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?
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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.
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Photo Credit: Zero Pollution Motors
Scott - I’m not sure why you think the article is disingenuous. The calculation was simply based on the Average US power grid mix, and also on a more environmentally friendly mix. Certainly emissions can be reduced further by getting electricity solely from renewable sources, but I think that goes without saying.
“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?”
yes, I don’t think I can get the permits to build my own clean power plant, or the money to buy a new car AND cover my roof with solar panels (if they’ll even provide enough for the car) AND build a windmill (even if local regulations let me). I’m not a millionaire and neither are most people. Buying an efficient car and improving our windows/doors and insulation in our homes is often the most we can afford.
To start with the air power tools we have used forever
operate on rotary power.
Was there any mention of the engineer in argentina, I believe seen in the, earlier this year, EV report.
He is experimenting with a 6 port rotary engine that i’d love to hear about!
The down side I imagine is in the loud noise of escaping air… Used on big trucks no one will notice. Lets start improving all possibilities.
warm regards,
Emilio
We need a third party verification done by a credible institution or scientific and engineering organizations about the specifications and performance of the air car. If there’s none, the claims are primarily bogus.
The analysis of emissions is flawed. The range of 800+ miles is achieved (theoretically — they have never managed to get a prototype to go more than 7 miles) by using gasoline to heat the air. IIRC, they figure 8 gallons of gasoline.
Summary:
1. You used bogus data supplied by a company known for promising the moon and never delivering.
2. You ignored the fossil fuel that they intend to burn, even in their theoretical, never-built model.
Air car has several other advantages. The materials in the car are not “chemicals”. When the car is constructed and then dismantled the pile of stuff is less complex. Second, I agree that the charge and discharge cycle for a good battery is better then an air tank, but neither is as good as an ultra capacitor. The nice thing about the air car is that the heat losses occur in the owners garage and there can be used for hot water or space heating. The storage of the compressed air can be done at home by PV or wind as the energy is avaliable and the air, with the heat of compression removed, can be transfered to the car quickly or used for air conditioning in the home. PV is especialy attractive since the dark part of the year would provide heat and transportation and the sunny seasons would provide AC and transportation with all the heat rejected.
Contrary to what the article says, the air car is NOT in production in India. A month or two ago Tata officially announced that the car is still in the early development phase and is definitely not going to be produced in the near future.
MDI has a history of promising that their car will be in production “next year”. This has been going on for over a decade.
There haven’t been any reasonable prototypes. Mockup, yes. Working prototypes have been limited to a couple of very very limited capability (<10km) range test runs.
Vaporware. Investor scam. Ponzi scheme. Self delusion. Take your pick of what terms best apply to the MDI air car.
Doing a carbon footprint analysis on a spec sheet for vaporware is a joke.
instead of using gasoline to create pressurized air why not use electric motors to create the same results? they can turn higher rpms, the energy used is easily replenished, and ZERO emissions. as long as we, the people continue to use oil products to fuel the world, oil companies will continue to prevail.
Air tools are great for mechanics because they do not get hot like electric power tools and pack a lot of power in a small tool. A small air die grinder that fits in the palm may put out a peak 3 horsepower (2.2 Kw) while actually getting colder the harder it is worked. It will run all day at full load if the air compressor can keep up. An electric die grinder that is larger but still fits in the hand may be rated 1/4 HP (less than 1/5 Kw) and gets HOT! when it is working hard. Air tools are NOT energy efficient. Air motor vehicles suffer from the same handicap - low efficiency - PLUS the compressed air tanks are HEAVY. It takes a LOT of power to compress air. A LOT of heat is wasted (that’s why air compressor cylinders have deep fins and cooling fans).
Batteries and chargers are quite efficient today - over 90% charge-discharge efficiency for high efficiency batteries and chargers. Advanced design electric motors are also very efficient.
Both air motors and electric motors can be used as generators or pumps to regenerate part of the power used, when braking or holding back speed on long steep downgrades. Lightweight electric motors built into the wheels eliminate heavy, power-wasting gears and shafts, and put the motors out in the open air for efficient cooling of what heat is wasted. The weight of wheel motors is partly offset by the reduced need for large, powerful friction brakes. Friction brakes are normally used only for final stopping at low speeds, so they can be quite compact, or even “old-fashioned” and cheap drum brakes. The wheel rims themselves can have the motor rotors embedded in them with the stators integral with the wheel bearing carrier hubs/knuckles. Antilock braking is very easy to set up when using the in-wheel propulsion motors as generators in braking. Emergency braking beyond the drag from using the motors as generators can be provided by reversing the motors, though this uses a lot of power.
Electric regenerative braking has nothing in common with electric brakes as found on utility and travel trailers. They are conventional drum brakes actuated by electromagnets. Automotive motor-generator regenerative braking is very efficient and reliable, requiring little maintenance. Total failure (very improbable) of one wheel motor can be compensated for by the antilock braking function to prevent “pulling” to one side.
Air cars require air compressors. They are heavy if carried on the car (for plugging in wherever parked) so the large, heavy compressors that will recharge the tanks on air cars would be installed in home garages. They could not be recharged by ordinary service station compressors, as even the ones used in repair shops go only to about 175 psi. Compressors more like the ones used to recharge scuba tanks (2000+ psi) would be used to recharge air cars. 10,000 psi is more like what would be needed.
For greater charge density liquid air could be used, but this requires in addition to high pressure powerful refrigeration to liquefy the air. And liquid air is extremely cold, so in a tank-bursting collision it would be very dangerous (anyone around would be frozen) PLUS it would support combustion as it vaporized.
If modern high efficiency batteries are smashed, only a small amount of jellied or paste electrolyte, which is nothing like as hazardous as gasoline, could be released. If properly designed, short circuiting would be impossible.
I’m sorta over the air car since I saw this google video about a device that converts the earth’s electro-magnetic fields into rather sizable, seemingly inexhaustible pulsating DC source.
I realize this is off-topic, but these things could power vehicles as well as everything else apparently completely off grid, anywhere on earth. Since their seems to be intelligent folk interested in alternate fuels, I thought I’d see what kind of info I can gather.
http://video.google.com/videoplay?docid=167210479374903373&hl=en
As an Electronic/Computer Engineering specialist, I can visualize this concept working, and the only way I can see this being a hoax is if there were huge transducers radiating at a harmonic of the coils he uses… otherwise, he’s onto something, but the vid (and patent application I researched) date back to summer 2006 and I haven’t heard a peep anywhere but in this vid about it.
Any comments welcome!
Brian