Question

One way to store a lot of energy is to compress air in a large cave. The air starts at the corner marked by the black dot, where P = 1 atmosphere, V = 1 cave volume (let's choose 1,000,000 cubic meters), and T = 300 K. It is then adiabatically compressed to half the volume by a pump. As the air comes out of the pump it is hotter (how hot? what is the pressure?), but it cools to 300 K again at constant volume (what is the temperature now?). Later, the air expands adiabatically running a generator, ending at the initial volume. It is now colder than 300 K (how cold?) but it warms up to end at the original temperature, pressure, and volume.How much work did the pump do? How much energy was given to the generator

Answer 1