Quote:
Originally Posted by Gregte
When you compress air it generates heat. Between the time you compress the air and the time you use this air to power a vehicle that heat dissipates away. That is a very large loss of energy.
It reminds me of the gasoline ICE. Most of its inefficiency is due to the wasted heat which is generated burning the gasoline.
Can someone shed some light on this issue for me?
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This does indeed effect the overall "well to wheels" efficiency calculations. But you are taking energy from a large, fixed power installations and storing it for later use in your vehicle. Even if you lose 50% of the energy to heat of compression, you may still come out ahead as far as pollutions, since you can more easily install pollution controls (and perhaps even carbon recapture equipment) at the the large electric plant.
The big issue for compressed air vehicles has been that compressed air is a rather heavy, bulky way to store energy. This limits the operating range.
MDI is trying to get around this by adding an EXTERNAL combustion chamber to heat the air. So their latest series of announcements has been "dual mode" operation --- compressed air only for low speeds and/or short ranges and external combustion for longer ranges.
Unfortunately, it is hard to tell if this is all just speculation or whether they have actually done what they claim. MDI has a history of announcement of "production soon" of cars with great performance, but then never delivering.
This was true with the 2002 production dates by MDI and Zero Pollution Motors of the e.Volution car in South Africe. Also true with the air powered taxis for Mexico City a few years later. And the eolo car by MDI in Italy in 2004 time frame. And many other missed promises by MDI -- almost every year since 2000.
Part of the problem may be the business model of the company. MDI does not intend to make money by building cars, but instead by selling license and franchises. Just like in a pyramid scheme, what counts is being able to sell more franchises, not the ability to deliver.