Air Cars vs. Electric Cars vs. Hybrids - Which are Greener?
An ‘air car’ sure sounds clean. A car that runs on air? What’s cleaner than that? But of course it’s not quite that simple.
The world’s first commercial air car is currently being produced by India’s largest automaker, Tata Motors, who is licensing the technology from European-based company MDI. A compressed-air car uses the force of super-compressed air to move the engine’s pistons up and down, as opposed to explosions produced from injecting a small amount of fuel. At higher speeds the engine will burn a small amount of fuel to create more compressed air, sort of like how a plug-in hybrid like the Chevy Volt produces on-the-fly electricity. The hybrid air-car setup should be able use any number of fuels, including gasoline, propane, or ethanol.
So now that we’ve established how the Air Car will work, how green is it?
Well, there are CO2 emissions associated with both the electricity required to power the air compressor, and the liquid fuel required to create more compressed air on-the-fly.
A comprehensive analysis of these emissions is available in the Huddler Air Car Introduction Wiki. What it boils down to is that on average, the ZPM Air Car produces 0.176 lbs of CO2 per mile, using the average US power grid mix. If you’re getting your electricity from a greener utility like California’s Pacific Gas & Electric (PG&E), this brings the total emissions down to 0.155 lbs/mile.
In comparison, the second generation Prius emits 0.34 lbs/mile, so the ZPM Air Car does indeed produce roughly half the CO2 emissions of the Prius, as the company claims.
The Tesla Roadster creates 0.24 lbs/mile of CO2 for the average US power grid mix, and 0.093 lbs/mile for the PG&E mix. The Aptera typ-1e creates 0.114 lbs/mile of CO2 for the average US power grid mix, and 0.044 lbs/mile for the PG&E mix. So in most instances, the ZPM will produce lower emissions than the Tesla, but not when the power comes from low emissions sources like PG&E’s. The Aptera typ-1e produces the lowest emissions by far.
The moral of the story is that the Air Car does quite well in terms of emissions. It will also supposedly seat 6 with a low price tag at around $17,800, so the Air Car could be an affordable and green alternative to fully electric cars.
Posts Related to the Air Car and Electric Cars
- An Air Car You Could See in 2009: ZPM’s 106 MPG Compressed-Air Hybrid
- Germany Gets Smart with Electric Car Charging Stations
- Alaska Police Pull Over Solar Powered Car, Think it’s a UFO
- Nissan to Launch Solar-Powered Electric Car
- “Producible” Chrysler Plug-In Hybrid: 0-60 in 4 Seconds
- Nanotechnology Increases Lithium-Ion Battery Storage Capacity 10 Times Over
- Tata to Launch Electric Car in Norway Within a Year
Photo Credit: Zero Pollution Motors
A hybrid can never be superior in terms of emissions or efficiency to an electric (unless the grid somehow became less efficient than an ICE). The only reason for hybrids is their extended range vs. today’s (but not necessarily tomorrow’s) battery chemistries.
Air cars have crap performance, and that’ll always have crap performance, owing to the low power density of compressed air.
But perhaps the most important question isn’t about the relative performance of these cars today, it’s about the extensibility of the architecture. With electric cars, you can instantly change the power source for millions of vehicles by upgrading a few dozen power plants. Compressed air, like liquid fuels, is a transportation crap-fest. Grid losses are tame by comparison. And plug-in is a helluvalot more convenient for motorists than fueling up. Hopefully it will also encourage us to stop parking on our f’ing streets.
I’m pretty skeptical of the loveliness sound of the “air-car”. The thing is, a gasoline engine pressurizes the cylinders on the go, while the “air-car” pressurizes them all effectively in advance. So there is no fundamental energy savings going on here, you are merely changing where you do the work.
You could compare this to running a car on batteries that run an air compressor that push cylinders. So in effect, pressurized air is just a mechanical form of ‘battery’. It’s a gaseuous form of a wind up spring powered car. Compression will increase molecular heat/temperature which will tend to dissapate and therefore be lossy. So it can’t be terribly efficient either.
So hey, maybe this totally novel technology can be made to work. Will it be better than the tech that’s been worked on and refined for decades? Investors, hang on to your wallets.
The air car sounded like the car of the future…that is until the French were forced to comply with U.S. car crash standards by increasing the weight of the car with more metal, then having to add a combustion engine to it in order to haul all that extra new weight.
I think the air car would work better in the U.S. as a legally lighter, 3-wheeled air motorcycle.
The linked article is ridiculous. The overwhelming majority of the range of the air car comes from the gasoline, not the air. The simple facts are that air compressors are extremely inefficient (I have no clue where the article there gets off with the unreferenced claim that they’re 60% efficient — they’re generally 10-20% efficient), and compressed air has extremely poor energy density. MDI is largely a vaporware company anyways that’s been “spinning their wheels” for over a decade, with many specious claims. The founder even distorts his own resume. For example, Negre claims that he was responsible for ““development of a 3.5-liter W-12 engine for Formula One toward the end of the ’80s.”” No such engine was ever raced in F1 races.
How about a cost/mile comparison for these vehicles?
Right, I know I may sound like the perfect candidate for a pro green public stoning for starting my post this way, but:
I am not TRULY concerned about whether a compressed air car is more green than an electric one.
I applaud the concept of both, however, I believe that any of the new concepts that needs any amount of petrol (Petrol is what we Britts call gasoline) has failed. Yes, I understand that the ZPM CAN run on ethanol, but if the ZPM is a hit in Europe and the US, I’m sure that petrol will stll be the fuel of choice, since it will still be the most available.
When the new Lithium bateries with the nano tech applied to it are installed into electric cars, a 200 mile Tesla may become capable of 2000 miles. Or the extra capacity could be used to power larger electric vehicles.
Already producing faster & more powerfull vehicles (&lets face it, when it comes to cars people want power) the electric car stands high above the compressed air vehicles.
As for Bio fuels I belive that we should take this extra crop growing capabiltiy and feed the people who need it the most. Firstly within our own counties, secondly we give to our allies, and then to our enemies. (and dont forget, as babies we learned to love whoever fed us. Also, feeding your enemies makes their hatred towards you harder to justify. Why else would our countries deliver food aid to the inhabitants of the countries we war with.)
I belive in killing two birds with one stone and if you can get even more than that, then call some friends and have a party.
If the US & Europe switched to cars that required no fuel produced from oil, then that would mean much less dependance on foreign oil.
This would mean that the tension with the arabs etc would be aleviated and the price of oil would not dictate the rates of inflation, thereby reducing wars and strengthening the economies of those involved with the change over.
An optimistic view? of course it is and that’s exactly why its very unlikely to ever happen.
Ps. If you like my writing and would like to pay me per article, then please contact me.
Can someone tell me how many lbs/mile of CO2 something like a full size Chevy 4×4 Suburban releases, or even your standard family sedan….just for comparison?
These are the vehicles I see most on the road, and would like to know how hybrids/electrics/air vehicles that you report on compare to “the norm”.
I like the idea of the air car but compress air trains are more likely take off since you can big engouh tanks to go 1000 miles.
Matt - a cost analysis is available in the Huddler link.
Travis - your average sedan emits about 1.5 times more CO2 than a Prius, which emits 2 times more CO2 than the air car (which is roughly on par with EVs). The largest SUVs emit 3-4 times more CO2 than the Prius.
This is a bit disingenuous. A gasoline powered vehicle MUST produce emissions. It’s an inherent property of the internal combustion engine. An air car uses electricity. Granted, there are ways to produce electricity that produce emissions, but there are plenty of others that don’t - wind, solar power, hydro-electric power and wave power to name some of the top contenders. Is it a stretch to believe that someone who’s committed enough to lowering their energy footprint to buy and drive an air car would also be likely to avail themselves of a source of electricity that’s equally environmentally friendly?