It’s a poor storage medium. It heats up as it gets compressed into the tank and that heat must be removed. That heat gets wasted. It’s a significant amount of energy.
“It heats up as it gets compressed into the tank and that heat must be removed. That heat gets wasted. It’s a significant amount of energy.”
You’re right about that. In post #58, I mentioned that the expanding gas can be used to cool a vehicle — which would save the energy otherwise used by an air conditioner. That makes the concept a lot more practical in hot climates than in cold ones. The Tata AirPod prototype can use the expanding air for interior cooling.
The heat released during compression could be used to heat water. A commercial compressor station attached to a e.g. a hotel or restaurant could save on their water-heating costs.
I’m not trying to “sell” this concept — but, I do enjoy design challenges.
The heat is not caused by compression. What happens is that all of the heat energy in a large volume of air becomes concentrated, causing the temperature to increase. That being said, any process of energy storage and/or conversion results in losses, so the real test is would be a cost vs. performance comparision against other technologies. Compressed air won’t store nearly as much energy as the same volume of energy as gasoline but I would expect in to have a much higher energy density than the best available batteries and the charge time would be reduced by at least an order of magnitude.