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Use wind turbines to compress air for compressed air cars?

March 9, 2013

Remember Tata Motors’ plan for a car that ran off of compressed air?  There was a lot of talk about this back in 2009.  They planned to bring such a vehicle, based on Motor Development International’s (MDI) technology, to market by 2011.  But there were many technical problems, with some potential show stoppers.  The compressed air car was not seen as terribly efficient because of various conversion losses, using electric or gas-powered motors to compress the air.

What if?

But what if the compressed air could be acquired without and electric or gas motor?

I have always wondered if this might be an ideal use of wind turbines.  Electrical energy from wind turbines, like electric energy from photovoltaics, suffers from the lack of a practical storage method.  Let’s say you want to run your electric car off of energy from a wind turbine.  Kinetic energy of the wind is converted to mechanical (kinetic) energy of the turbine, which is converted to electrical energy in the generator (suffering from grid losses as it is delivered to your charging station), which is converted to chemical energy in your battery, which then converted back into electrical energy for the magnetic coils of the motor, which is converted back into mechanical energy to turn your wheels.

What if the mechanical energy of the turbine  instead used to compress air or another gas?  A compressed air car pulls up to the storage tank of the turbine compressed air, fills up and drives away.  No generator, no transmission lines, no battery and no electric motor conversions involved.  This would take advantage of the best features of wind turbines and compressed air cars, eliminating some of the losses that make each of them less efficient.

Fluid compressing wind turbine system

I started thinking about this again today when reading about a proposal by Winhyne Energy Group to build a turbine system in Wyoming in which the turbine would compress a fluid instead of turning a generator.  The compressed fluid would them either turn a generator, or be stored to power the generator when the wind was not available.

Here is a schematic of a single turbine/single generator system…

Turbine compressed fluid system designed by Lancaster Wind Systems, Inc.

Turbine compressed fluid system designed by Lancaster Wind Systems, Inc.

Couldn’t something similar be done to compress a gas?

New life for compressed air vehicles

While Tata Motors’ bold claims of bringing a compressed air vehicle to market by 2011 fizzled, the hope is not dead.  Last year Tata said it was done with its first phase of development and it ” has now been successfully completed with the compressed  air engine concept having been demonstrated in two Tata Motors vehicles” and that they were now in the second phase  and and that MDI and Tata “are working together to complete detailed development of the technology and required technical processes to industrialize a market ready product application over the coming years.”

Note that the recently announced Peugeot compressed air car, to be marketed by 2016, is not really the same thing.  This is a hybrid system has a gasoline or diesel engine and does not have an air tank that you “fill up” with compressed air.  Rather, is captures braking energy to compress air, which can then be used for acceleration.  This concept offers great fuel saving potential in cities where frequent stop and start driving causes large energy losses to braking.

3 comments

  1. A couple of years ago there was a company that built a few wind-powered air compressors for utility scale stored power system. They quickly decided that it worked better to put an electric generator in the nacelle and have the compressor on the ground.

    The electrical generator providing power to an electrically powered compressor uses the flexibility of the electrical system to better match wind speed to compressor load. It is in many ways similar to how a diesel electric locomotive uses electricity as an alternative to a mechanical or hydraulic transmission system.

    Siemens did make a few diesel-pneumatic locomotives but compresses air was less efficient

    A good source of info on MDI and aircars in general is http://www.aircars.tk.


  2. […] Use wind turbines to compress air for compressed air cars? […]


  3. Compressed air is as efficient as Lead Acid batteries. But unlike batteries it does not loose efficiency with time as Lead Acid cells do.
    Prehaps the best idea would be to have compressed air trams (such things were common it the late C.19th early C. 20th in France) From the 1870’s until the 1990’s compressed air locomotives were built for the mining industry. The last being built by KONSTAL in Poland in 1992. Provided you could use the energy(heat) derived from compression as a part of the design and the air was supplied by either wind or water power you could have quite a friendly system. In fact the Vichy to Cusset tramway which closed at the end of the 1920’s used a water turbine in a converted textile mill to compress the air. However compressed air would only see niche usage. As for cars to make air efficient it would have to be quite high pressure say to something like 200-250 bar, The question then is do you want air at that sort of pressure in a car?



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