Quote:
Originally Posted by cmittle
Bad idea. Compressing air takes a lot of energy. And we know from the first law of thermodynamics the energy output of a system can not be higher than the energy put into the system. And because these cars use the compressed air as a propellant (as opposed to a fuel) we already know that the amount of energy put into compressing the air will be significantly more than the energy that will be put to the road. When you throw in the efficiencies of the entire drivetrain and wind resistence etc... I'd bet that you don't come out much above the 20% energy throughput that an ICE gets. Heck in all reality you'd be ahead if you cut out the air compressor and just used the motor that drives the compressor to drive your car.
If you're looking to save money because running the air compressor at your house is cheaper than filling it with gasoline that's a good car to look into. Just don't be fooled into believing that they are better for the environment than a properly tuned gas or diesel ICE.
My $.02
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I wonder how far off the direct efficiency is compared to that of an electric car. The obvious benefits of air>electric are with the battery pack. No battery wear over time and recharge time is much much faster (my 100cuft scuba tank is refilled in >10 minutes to 3,000psi). Then, what's the impact when you take into consideration costs of battery replacement (at whatever interval), tank maintenance etc. for a 50 mile range EV and a 50 mile range Air.
Then, of course, an EV trumps an air by not having reciprocating components and mostly solid state parts. I would think that the components of an EV will last much longer (save the battery).
I think, however, air recharging would need to be a more centralized process such that it can be done more efficiently, with multiple stages and inter cooling. Because yes, compressing air (corollary would be refining crude oil) does take a lot of energy, but that doesn't mean we should make it an inefficient process on top of that
But, that's not exactly what this company is doing....
I like that the cited FE numbers are reasonable - 2L/100km @ 55mph (miniflowAIR model).... And apparently they're using external combustion
I also like their backup generator concept/product.... While there's power available, it recharges itself... When power goes out, it runs off it's compressed gas tank. Much like the large electric-flywheel power supplies of yore