A pet peeve

I just came across this story with the headline, "New Pollution Free Car runs on Air:"

BBC News is reporting that a French company has developed a pollution-free car which runs on compressed air. India's Tata Motors has the car under production and it may be on sale in Europe and India by the end of the year.

The air car, also known as the Mini-CAT or City Cat, can be refueled in minutes from an air compressor at specially equipped gas stations and can go 200 km on a 1.5 euro fill-up -- roughly 125 miles for $3. The top speed will be almost 70 mph and the cost of the vehicle as low as $7000.

Sorry, but that's not pollution free. You have to use energy to compress the air, and unless that energy source is pollution free, the car is not pollution free. Yes, it may be easier to find low polluting energy sources to compress the air than to run a car engine, but it's not automatically pollution free, and if the source of energy to compress the air is electricity, it might even cause more pollution than a regular car, depending on the source of the electricity. I wish the press would report these things accurately.

Wasn't the law of conservation of energy one of the first things that was taught in grade school physics? If it takes so much energy to drive a car, then that energy has to come from somewhere. If not from gasoline engines, then from burning coal to make electricity or whatever. And, the more times you convert from one energy source to another, the more you lose in waste energy due to inefficiencies in the conversion process. If I recall correctly, you can only get about 30% of the energy in the coal into electricity when you generate electricity. And, when you use the electricity to compress air, you'll lose another significant percentage.

Now, I'm not against these cars at all. Sounds like it might be a good idea. But, unless we come up with low polluting ways to compress air, this is not a "pollution free" solution.