4 ms·
It’s absolutely misleading. The compressed air absolutely has potential energy. Nail guns, air wrenches, etc convert that potential energy into kinetic energy.
by SkyPuncher 2y ago
It’s absolutely misleading. The compressed air absolutely has potential energy. Nail guns, air wrenches, etc convert that potential energy into kinetic energy.
It seems like either this is describing an additional energy storage/extraction method that’s possible with these systems. Either to improve the efficiency or something that’s actually far more efficient than utilizing kinetic energy compressed air can create.
It’s kind of like saying the water in a hydropower plant doesn’t store energy. The turbines aren’t extracting energy from the water itself. They’re extracting energy from gravity acting on water. It doesn’t matter if the water is nearly freezing or nearly boiling, it has roughly the same amount of hydropower available.
- pfdietz 2y agoYour analogy is nonsense. Water in a hydropower system falls from a higher gravitational potential to a lower. When a pumped hydro system is charged, the water is moved up and energy is stored in its potential. This is not the case in a CAES system. The internal energy of air, which is the kinetic energy of its molecules, is independent of pressure. It's only a function of temperature. The internal energy of the air is unchanged by a process that increases its pressure without increasing temperature. So, no energy has been stored in the air. What has been done is reduction of the entropy of the air. So, it is now possible to convert some of that internal energy (which was always there) to work by expanding the air. The air would end up even colder than the initial air.