the powertrain.

A 100 miles BEV should be more energy dense than an 300 miles BEV since a 100 mile battery is far lighter than a 300 mile battery. Therefore a 100 miles BEV number should be less than the 300 mile BEV number.

What do they smoke to expect a 100 mile BEV to be heavier than a 300 mile BEV????

As I understand it the energy density of the bev100 is lower because the fixed mass of the motor and electronics makes a larger proportion of the total propulsion system mass. So the battery, the actual energy supplier is a lower percentage.
In the bev300, the motor and electronics keeps the same mass but the battery increase, so the actual energy supplier is a higher percentage. Hence bev300 having a higher energy density than a bev100.

Ahhh, now i get it. Thanks.

I will be too old to drive by 2045…